# Kozo A3 in 1.5" scale



## kvom

I have gotten a little "burned out" on the paddle steamer engine, so in the meantime I have started on building the Kozo Pennsylvania A3 switching locomotive. This will be the 1.5 inch/foot (i.e., 1/8 size) and will run on 7.5" gauge track.

I have made a start on the frame, which has 5 main pieces: 2 side rails, a front bumper, a rear footplate, and a crossmember. I didn't take any pics milling the side rails from 1/2x2.5" CRS, so here are a few more recent progress shots.

The left side rail needs a 1.125" hole for the blowdown valve. My latest drill is 15/16, so I bored it out:







Next, fabricated the rear footplate from 1.5" square CRS milled down to 1.25x1.25.






I used the footplate holes as a drilling template on the side rails:






The frames are too big for my little tapping stand, so I used the mill spindle to start the 10-32 tap straight.






Here are the side rails, foot plate, and crossmember in "position". I'm waiting to get fasteners from Enco. The crossmember needs to be remade due to "operator error".  :






Next is the front bumper, made from 1.5x1.5x13.375 CRS. After milling and drilling the mounting slots, I used the CNC mill to round the ends:











The front bumper will get a lot more threaded holes, but I'll hold off until I make the parts to mount there.

The engine has a few hundred parts to make, but these are the largest sizewise. The side rails are 3' long, and are the largest pieces I have ever machined. Though the Bridgeport table is 9x42, the spindle X travel is abou 24" max, so I needed to move the rails sideways a couple of times to mill and drill all the features. For alignment, I use a pair of ground rods that fit in the table slots. The pieces are pressed against these rods before clamping. I used parallels under the rails to clear the table.


----------



## kvom

Managed a bit more progress by milling the opening for the tee in the side rails. First CNC op was a pocket using a .5" roughing endmill leaving .025" clearance:






Then a finish profile cut with a .25" carbide endmill:






After deburring the edges:


----------



## ozzie46

Neat work Kirk. I'll be following along. I'm in my recliner and the channel is set for HMEM Kozo!  ;D ;D ;D

 Ron


----------



## slick95

Very cool kvom

I'm going to be following this through to steam   

Just beginning the A3 myself in 3/4"

Keep it going...

Jeff


----------



## kvom

A main difference in the 1.5 scale vs. 3/4 scale versions is the need for brakes on both the engine and tender. Today I made the first of many parts comprising the braking system. The spring stirrups straddle the side frames, rest on the axle boxes, and connect to a leaf spring assemble above.

Starting with a length of 1x1" CRS, I successively milled the slide profile for the four stirrups:






After cutting off at the bandsaw, the rest of the milling was manual:


----------



## 1hand

Kvom your making some real strides on your loco. Thm:

I'm on the other hand having trouble finding time with work and kid functions this time of the year to get any shop time. Things should free up a bit after the first of the year I hope.

Keep up the great work!
Matt


----------



## kvom

Looking to see some progress from you matt! 8)

The 1/2" stainless 304L rod arrived from Enco, so I decided to make the 22 spacers for the fire grate. Drill 1/4", then part off .21" doughnuts. 






Since I had to order 6' of the rod, I also made the two brake beams from the same material:






I still need e-clip grooves on one and fit the ends to bushings on the other.


----------



## kvom

The stainless bar stock showed up, so I decided to continue building the fire grate. The stuff from Enco is 304, not 304L and is pretty hard to work. I started sawing off 7.5" sections, and by the 5th piece my band saw blade was shot. In reality cutting with a roughing endmill would have been better. I had to go to school anyway and was able to cut off the remaining 5 pieces plus an extra while there.

Back home I used a 1/4" carbide endmill to cut to length. Here's my setup on the Bridgeport:






Afterwards:






It seemed to cut best with a fairly fast feed; my DRO showed me turning the y-axis at 10ipm. I then set up a stop on the fixed jaw to drill the 1/4" holes. Again, both the center drill and drill seemed to like a like of steady, heavy pressure. For the 1/4" drill I needed to peck twice to clear the swarf, and avoid chips welding to the drill; I used lots of cutting oil too. Afterwards I used a 60-degree countersink to chamfer all the holes.

After turning two pieces of 1/4" SS rod to length and center drilling, all the parts are ready for assembly:











The total width is .04" short of plan. I don't think that's significant, but I will wait until I've made the support rails and checked fit before staking the assembly.


----------



## kvom

Most of today's shop time was spent working on the grate supports. All the machining is manual on the Bridgeport as I was also researching a suspicious noise on the CNC mill. In any case, I will finish the front end profiles and the latch pockets via CNC later on.

Here's today's output:






And a trial install on the frame with the grate:






UPS showed up this afternoon with my order of bearing bronze and a 7/8" reamer, so I can start working on the axle boxes and drivers next.


----------



## 1hand

kvom  said:
			
		

> Looking to see some progress from you matt! 8)



Only 30 more years til I will be able to retire, and do this full time! oh:


----------



## ChooChooMike

WOW kvom !! You've taken on quite a challenge ! I get the sense that you're up to it too !! 

I have all of Kozo's books, and drool over them. Don't worry I have an appropriate drool catcher ! :big:

I just bought a 1-1/2" scale Mogul (2-6-0) casting kit from Gene Allen (Allen Models). So that'll be a huge multi-year project for me, especially seeing I don't even have large enough lathe/mill (I have Sherlines) to make most of the parts. I'm pretty sure I have access to a coupla folks shops and their help, so that'll get me started anyway. I'm thinking by the time I really get going, I'll have a bigger place and room for conventional-sized machines.

Mike


----------



## Paolo

Hello kvom
I have all of Kozo's books, and drool over them...For the moment I'm looking to see some progress from you and learning!!!!
Best regards
Paolo


----------



## kvom

I spent the best part of the past two afternoons working on the axle boxes. These are to be made from phosphor bronze. Since this material is mostly available in round rod, I calculated that the end dimensions of each half of a box could be fabricated from 1.25" rod, although ~50% ends up as swarf. Being conservative of the material, I parted off 8 sections 1.91" long (.10" over), then faced both ends of each piece. Before going into mass production, I did the first piece solo to check on the machining qualities of the material, which was new to me.






As each of these pieces represents about $7.50 material cost, I proceeded slowly, measuring frequently, to arrive at 8 nearly identical blocks:






Four of these represent the bottom halves, and need 4 through clearance holes for 8-32 screws. A small piece of aluminun underneath spared the parallels. The holes were then counterbored.











The four tops were drilled 3/8" deep and tapped 8-32. I started the first couple of threads in each hole using a tapping stand, then finished to depth with a normal tap wrench.











I left it for the day with the two halves fastened together with screws. The next operation will be to mill side slots to fit individually to the pockets in the frame.






Before quitting for the day, I took the first step and turned the treads on the driver castings. Measuring with the DRO on the lathe, the treads have a diameter of 6.63", which leaves a lot of extra material assuming a final tread diameter of 6.375.


----------



## hammers-n-nails

looks like your making good progress. i got as far as ordering part of the castings for a 7.5"ga loco before i changed my mind. you may be interested in this mans videos i found on youtube http://www.youtube.com/user/trainman4602 . i notice you give a diameter for the tires, did you turn them straight or at an angle?


----------



## kvom

The first turning is not the final tread, but just gives a surface to mount in a 3-jaw chuck. The next step is to chuck on that tread, face the back, and drill/bore the axle hole. Once the hole is done, the rest of the machining (incl. the tread profile) is done with the wheel mounted on a mandrel fit to the hole.

The final tread diameter is not critical, but all 4 need to be the same.


----------



## zeeprogrammer

Nice progress kvom.
I need to get those books.


----------



## kvom

I had a short shop day, so not as much progress as I'd hoped. The first order of business was to mount the 3-jaw chuck with the soft top jaws, and to turn a pocket that matches the 6.63" tread diameter that I'd turned previously on the driver castings. As long as I don;t remove the chuck, I should be able to take the casting on and off the lathe without losing accuracy.






I then faced each of the drivers' inner sides, turning at 300rpm and .001"/revolution. Quite a slow process with lots of messy black powder coming off.






The final op of the day was to center drill.






I had borrowed a 27/32 drill from school intending to drill the axle hole prior to reaming it, but realized that it was a 4MT rather than 3MT. Since I have a brand new, US made 13/16 drill bit with a 3/4" shank, I plan to use it and then bore the hole 1/32 larger before reaming 7/8. Before I do that to the first of the $80 castings, I'll check it out on some aluminum to make sure I don't overbore the hole.

I also realized I should have faced the outer side the same time I turned the tread. It's not a big problem as I can do it with the soft jaws as well; just extra work. Once I'm finished with the soft jaw setup, the rest of the machining will be done on a mandrel to cut the tread/flange profile.


----------



## rklopp

Kvom
I'll bet the wheel turning job made you appreciate the 10EE lathe. Lot's of beef to dampen the interrupted cut from the spokes. How many hot cast iron chips down your collar???
RKlopp


----------



## kvom

The CI comes off in grains, like sand, and not very hot. I just took .06 per pass, so th interrupted cut was no dramatic at all. In any case, I must sit out of the "line of fire" and watch the DRO wind down to 0. I originally set the gearbox to feed at .0005/revolution. With a 7.5" diameter at 300 rpm, that's a 50 minute job per pass. I found that at .002/rev the finish was just fine.


----------



## kvom

Today's afternoon effort was more work on the drivers. After first taking a skim cut from the outside face, I proceeded to drill/bore/ream the axle hole from the inside face. I tried it on a piece of Al first to make sure that the hole after boring was still smaller than the reamer.

Drilled with a 13/16 drill; 500 rpm:






Next, bore to .843:






Finally ream to .875 at 200 rpm:






Buying the .875 reamer is likely a good "investment" as I still need reamed holes in the axle boxes and axle eccentrics.

I was trying to determine how thick the drivers should be, as this would determine the length of the axles. After doing some figurings based on the distance of the cylinder center bore from the frame and the thicknesses of the rods, it seems that the IBLS minimum of .750" is what I'll need, as that leaves a clearance between the inside face of the drivers and the axle boxes of 1/16". Given that, the axle length is 8.62 in order to fit the 7.5" gauge track. At their current state, the drivers are ~.88" thick; I plan to take the remaining .12" off the outside face to avoid reducing the cross section of the spokes any further. One the drivers are at proper thickness, the rest of the machining will be done on a mandrel, to be constructed.

I am considering the best way to form the .094 radius fillet between the tread and the flange. I think I probably need to grind a HSS blank to get the proper form, or else purchase a rouund carbide insert and holder. Alternatively, I may just wait to turn the flange and tread profile on the CNC lathe at school


----------



## ozzie46

That looks nice Kirk. I'll be following along. You do very good work.

 Ron


----------



## kvom

Thanks for looking in, Ron.

No pics today. I finished facing the drivers down to a thickness of .751, then decided to make an axle to fit the holes created yesterday. I cut a piece of 1.25" steel rod and faced/center drilled each end for a length of 8.8", leaving room to remove the center holes later if desired. I turned one end to .875 using the 6-jaw chuck (seemed a good fit when tried with a wheel), then turned the rest of the axle with the turned end held in a collet. At the finish, using the same insert and DRO setting, the collet end measured .873 and the end held by the live center .871. Since I will be fixing the wheels to the axle with Loctite 620, which is good up to gap of .015, it should work.

The rear axle needs to accept two eccentrics for the water pump and lubricator, so I'll use today's axle as the rear. For the front I think I'll just turn down each end for a length of 2" or so near the spindle, and leave the center thicker.


----------



## kvom

After spending the morning with my truck leaking fuel all over the driveway and street (hopefully just frozen o-rings in the fuel bowl), I did some more work on the axle boxes. The goal is to mill slots along the sides that fit the pockets milled into the frame.

Although the frame mic out at .515, the slots cut with a .500 endmill fit very well. So my guess is that there is at least that much runout on the mill spindle or the collet. In any case, I "whittled" the first one down until I had a very tight fit, and then added .006 as per the tolerances Kozo implies in the book. This allows a little front to back flex on the axles.







I then made a start on milling stock to size for the retaining bars that attach to the frame under the axle boxes.


----------



## kvom

Today's work started with finishing the axle box retaining bars and fitting them to the frames. Here's my setup for spotting the mounting holes:






Next, I wanted to mill the two slots on the top sides of the axle boxes where the spring stirrups ride. As there are 8 slots, and I would be using two endmills (1/4, 1/8), I just developed a simple CNC program to mill them repetitively:


----------



## Jeff02

Man at this pace youre going to be blowing your safety before spring!


----------



## kvom

Jeff02  said:
			
		

> Man at this pace youre going to be blowing your safety before spring!


I'll probably blow my mind first ;D

Today's work was to finish the bores in the axle boxes. I decided to use a CNC technique I hadn't tried yet, which is milling a hole rather than drilling it. The method is to have the endmill make circles around the center while steadily lowering the Z-axis. For me the advantage was being able to mill a 27/32" hole while not having a drill that size.  Additionally the hole is rounder and straighter in theory than a drilled hole.

I first center-drilled each box, and then a .5" hole to allow the milling swarf to fall through rather than accumulating in the hole as it deepens:






The program used a 2-flute 7/16" endmill at 3000rpm and 20 ipm. Each 360-degree turn around was .010" deeper.

Next I used the .875 reamer on each bore. This reamer is over 7" long with a 3/4" shank, so not suitable for a mini-mill. It's not really necessary to ream the bore, but since I used the reamer on the drivers the diameters ought to match closely.


----------



## Henk

I like the design of the retaining bars in that their shape (and the shape of the frame) should function to keep the frame from flexing - while not depending on the force supplied by the screws. 

And as the others said: Oh my, what a progress...


----------



## kvom

It seems to me that the main function of the retainers plus the two piece boxes is the ability to remove the bar and the lower bearing half to re-lubricate the stuffing for each bearing. Today I needed to mill the pocket where the lubricated cotton is placed in the axle box lower half. I did these on the CNC mill after first verifying the program on a piece of aluminum scrap.






Then I decided to make a start on the brake lever bracket (drawing 6 on p213). The first step was to mill some 1x1x2" bar to nominal piece dimensions, and then drill the 5 through holes in each. Then two two mounting holes (8-32) were counterbored. Again, all done on the CNC mill.






Then I mounted a piece of aluminum in the vise, and drilled/tapped two 8-32 holes to match the holes drilled in the parts. I then attached the brackets to this fixture with 8-32 SHCS.






The outer profile of the bracket could now be milled using a 1/2" 4-flute endmill @ 1200 RPM. I kept the feedrate down to less than 10 ipm, although I suspect it could have been done faster.






The result of a couple of hours shop time:






The rest of the work on these parts will be done manually on the Bridgeport. No further progress foreseen here until after Christmas.


----------



## zeeprogrammer

kvom  said:
			
		

> No further progress foreseen here until after Christmas.



Noooooooo! Say it ain't so!


----------



## kvom

Back from Florida, suffering a head cold, so not much time in the shop this afternoon. I finished up the brake lever bracket, which involved primarily milling slots. With a 1/8" endmill in steel, you can't push it; so the narrow slot was .025 DOC at 2ipm. I'm glad the BP has a table drive, else that's a lot of cranking.






I did manage to do some CAD/CAM on some other brake parts to be done later this week.


----------



## kvom

I got 1-1/3 part done today. The 1/3 part is the center section of the brake lever beam. Making this was a bit of a PITA, but it came out OK in the end. I used the same 304 stainless bar as for the fire grate:






It's a tight sliding fit onto the beam that I made previously. I will eventually fasten it permanently with green loctite and possibly a roll pin as well.

The other part is the brake pedal bracket (fig. 3-12 on p. 215). The first operations are on the CNC mill on a piece of CRS 2.5x1.4x1.3. 






Then after removing the remaining "corner" remnant with a hacksaw, the bottom section could be machined off on the Bridgeport:






After a bit of filing to cleanup the edges, I drilled the 4 through holes for 8-32 screws:






Then after countersinking two of the holes on the bottom, a test fit onto the frame footplate:






It seems to me that some of these parts are drawn for elegance of form, as they are not easy to machine as drawn, and a simpler, more oblong profile would work just as well.


----------



## kvom

After an off day yesterday, I had almost an entire workday in the shop today while all the women were out of the house. Seems there should be more to show somehow. The productions were 4 parts of the brake pedal as drawn on p. 215, plus the bushing for the brackets. I just used a 1-piece bushing with a press fit rather than the 2 pieces loctited to the bracket.






It still packs the actual pedal piece, as I don't have proper size material. I'm also unsure if a Mapp gas torch will heat the steel bar enough to bend 90 degrees as stated in the book. The design also defers connecting the two sliding parts of the lever bar until final install, so as to orient the pedal at the proper angle for comfort.


----------



## kvom

I purchased a lathe tool for cutting the profile for 7.5" gauge train wheels from a builder on the Home Machinist board, so I am now in a position to cut the flange and tread on the iron driver wheel castings. To ensure concentricity with the 7/8" center bore, it's necessary to turn a mandrel that's a good sliding fit for the bore. The first task was to turn an aluminum washer for clamping on the mandrel, and I made this from a piece of 1-1/8" aluminum, drilled for a 1/2" screw and parted off .3" thick. I then turned the mandrel from a length of 1-5/8" aluminum, taking the last cuts .001 at a time until the fit was achieved. As I had reamed the drivers, I found that all had the same good fit as the first. I then drilled the center of the mandrel for the 1/2-20 screw I found in my bolt bin (1/2-13 seemed too hard to thread as my tap is a crappy carbon steel one).

Not wanting to experiment with a $75 casting that has a lot of work in it already, I had previously made a blank "wheel" from some 3" aluminum round, drilled and reamed to the same bore as the castings, and hence a good fit for the mandrel. Here's the trial wheel mounted:






Rather than a full cut with the profile tool, I turned the blank to 3 separate diameters:
1) Flange diameter fully across
2) intermediate diameter .25" less and .156 from inner edge of the wheel
3) tread diameter .375" less than the flange and .234 from the inner edge
I then used the compound set a 3 degrees to turn the tread, stopping at the edge of the intermediate cut






Now the profile tool is aligned with the inner edge:






Finally I advance the cross feed slowly until the outer radius meets the tread. Even being aluminum there was a fair amount of chatter. It looks as if I needed to go in a couple of thou more, although I doubt it's critical.






After a little polish, I can take this to the club's new years day party to get feedback from the other members.






Of course, the mandel will remain chucked on the lathe until the drivers are finished. The edge opposite the flange will also be rounded off.


----------



## 1hand

That's pretty slick!!

If I ever figure out my Lazy CAM turn, I should be able to reproduce that profile on the lathe....I hope.


Matt


----------



## kvom

Doing that profile by hand coding would be easy, and probably good practice in learning the g-code. At our school we do all the lathe work by hand coding as you get better (and readable) code as opposed to what mastercam outputs.


----------



## kvom

This evening I started turning the flange and tread for the drivers. All went well until the flange profile tool grabbed and twisted the aluminum mandrel in the chuck jaws when finishing the 2nd wheel.  :-[  So now it's all out of square, and I'll have to make a new one to finish the last 2 wheels. That can wait until tomorrow.


----------



## Henk

kvom  said:
			
		

> Not wanting to experiment with a $75 casting that has a lot of work in it already



Just out of curiosity : is that $75 for a single wheel, or for the set of four?


----------



## doubletop

This one is definitely on my watch list.

As others have commented you are going through this at a good pace. Are you doing all your own CAD/CAM for this from the drawings or has somebody already done the programming for each of the parts? If you are doing it yourself where is the most time being spent. Processing the drawings or machining the parts?

Pete


----------



## kvom

The 4 drivers were $300 ($75 each) plus $20 shipping.

I am doing my own CAD-CAM for the CNC parts. The CAD is done in DraftSight, and generally is pretty fast to do one part. Note that a drawing will cover only the operations on one side of the part, so several may be needed. Then I load the DXF file into CAMBAM to generate the g-code. While this can be fairly simple, you also have to imagine the fixturing that will be needed to hold the part. For odd shaped parts you may need to use the drawing to generate a separate pocket for the vise soft jaws.  I also use a feed&speed calculator to determine feed rates to plug into the CAM.

I'd guess that overall I spend about the same amount of time with the software as the shop time. I'm dealing with odd-shaped bits of steel gleaned from a scrap bin in a lot of cases, so manually machining to a stock size can take as much time as the CNC machining. Without a tool changer, parts that need multiple tools can take a lot of time, as after changing the toll I need to set the Z height above the stock surface. For this reason, I try to use the same tool for all copies of a part (using a vise stop for positioning).

CNC is most useful for the parts with rounded profiles and odd angles. Rectilinear parts are often faster and easier to make manually. I also like to drill on the Bridgeport where the CNC setup would be time-consuming, or the holes are deep.


----------



## zeeprogrammer

kvom  said:
			
		

> This evening I started turning the flange and tread for the drivers. All went well until the flange profile tool grabbed and twisted the aluminum mandrel in the chuck jaws when finishing the 2nd wheel.  :-[ So now it's all out of square, and I'll have to make a new one to finish the last 2 wheels. That can wait until tomorrow.



As in the the $75 drivers? Is the driver okay?

The shot of the brake pedal in the vise brought the scale home for me. It's not small!


----------



## doubletop

Kvom

I don't want to start a lengthy off topic debate on your thread but thanks for the insight into the amount of work required for CAD/CAM. I'm torn about going the CNC route and clearly there are advantages even if it means available shop time spent in front of a computer. Trouble is that's what I do all day and the shop is a bit of break from all that.

....................back to the A3

Pete


----------



## kvom

Zee, The driver wasn't damaged, but afterwards the setup would wobble.

doubletop, if you don't use a CNC mill, then the rounded parts need to be approached in one of these ways:

1) ignore them and leave them square or polygonal, as they are mostly for appearance rather than fit.
2) Form them with a grinder or sander
3) Build a rounding table; there are a number of threads on HMEM about how to do this
4) Use a rotab, although the setups could be really time consuming

Otherwise, the "wierd angle" parts can be milled via angle bar setups.

I was advised by a member of another forum that I should be using a faceplate for forming the flange, using a bolt against one of the spokes to prevent the wheel from turning. That sounded perfectly reasonable, except that I don't have a faceplate for my lathe. What I do have is a dog driver that I bought used, and that came with an aluminum fixture place that bolts to it. So my goal for the day was to concoct a way of mounting the drivers on this plate. I first sliced off a 1" thick piece of 3" aluminum rod, then faced it on both sides on the lathe. On one side I formed a spigot and flange. The flange I drilled and counterbored for 4 10-32 screws:







The next step was to drill and tap 4 matching holes in the fixture plate, then screw the two parts together:






The ensemble is bolted to the dog driver, then mounted on the lathe spindle (D1-3):






I could then turn the spigot down to a sliding fit for the drivers plus drill and tap the center for the mounting screw. By fitting as driver, I could drill and tap for the driver screw, also 10-32.






Now with the assembly mounted on the lathe, I could put the drivers securely in place and turn the flanges. This went really well and much faster than for the previous method. I ran the lathe in back gear at 100 rpm, and had very little chatter. I also was able to cut the "paint line" in the counterweight.






While this fixture took most of the afternoon to concoct, it will be useful for the next step, which is to drill the crankpin holes. I made this D1-3 mill mount some time ago to allow work to be moved from lathe to mill without unchucking:






So with the mount clamped to the mill table, I'll be able to ensure that all four drivers have their pins the same distance from the axle bore. The driver screw will also act to position all 4 at the same angle.






But that's for another day.  ;D


----------



## kvom

I finished the drivers by drilling the crankpin holes, using the setup from the previous post.











While doubling Kozo's plans would mean the crankpin is 9/16" diameter, I am using 1/2", as I have a reamer for that size. Shouldn't make a difference.

I made a start on the brake lever links, but was unable to finish yesterday. I'll post pics when they're done.


----------



## joe d

Kvom

This sure is coming along nicely. Watching a 75 buck casting going off all over the place would have tested 
my pucker factor...

looking forward to the next installment,

Joe (Who WILL build a loco.... someday...)


----------



## kvom

Thanks for looking in Joe. I think this build is quite a bit easier than the Snow you're doing. It just has bigger and more expensive parts. Other than the boiler, the only parts I'm having a problem visualizing the machining sequence is the brake shoes.

Yesterday and today I worked on the "brake lever links". These parts, two mated on a side, transmit braking force downward, which spreads the ends apart. The ends are attached to the brake levers, which in turn press the brake shoes against the wheels. The profile of each part is the same, so the first step was to CNC mill that profile into some pieces of 1/2" thick CRS. Each part is a bit over 2" long.






Next I mounted aluminum soft jaws on the vise and milled the same profile as a pocket. Note that the jaws are clamped on a thin piece of material while being milled so as to provide some room to actually clamp the piece firmly.






Now each piece can be clamped in the pocket:






And have the "substrate" milled away:






The same pocket is then used to drill each end of each part.






And the final CNC operation is milling the cheek cuts on two of the links:











Then after filing the burrs, I milled the slots on the Bridgeport using a 1/8" carbide endmill. In retrospect, I could have done them faster with less tedium via CNC:






The profile could have been milled manually using angle blocks; the side angle is 3.1 degrees, but CNC makes parts like this a lot easier.


----------



## kvom

The latest installment is machining the brake levers. These parts attach to the lever brackets, lever links, and brake shoes (all shown on p. 213) via pins secured by e-clips. I decided to CNC drill and mill the profiles for all 4 copies in the same operation, using a piece of 12L14 recovered from the school scrap bin. I did spend a fair amount of time in Cad moving the pieces around to fit on the stock with somewhat minimal wastage.

The first operation was to mount aluminum softjaws on the vise, as I would be milling/drilling through holes. I machined a ledge in the jaws to support the work.






Next, the drilling and milling were done. Here the CAM program left holding tabs to keep the parts attached to the stock. The tabs were .1x.1", specified so that they would be removed in the final milling operation.






The profile didn't cut through the material, so I must have miscalculated something; however a facing op on the Bridgeport to remove a few thou from the bottom exposed the part profiles. Then a few minutes work with a hacksaw cutting the tabs left the parts free.






Now I machined the tops of the vise softjaws flat and milled a pocket .120" deep using the profile of the part. Afterwards I found the parts wouldn't fit. It was necessary to rerun the CAM program specifying a negative roughing allowance of .005, which in effect expanded the entire profile by that amount. Now the parts fit securely. Note that for these types of operations the pocket needs to be the mirror image of the part.






Machining the "bottom" of the parts brings them to the correct thickness as well as removing the tabs. Again the CAM program specifies milling wider than the profile to avoid burrs on the edges.






Finished; this material machines a lot nicer than the CRS I used on other parts so far:


----------



## kvom

Keeping this thread on page 1: ;D

Today's part was a pretty quick and easy one once I got into the shop. Again, using CNC with holding tabs to mill out the profile, then filling off the tabs once cut free:






I don't have any 1/8" steel, so anticipating obtaining some I am drawing up all the different spring hangers from p210. I plan to cut all of them from one piece of stock in one CNC run. 

Expecting snow and ice today and tomorrow.


----------



## kvom

I got the spring bands done over the past two afternoons, then fitted the stirrups to the axle boxes via a bit of filing.






I've got the spring steel on order, as well as some 3/16 drill rod for the pins. These pins take e-clips, and hopefully the grooving tool I ground last year to cut some model cylinder fins will work on the clip grooves.

As we've been snowbound here in Atlanta for the past few days, I've spent the time drawing the various parts in CAD. So there's no lack of parts to make when I have suitable stock. I think the valve gear and rods will likely be stainless until proven otherwise.


----------



## zeeprogrammer

It's already beginning to look like something.
Very nice.


----------



## kustomkb

Hey kvom,

I missed the last few installments and all I can say is wow!

Great progress on a pretty serious machine. You have made great use of your new shop and schooling and are obviously a fast learner because your work and techniques are looking great.

Well done! :bow:


----------



## ozzie46

Coming along nicely. Can't wait to see the springs on there.

 Ron


----------



## kvom

Thanks for looking in guys. Spring material is supposed to arrive Friday afternoon, so I might get started on them this weekend. I worked on the hanger brackets this afternoon, but broke my last 1/8" endmill cutting slots in them, so no pics of new parts today.


----------



## kvom

Having been given some 1/8" thick CRS, I determined to make the spring hangers. There are 14 in all of 4 different varieties, including 8 with slots. My goal for today was to make the 6 that lack slots, pending arrival of my delayed Enco shipment with new 1/8" endmills.

Having some 1" wide strip, I cut off 10". To accomodate this on the CNC mill, I milled "parallels" into the soft jaws on both 4" vises; since these were done in a single pass, the vises are automatically trammed to each other. I also don't have to worry about the tools cutting through and striking metal parallels.






One of the 6 didn't work out well, but I did end up with 5 usable hangers. The 6th will be made in the same run as the other 8.






The other task of the day was to drill and tap the mounting holes for the brake lever brackets on the bottom of the side frames.


----------



## kvom

Spent a while in the shop this morning making the drawbar pocket and drilling/tapping the foot plate to mount it.


----------



## kvom

I made some progress the past few days, although not without pain. I was milling the support plate (p112) that attaches the foot board to the running board and broke an endmill from a too-aggressive cut. The piece was also ruined. I went ahead and finished one, but will need to find another suitable piece of steel to remake the other. FWIW, I milled the two pieces as one to avoid the need to SS the two pieces together.

Yesterday I spent the entire afternoon in the shop of a fellow club member and constructor, shooting the breeze and absorbing a lot of RR and knowledge (hopefully some will stick). I had brought over the coil of spring steel, and my friend used his shear to cut all of the pieces for the spring packs to length.

Today I used a 1/8" 4-flute carbide endmill (fresh from Enco) to drill out the center holes in each leaf. I cut the slots in the ends of the top leaves by drilling 3 adjacent holes, then milled them together. Just need to finish the hangers to get the suspension machining finished.


----------



## zeeprogrammer

Those look great. Watching with great interest.


----------



## kvom

Thanks for looking in Z.

Yesterday I spent machining the two axles. These are just two steel cylinders .874" in diameter and ~8.625" long. My raw material is some nice steel rods that were donated to school and free to me. They are 3' long and 1.25" diameter. My lathe is just an inch or two too short to try to turn both axles together, so it went one at a time.

I noticed problem while turning to diameter, in that there was a taper of about .002-3" over 6", with the diameter getting smaller towards the chuck. So I decided to turn to .880, finish the end near the tailstock, then part off and turn the other end plus the center with the piece chucked in a .875 collet. Theory did not meet with practice; while I measured the diameter at .874, once I fit the axles to the wheels it was obvious that the fit was quite loose. A new measurement showed the end diameter to be .007 too small. Since I plan to fix the drivers to the axles with 620 Loctite, that gap is not a problem. However, it's enough difference to allow the axle to wiggle a bit, meaning that the two drivers might end up not perfectly parallel to each other.

My theory on this relates to the fact that the steel was very hot when removed from the lathe. I believe that it expanded during turning; and since the more massive chuck acts as a heat sink, the end nearer to the chuck stays cooler, hence has a smaller diameter. So I think I'll remake these, first turning to .885, then letting them cool down before finishing to .874 or a sliding fit on the drivers.

Since this type of machining is a bit tedious, I decided to spend today making the eccentric that mounts on the rear axle and drives the water pump. This is made from grey cast iron. The disc is 2.063" in diameter, .625" thick, with the slot for the strap being ,44" wide and a diameter of 1.872. I had a piece of 2.5" diameter CI rod left over from another model build, so it went onto the lathe. Turning and facing were no problem. However, I had a lot of chatter cutting the perimeter groove with a 1/8" wide parting tool. I think the problem was that the piece stuck out too far from the lathe jaws. In any case, I put the lathe in back gear and went in super slow. Then cut off with the bandsaw.

Next, I chucked the disc in the milling vise to mill to thickness and remove the saw cut marks. The interior hole matches the axle diameter and is offset .400", giving a stroke of .800 inches to the pump piston. I drilled out to 13/16 with a succession of drills, bored a further .06, and finished by reaming .875.

The final step was drilling and tapping for a set screw. The 3-3/4 scale engine uses a 5-40; Kozo doesn't give much indication about fastener sizes, so I decided to go with 8-32. The hole from the far side of the axle bore is over 1" deep, and too long for my 8-32 tap to thread through completely. I decided to counterbore the hole for an 8-32 SHCS, but even using a normal set screw it makes sense to counterbore the hole before tapping. With the counterbore, a 1" SHCS fits perfectly. Once the water pump is built and everything is lined up, I'll put a dimple on the axle under the screw to ensure that the disc won't ever slip.


----------



## ozzie46

Sorry to hear about the axles Kirk. 

  You seem to be coming along nicely other wise though.
 I keep checking in even if I don't post a lot.

  Ron


----------



## kvom

A most "axle-ent" day in the shop as I succeeded in machining the axles to a good slip fit on the drivers. Starting with the 1.25" stock in the 6-jaw chuck, I turned down to the largest 5C collet (1.125), and from there on I was able to use the collet chuck, which is more accurate. l alternated the axles until both had been reduced to 15/16, at which time I broke for lunch and allowed the steel to return to ambient temperature. From there I turned down just 2" from each end to the target diameter of .874. Once I had the first end that had a good fit to the driver bore, I didn't change that measurement on the DRO and turned the other three ends. By taking short, shallow cuts the metal doesn't heat up and expand as it did previously.

While the resultant diameter fit the drivers very well, they were a tight fit to the axle box bores, but by loosening the screws slightly that hold the two halves together I could rotate the axles in the boxes. The eccentric disc didn't fit well at all, and I ended up boring it out and additional .01.

Once all that was done, I couldn't resist doing a test assembly.






It looks as if I have .10" of sideplay on one axle and .07" on the other. I need to shorter the axles to their final length and paint the drivers, and then I can think about quartering. I was happy to see that the axles turn without too much effort when it's all together.


----------



## doubletop

kvom  said:
			
		

> It looks as if I have .10" of sideplay on one axle and .07" on the other. I need to shorter the axles to their final length ...........



Before you remove it all, don't you need a bit of side play so it will go around the bends in the track?

Pete


----------



## ozzie46

Gives it a whole new perspective when its on its wheels doesn't it? Thm: Thm:


  Looking good Kirk.

 Ron


----------



## kvom

doubletop  said:
			
		

> Before you remove it all, don't you need a bit of side play so it will go around the bends in the track?
> 
> Pete



Yes. If everything matched the plans exactly there would be about .04" of sideplay, so I've a bit more. I've been told that having more is fine within reason.


----------



## joe d

Kirk

It just looks so right sitting on the wheels... I can't resist "stick it together to have a look" either ;D

Looking forward to your next installment.

Cheers, Joe


----------



## zeeprogrammer

I'm also looking forward to the next installment.

Looks great kvom. I bet it feels great too.


----------



## kvom

I ordered paint and prep (POR15, degreaser, etcher, top coat) for painting the drivers prior to quartering. That should arrive Monday.

In the meantime I decided to skip a page and mill some aluminum, taking a break from the steel. Having scored a block of 3x3" 6061 from the school scrap bin, I started on the headlight. After making quite a lot of chips, I had the basic oblong stock milled to dimension.







The rest was just cutting out the chimmney and the angles. My CAD program calculated the angles to several decimal places, but as I have only integer angle blocks I just rounded up. It still came out pretty decent.






The next step is to bore out the cavity for a reflector and lamp, but that will wait until I acquire one and get its measurements.


----------



## kvom

Yesterday's "work" was lots of filing of the spring bands trying to get the leaves to fit. Seems I milled the openings a little too small. I think that in retrospect making the opening about .03 (half a leaf) deeper might have been a good plan. All four now fit pretty snuggly, but some more filing may be called for on final assembly/

Today I made the first of 4 center bolts that screw into the spring band and pass through the center of the leaves to keep them all in place. I started with .5" 303 SS and got this:






Then the same 5C collet was moved to the hex collet block on the mill to form the hex bolt head. I went with the 7/16 wrench size, although 3/8 might have been better.






After parting, I tried using it to assembled one spring pack and band. Getting it all lined up with such a tight fit in the band was a problem, and when the springs are cambered it will be even tighter.  So more filing may be in order soon.

So now I need to make 3 more of the same.


----------



## kvom

I got my package from POR15 yesterday, so now I can attempt to do some painting. POR15 is a rust preventing/restoring coating that is used a lot in restoring cars and other rusty metal. Given that steam locomotives are around steam and water, I figured rest prevention wouldn't be amiss.

Using this stuff is a multi-stage process. Now a friend and experienced builder told me to just use Rustoleum from the rattle can, that option seems too easy. The first stage for POR15 is degreasing, and the kit contains a cleaner called 'Marine Clean'. I diluted 2 cups with water at 5-1, poured into a flat plastic kitchen storage box, and submerged the 4 drivers along with several other pieces of scrap metal of various types. I'll use these scraps as test pieces before applying any paint to the drivers.

After soaking a couple of hours, the metal needs to be removed from the bath, rinsed off, and then sprayed with a 'Metal Prep'. This liquid etches the surface slightly enabling the POR15 to attach firmly to the surface. The metal surfaces get a thin coating of zinc phosphate. The parts are then rinsed in clean water and dried thoroughly. Any water getting into the paint will ruin it. I plan to put all the parts in the oven for a while at 200F to ensure complete dryness.

Now we apply the paint while wearing latex gloves, as it attaches itself very firmly to the skin. My starter kit has 3 1-pint jars, enough in principle to do everything I'v finished thus far. I plan to paint only the drivers at this time, once I'm satisfied that the scrap pieces look good. In principle POR15 gives a smooth, thin coating without brush marks when applied with a brush, so I'll see how that goes.

The final step is a top coat of paint, as POR15 deteriorates from UV if exposed to sunlight. My kit has 3 pints of a semi-gloss black that is supposed to adhere very well to POR15. if the results are as advertised, the resulting finish will be rustproof and extremely hard and scratch-resistant. I'll post pictures of my resuts later on.


----------



## IronHorse

I have used POR15 for restoring cars, It is a really good product. Mostly I used it where I did not want to cut out the metal. A good sandblasting, coat and dry. Just remember to put a piece of plastic wrap between the lid and can or you will never get it opened again. The stuff will weld the can shut  Also if you recoat, you should do it when the first coat is still tacky, you have to sand it if you let it completely harden. 


IronHorse


----------



## kvom

Having a chest cold over the past week, plus band trips for the kids, I didn;t get much shop time lately. I did manage to paint the drivers with the POR15, and have been a bit disappointed with the results. The paint itself is not viscous, and a little goes a long way in coverage. I used a sponge "brush" to apply. On some flat test pieces the results were quite good, but with the drivers it dried a bit unevenly. I sanded the rims and other flat areas and painted on their black topcoat, but again the surface that resulted wasn't particularly good. I think spraying will work better once I get some equipment to do it. That said, I'll touch up the drivers again later.

Today I tool the drivers to school to quarter them. I know traditionalists will scorn my use of Loctite, but I feel confident that it will work just fine. Yesterday I used Loctite 620 to attach each axle to one driver, letting it cure overnight. I had previously made a pair of aluminum jigs out of round. One end was turned to .500" to fit the crank pin hole, and the other to .875" to match the axle diameter. Putting the axle and attached driver in a v-block on a surface plate, I turned the it so that the top of the axle and the top of the jig were level, using a height gauge as the reference. The axle is then clamped into position on the v-block






The crank pin hole is now horizontal with the axle hole to a quite good level of precision. The second driver has Loctite applied to the axle bore, and with the second jig in place was inserted onto the axle. On this side the jig and axle are aligned vertically with a machinist square, again with a good degree of precision.






The two crank pin holes are thus oriented at 90 degrees to each other (QED). The setup was allowed to cure for a couple of hours, although the Loctite would cure sufficiently to remove from the setup within 15-20 minutes.

To ensure proper spacing between the drivers, I had made a spacer from some aluminum rod that I faced to 7.125". This rod was placed between the backs of the drivers when placing the second driver onto the axle.


----------



## kvom

Still fighting the cold, but the past few days resulted in two partially finished parts.  I bought some more 1/2" CRS, so decided to attempt the eccentric strap for water pump. This has three separate parts, including the rod. The first half of the strap was profiled on the CNC mill.






Then the part is chucked upside down on the Bridgeport, and the support material whittled away with a face mill. I rather like this method of "fixturing" as it results in a good finish on both sides.






The other half of th strap was machined the same way. Then with drilling and tapping, the two halves can be screwed together. I then faced both sides of the combined strap with the face mill to get the sides flat and parallel before going back to the CNC mill. 






The center bore had been left a good 1/8" small when milling the halves, and now with them together the finish diameter can be milled.






Now the fit to the eccentric:






It's a little "tighter" than Kozo seems to like, but I imagine it will wear a bit early on. I drilled the oil holes before milling the bore, so what remains is to mill a slot for the eccentric rod,

I started to mill the rod this morning, but broke 2 carbide endmills trying some new "techniques" and ruining the prepared stock, so to avoid depressing myself further I switched my attention to the front coupler pocket. Rather than soldering together various pieces, I intend to mill it from a single steel block. Starting with a piece of 1/2" square CRS stock, I milled the starting block to external dimensions on the Bridgeport. Here it is posed where the final piece will mount on the front bumper.






The first operation was the radius for the front:






Then side flanges:






There are two pockets yet to be milled plus drilling and some other finishing. I'm not going to drill the hole for the coupler pin until I actually have a coupler to fit.


----------



## kvom

Today I finished up the coupler pocket. Did all the drilling on the Bridgeport - 1/16" corner holes for the main pocket (which may be unnecessary), mounting holes for 8-32 screws in the flanges, and a 5/8" hole in the center pocket for material removal. Then onto the CNC mill to mill out the coupler pocket. I retrospect, this would have been just as easy to do manually.






The bottom pocket and the bottom flange angles were milled on the Bridgeport.






Ready for paint and a coupler for fitting. I can file out the corners if needed.


----------



## kvom

With only an hour or so of shop time today, I contented myself with machining the slot in the eccentric strap where the rod fits. The plan specifies a rather awkward 5/32 width, for which I don't have an endmill. And in any case, milling a deep (.4") slot with a 1/8" endmill is not that easy either. So I decided to first cut the slot with a 1/16" slitting saw, and then widen with with a 1/8" endmill. While the G-Wizard feed&speed calculator gave a reasonable result of 180 RPM and 6 IPM, there was no real counsel on DOC. I ended up cutting repeatedly at .02, which took a while.

Then my cheapo Chinese carbide endmill gave up the ghost after cutting a single pass at .015 DOC and 1 IPM. Luckily my medium priced Chinese endmill did survive to the end of the slot. So far I've broken 3 of the 1/8" 2-flute carbide endmills from Richon tools by barely breathing on them.    While their 1/2" carbide seems OK for roughing work, these small ones are just too fragile for anything.


----------



## kvom

I didn't get a whole lot of shop time over the past few days, but did machine the eccentric rod to go with the strap.






You can see where an overdeep cut with the slitting saw heated up the strap, but that will be painted over. While Kozo uses two screws to attach the rod to the strap, I decided to just use the Loctite 620, which worked well.

I had bought some 2" square CRS a week or two ago, so I decided to start on the tee. i sawed of a chuck about an inch longer than needed, and machined the long sides to 1.875 x 1.625 as per the plans. Squaring the ends with side flutes of a long end ill wasn't a success, as I got a lot of chatter even with a very shallow DOC. I decided to see how it would work on the lathe anfd 4-jaw chuck.






I was a bit nervous with so much sticking out (7" with only 1" jaw length), but a facing cut produced a good result, even if the DOC was about .01". The length is still 3/4" longer than needed; I expect to mill to final length once the cylinders are present to be fitted.

Since the piece is longer than needed, I milled the 4 slots using the center as the datum.






I need to drill two through holes lengthwise for steam supply and exhaust. I'll need to drill these halfway from each end. Given the facing cut on the lathe, I assume I could drill these on the lathe, but it seems easier to drill vertically on the Bridgeport.


----------



## kvom

Yesterday I finished up drilling the steam and exhaust passages in the Tee. Lots of pecking and chip clearing to get 3.5" deep holes. The steam passage is 9/32 and the exhaust is 11/32. Still to do is take 1/4" off each end; the faces need to end up exactly level with the outside of the frame. Then it's milling the 45 degree angles on the ends to fit through the holes in the frame.






Today I made the second support plate and bracket (made the first some time ago, but ran out of material then). Rather than mill the bracket out of square stock, this time I had some angle iron. That said, it wasn't any quicker to make.






I misread the drawing and drilled the top holes 1/16" too close to the edge, so I'll need to account for that when I drill the running boards.

Finally today, I wanted to measure the center to center distance between the two axles, as that will be the distance needed for positioning the bushings in the connecting rods. Not having any accurate hand tools for measuring 12+ inches, I came up with this setup on the mill table.






Then I could use an edge finder and DRO to measure. The plans call for 11", and I measured 11.009 in the center and 11.003/.004 at the sides. I am wondering how much slack is permissible here. I assume that a few thousands clearance in the bushings can accommodate movement as the wheels move about. Perhaps experienced builders can comment.

I also measured the outside frame widths at front and read. At the front where the tee needs to match, I measured 6.548 vs. 6.562 plan, while at the rear it was 6.525.


----------



## kvom

After a long weekend of family obligations, I got into the shop for a few hours each the past couple of days. Yesterday I decided to make the water pump plunger as it should go quick and I had a length of 1/2" 303SS rod available. The turning went quickly as other than getting the correct length, there were only the bevels on each end. I then used a square collet block to drill the cross pin hole, and then only the slot for the eccentric rod was left to do.

My plan was to cut it with the 1/16 slitting saw and then mill to 1/8 width. However, using the 92 RPM in back gear called-for by G-Wizard, the saw stalled without cutting. Adding some RPM was no better. So now I need to try to mill it. Not having much confidence is a 1/8 endmill cutting a deep slot, I decided to first use the hacksaw to make a slit 1/2" deep. This gave a place for swarf to fall. Then I just took .010 deep passes, and widened the slot .01 on each side every .05 of depth. Took quite a while but got there eventually.

Then made the exhaust deflector; rather than turning in one piece, I did the shaft and baseplate separately and joined with loctite.






Finally today turned the bronze O-ring retainer/bushing for the water pump. I modified the OD to 3/4 rather than the scaled .772 in order to be able to ream the matching hole in the pump.






Before deciding to finish the retainer, I had started to want to make the crank pins. Before deciding on the OD of the pins, I thought I'd better see what reamers I have to ream the bushings that go over them. Kozo used .281, which scales to .562. The closest reamer I own is 14mm or .551, so that's what they will be. This gives the ID of the bushings, and the OD needs to match the bores in the side and main rods. Kozo used 9mm for the rods, but not having an 18mm reamer my choices are 16mm (.6299) and .750. I drew the main rods in CAD, and .750 will work. If I use .6299 with a .551 ID, then the wall thickness will be only .04, which seems pretty thin.

I need to draw the side rods in CAD to see how a .75 bore will work with the other dimensions,


----------



## kvom

After some drawing and calculating, I got in the shop to turn the crank pins. Small dia. is .500 to match the holes in the wheels, and .546 to give clearance for the .551 bushing ID.






The locknut was to test the clearance of a threaded side rod pin, as I neglected to bore a place in the back of the wheel for an e-clip
.


----------



## kvom

The past few days I've made a start on the side rods. Since my supply of 1/2" CRS is 3" wide, I decided to just make both at the same time from one piece of stock on the CNC mill. So I cut off a piece 13.5" long, squared the edges, and drilled two pairs of reamed .375 holes 11.004" apart. Then I got a piece of donated CRS 2.375" wide; drilled and reamed matching holes. The "locator" pins which pass through the holes keep the stock from moving as it is machined. I made these pins from drill rod. They are a few thou smaller than the combined thicknesses of the jig plate and stock, through drilled 1/4". 






Now I could mate the stock to the jig and secure it with 4 1/4" screws and nylon locknuts (locking nuts are needed as the vibration from milling can loosen normal nuts.






The jig plate is mounted on the CNC milling vises. I like these two 4" vises vs. a 6" vise as I can hold longer pieces.






The first operation was to rough out the shapes using a 3/4" HSS 2-flute endmill.






Then two additional passes with a 7/16" carbide 4-flute endmill, and I end up with these:






All the rest of the work on these will be manual milling.

I learned quite few things doing these pieces, and making the main rods should go a lot faster. One thing that stands out is that I should make each singly from narrower stock. The necessity to rough out the "valley" between the two means a slot cut, and that needs a much slower feed rate. Machining a single from the outside in can be done considerably faster with deeper cuts.

Work remaining is to drilling/reaming the holes for the bushing, counterboring one hole in each for the retainer pin, drilling the oiler holes, and narrowing the "neck". The pieces are also .08 too thick, so that will be faced off to spec.


----------



## kvom

Yesterday and today more work on the side rods. I needed to accurately enlarge the 4 crank pin holes to .75" (i.e., keeping the 11.004 hole center separation). After mounting the ron the vise, the I used a locator pin plus the coaxial centering gadget to center the spindle over the hole.






With the table locked, I enlarged the hole by drilling by 1/16ths up to 11/16.






Then a further 1/32 via the boring head (This will correct any wandering of the hole caused by the drills).






Finally the 3/4 reamer.






Repeat 4 times.

Then it was on to the lathe to turn phosphor bronze bushings for the rods, plus two for the large end of the main rod. The bushings were reamed to 1/2", and will be enlarged to fit the crank pins once they have been loctited to the rods. For now it's just a push fit.


----------



## kvom

Today I finished profiling the sides of the side rods and loctited the bushings. Rather than the side flutes of a 1/4" endmill for the radii, I used the end of a 1/4" ball mill. This saved making the jig that Kozo suggests.






Next I'll ream/bore the bushings and finally see if how they work mounted to the drivers.

Still to do is drilling and tapping for oil cups on the ends. That's wait on a make/buy decision on the oil cups.


----------



## kvom

A "milestone" today. I finished drilling/reaming the side rod bushings and mounted the rods and crank pins onto the drivers. *No binding, smooth as silk.* So the measurements and quartering look good. That's a load off.






I plan to do the main rods and reverse cranks next, so that I can trim the crank pins to length. I'll also be able then to measure the centerline separationof the main rods, and move on to the cylinders.


----------



## 1hand

Looks Great!

Matt


----------



## b.lindsey

Kvom, I have been watching this one from the beginning and I admire you loco guys for undertaking such intricate projects. Its looking so good thus far and I definitely look forward to seeing more. 

Bill


----------



## kvom

Matt and Bill (and any other silent witnesses), thanks for following along. So far nothing has been particularly difficult to make; it's just that the goal is a lot further away than for most models.

Yesterday I started on the return crank, a part that attaches to the rear crankpin and along with the motion of the crosshead creates the timing for the valve. After cutting and squaring pieces of 1.5x.5' steel and drilling the two holes, I mounted them in the CNC mill vise to mill the outer profile.







I used soft jaws here as I was milling quite close (leaving .10) and hate to mill my hard jaws. I also wanted to use the soft jaws for the last step.

Now to the Bridgeport to mill the relief (needed to clear an e-clip for the attached part). The radius cut was done with a 1/4" ball end mill, taking lots of small cuts.






Next, I milled the clamping slots using a 1/8" endmill on the Bridgeport, taking only .015 DOC each pass and blowing chips with air all the while. Tedious, but the endmill survived. Per plan, the slot would be 1/16 but it doesn't matter in this case.






Next, I drilled and tapped the clamp screws using 8-32x1"






Now it remained only to remove the square backing that remains. Since the part is not suitable for regular cvise clamping, I milled a pocket in the CNC vise's softjaws, enabling the parts to be held securely. Then used the facemill.






Mounted on the crank pin for a poser shot:


----------



## b.lindsey

Kvom, still looking good and I love the "poser" shot too. Steam and IC engines are all fascinating but something about a loco coming to life is extra special! I noticed the coax indicator...you gotta love those...just wish I could find one in a smaller size for benchtop equipment. I also noticed in your profile that you are from Cumming GA. I grew up in Atlanta and as a kid we would spend most summer weekends in the north Georgia mountains camping and often came through your neck of the woods. 

Looking forward to more as you progress.

Bill


----------



## Deanofid

Yeah, I like that 'poser' shot too. Sure looking good!

Dean


----------



## xo18thfa

Gorgeous work kvom. The big day should be coming soon when you can push it down a track.


----------



## kvom

The past three days were spent making the main rods, with shop time interspersed with real life.

I had cut and faced the 1/2" CRS stock a while back, so the first tasks were to drill mounting holes in both the stock pieces and the jig plate, similar to the side rods. Then it was on to the CNC mill to make the outer profile.






Then it manual milling for all the rest. First, face mill to remove the bottom remainder.






I diverged from the plans a bit, as Kozo's dimensions result in a 1.4 degree included angle between the top and bottom of the shafts. Since I was going to use angle bars to finish the angles and have only integer angles, I redrew it to give a 2 degree shaft taper. In order to be able to mount the shafts in the milling vise, the CNC profile has the taper on both ends and leaves it square in the center.

The next operation was to drill/bore/ream the bearing holes, .75" and .5".






The next operation was to mill the shaft to a .25" thickness.






Next mill the side radii using a 1/4" ball end mill.






Next finish the first taper using a 1 degree angle bar for setup.






For the opposite side I needed a 2 degree bar.






Poser shot:


----------



## kvom

The past two shop sessions were spent making the main parts of the yokes. These psrts are attached to a tie plate and in turn the frame. In turn 3 brackets for the valve gear linkage plus the crosshead guides attach to each yoke, and the radius rod passes through the slot. I decided to make these from brass for a couple of reasons. First, I had a 6' length of 4x1/4" 360 brass, and second because some silver soldering is needed and I am more confident in soldering brass than steel.

The first operation on the mill was to drill all of the clearance holes for the 8-32 mounting screws. I also cut out one corner on the bandsaw which would otherwise be milled away. The screw holes provide mounts for an aluminum jig plate that I also drilled.






Now the CNC mill carved out the outer profile plus the slot:






After deburring, they're ready for soldering on a bar on the top, providing a support for the walk boards, and two cubes on the bottom that will be the attachment points for the crosshead guides.


----------



## bearcar1

Breathtaking it is. I sit here shaking my head and saying to myself, "self, you too could do that, it's easy, I tell you... easy." to which my usual reply is "yeah.... right" and then the wife says "what did you say".......... grumble, grumble, easy I told you. And of course she doesn't understand. ???


BC1
Jim


----------



## kvom

Most of the machined parts in this engine are not that hard. Kozo likes to put a lot of radii on parts that would work without them but wouldn't look as good. These yokes would be one of the harder parts to make manually as the two curves in the profile do not have centers that are easy to locate on the stock itself. His drawing, in fact, doesn't help much in that respect either, and I needed to use a CAD option to draw the circles. The smaller circle has a given radius and passes through two points. The larger has a given radius and is tangent to a line and the smaller circle. Of course, once the drawing is done that way the centers are defined.

Were I doing this manually, I would do them one of two ways:

1) rotary table
2) Print the drawing full scale, cut out the profile, and trace it on the stock. Milling and filing could give a perfectly acceptable result.

I think the hardest part about this project is the sheer number of parts to be made, and the possibility of losing interest as the project drags on. I've been told that the average time to completion of a builder's first loco is 9 years! My target is a chassis running on air by the end of this year, and under steam by the end of 2012.


----------



## kvom

After a couple of days devoted to working on the Jeep, I finally got back to the shop to continue on the yokes. The plans call for a 1/4" thick piece to be silver-soldered to the top edge forming a platform to which the walkboards are screwed. Unfortunately, when I tried to SS them, I was not able to get the pieces hot enough for the solder to melt. It seems that the brass just conducts the heat away too fast (I was using MAPP gas torch). So my alternative was to screw the piece to the yoke with 6-32 screws, which will be loctited. Kozo has the top mounting screws tapped into the soldered joint, but with my screw attachment I don't like that idea. So I plan to mill two holes in the joint and loctite drill rod pieces containing threaded holes instead.






On another front, I ordered the cylinder castings from Friend's Models, and they arrived yesterday.






Each chunk of cast iron weighs around 12 pounds! I redrew Kozo's plans in CAD to scale up all the measurements, and it seems that there is plenty of extra material in all dimensions. I've got a decent idea of a machining plan, but want to get it all written down and reviewed before cutting any metal.


----------



## kvom

Made a start on one of the cylinder castings today. It seems likely that these castings were made originally for a larger engine, as the dimensions are quite "excessive" in every direction. That's not a problem, but there's that much more material to machine away and thus more time. I first machined the steam chest and frame faces flat and square to each other in order for to of the jaws on the lathe chuck to have full contact. I then machined one of the ends flat in order to set square to the face of the chuck.

My largest boring bar can only go 4.25" deep, and the casting was about 4.6" in length. So it was necessary to mill both ends down until the length was about 4.1". The final length is 3-7/8, so there's a lot to be removed.

Then it was time to mount in the 4-jaw and center on the bore in the casting. It's not necessary to be to super-exact as the cast bore is somewhat irregular and there's lots of material available to adjust to the centerline once bored. I got it aligned to within 1/8" all around.

Luckily my chuck has a 2" center hole, so I could bore out to the target 1.75" diameter without worrying about boring into the chuck body. After multiple slow passes I crept up to the target diameter.






The casting is quite unbalanced, so I needed to keep the RPMs down to about 350 to keep the lathe from shaking. Once bored, I turned outer round surface down to it's target diameter, then faced .25" deep to square the sides of the faces. This is an interrupted cut so I took it quite slow.






Once I removed the casting from the chuck, I stamped the face to identify it as the rear. Since it is as close to square to the bore as possible with the lathe, mounting the rear cover and piston opening there will be preferred.

That's as far as I got today. There's lots of machining to do on these, so it could take a while.


----------



## kvom

Today I continued to whittle away at the cylinder casting. First, I machined the front face to bring the piece to the overall final length, then face milled the steam and frame faces down. I left the frame face .025" higher to provide for possible fitment later.






Next I mounted on the CNC mill with the front facing up and used the coax indicator to center on the bore. Then milled to yield this:






The final work of the day was drilling the mounting holes for the front cover.






I still need to figure how to mill the outer curved profile. Kozo's lathe method would be impractical given the amount of CI still to be removed.


----------



## Sparticusrye

If your going to be using the mill to take the outside down to size then I would recommend making an arbor to go through the bore with a slight taper or a two piece arbor that is threaded to clamp the piece. Then mount it in an indexing head with tailstock support and mill it down rotating a few degrees after each cut until its to size. I am sure there are other ways but that would be my choice.

James


----------



## kvom

That's one thought I had; I have a HV rotab, but no tailstock; it would likely work OK.

My current plan is to use the CNC mill mounted as in the photo above. I'll have to turn it over to do in two passes. I'll try it out leaving a large clearance to see how close I can get between the two. If the edges meet cleanly then I'll take it to final dimension.


----------



## Sparticusrye

As long as you take your time and double check everything you should be able to get it close. Then, with a little filing and sanding, you would be able to remove any line caused by small missalignments.

I'll be following your progress as I am planning on starting a Kozo project sometime in the, hopefully, near future. I'm just not sure if I want to build the A3 or a Shay.

James


----------



## kvom

I decided to CNC the outer profile, and up to the end it went well. The first step was a roughing pass leaving .05 " of material for the finish pass. Each pass needs to be done twice (with the profile mirrored) because of the total depth. Here's the end of the first roughing pass:






Then the first finish pass:






After that the setup was good for drilling the rear cover mouting holes.

Then on the final finish pass, the mill decided to have a mind of its own and cut into the face a bit before I could hit the stop.  






That blemish is not in a critical area and won't be seen with the front cover on as it will be next to the frame, so I'm going to continue on with it rather than throw away a $60 casting and a lot of shop time. Still pi$$ed about it though.

Having gone through the steps to this point, I have concluded that for #2 I can CNC the entire profile and save a lot of hand cranking on the Bridgeport. We'll see. And given that possibility, it will be just as easy to machine the cylinder from barstock as from the casting.


----------



## imagineering

kvom  said:
			
		

>




A good photo to post here;
http://www.homemodelenginemachinist.com/index.php?topic=14032.msg144465#msg144465

.


----------



## kvom

I weighed the machined cylinder at about 5 pounds, compared with 12 when I started. So there's 7 pounds of CI dust lying about the shop somewhere, and another 7 to go.


----------



## kvom

Some progress over the past few days since the last post. I bored/turned/milled the left hand cylinder out of its casting, and drilled the holes for the cylinder heads, so it was at the same stage of completion as the right hand. The next stage was drilling the mounting holes on the frame sides. Here my X zero is the center of the bore, the Y zero is midway between the ends. Here's how I set it up:






The parallel sits on the top of the vise jaws while the cylinder sits gently on the parallel. A square was used against the steam chest face to square the Z axis. Now an edge finder on either side of the parallel allows the centerline to be found. The hole pattern center is offset from the centerline to the outside, and the tee mounting holes are towards the front. Rather than mirroring the drawing and regenerating the g-code, I used the scale feature of mach3 to mirror the X axis. Thus I could use the same program for both cylinders. That's the first time I've used that feature. The holes for the steam admission and exhaust will be done manually on the Bridgeport. I center drilled to mark the locations.






Now the remaining milling is the steam ports and passages, something that can be a bit nerve-wracking, since a screwup is unlikely to be fixable. I decided to defer that task to a future date. In the meantime, I spent this morning making the steam chest covers on the CNC mill. These would be pretty easy manually, and probably as fast for one, but I wanted to have the rounded corners as Kozo specifies. The first cover tool a couple of hours total getting everything set up and checked out before cutting metal; the second took 30 minutes. I drilled the holes and then milled the profile .26" deep in some .50 CRS, then face milled the bottom on the Bridgeport. The profile was milled .02 oversize. I plan to do a finish pass with the steam chest, cover, and cylinder screwed together so that all have the same.






One of our club members suggests an extra pair of mounting holes between the steam chest and the cylinder using countersunk screws. These would allow the cover to be removed without the steam chest itself moving. This sounds like a good idea. I'll wait to finish the cylinders as drawn before figuring out a cood place for these holes.


----------



## imagineering

kvom  said:
			
		

> One of our club members suggests an extra pair of mounting holes between the steam chest and the cylinder using countersunk screws. These would allow the cover to be removed without the steam chest itself moving. This sounds like a good idea. I'll wait to finish the cylinders as drawn before figuring out a cood place for these holes.



I would also suggest Drilling and Tapping two extra Holes in the Cover, one at each end. This allows two Bolts/Screws to be inserted in these Threads to jack the Cover off and break the Gasket/Sealer to allow removal later on. It saves having to hit the Cover with a Softface Hammer to try and break the Seal.

Murray.


----------



## slkride

that little divot on the cly sure sucks.pulled one similar a few weeks ago J B Weld to the rescue, you might give it a try since it's gonna be hid and not in a critical location.

                                        Tom


----------



## kvom

I'll have the jack screw in the cover; waiting to do the steam chest before deciding on size/position.


----------



## Sparticusrye

Cyclinders are looking great. I definately like the idea of using castings over Kozo's way of using a large chunk of brass.

James


----------



## kvom

Kozo specifies bronze rather than brass, but CI would also work on the 3/4 scale version. Based on working with these castings, I think starting with 4" round CI would be just as easy to machine and would be about half the cost for raw material. That said, the casting quality is good and I have no complaints.


----------



## kvom

Today it was time to drill and mill the steam chest face of the cylinders. In addition to the 8 8-32 holes for attaching the steam chest and cover, I also drilled some holes to clean material out of the steam ports. This way the 1/8" endmill has less work to do.







Setting up, testing, and running took a couple of hours of shop time for the first one. Then the second took just about an hour.






Now just need to drill the passages and tap 26+ holes on each cylinder.


----------



## kvom

Another session drilling steam passages this morning and afternoon. The exhaust and inlet holes went well, as seen here:






I was a bit nervous drilling at first, but I'd triple checked everything. I was glad to feel the drill bits ending up where they are supposed to.

Later this evening I drilled the first pair of steam admission holes. One came out a bit high in the port, so I need to figure out if it can be enlarged any. I drilled these .125 to start, but in theory they should be .196.


----------



## kvom

With some expert advice over at HSM, I managed to finish the admission holes successfully. The main changes I did were using a 26 degree vs. 28 drilling angle, and starting the hole with an endmill as a drill guide. Did successive drilling with 1/8, 5/32, and finally 3/16 using collets vs. a drill chuck.






So now just a lot of holes to tap. Did I ever mention I hate tapping?


----------



## kvom

Worked on the valves the past couple of times in the shop. I started with two pieces of 1.625" diameter phosphor bronze rod that I faced to final length of 1.32". For scaling Kozo's drawing a minimum diameter of 1.25" would work. 






Next, I used a face mill on the Bridgeport to square the pieces to final width and height. Kozo mills andles on all 4 sides to fit the minimum diameter rod, but in this case I could have used the oblongs as is.






Nevertheless, I proceeded to mill the 45 degree angles on 3 sides. This does leave more volume in the steam chest for steam, so perhaps a good thing.






The valve pocket in the bottom I CNC-milled using a 1/4" endmill.






For the lengthwise slot that contains the end of the valve spindle, I notices that Kozo used a 2-56 thread and makes the slot .001 wider than the major diameter. I will use a 10-32 thread (diameter .19) so milled with a 3/16 endmill (.188). The resulting slot is wide enough to hold a 10-32 screw snugly. The cross slot can be any width as long as the nut fits securely. I used a 5/32 endmill and will machine the nut to match.


----------



## kvom

Today being "take your son/daughter to work day", my 14 y/0 was working with me in the shop today. Our project was the valve spindle yokes, pg. 103 in Kozo's book.

After rough cutting some 1/2" thick CRS on the bandsaw, Melinda was cranking the handles to square the pieces on the Bridgeport.






We then ran the CNC mill to create the profile, as well as center drill for the holes.






Back to the Bridgeport to mill the center gap of the yoke, then drill and ream the through holes:






After drilling the hole to mount the valve spindle, she tapped them 1/4-20.






The finished results, after about 3 hours:






She said she liked running the machines, but all the measuring and setup was a bit tedious.


----------



## steamin

Thank you for sharing. It reminds me of when My daughter use to play in my home shop. After many years I have her back only this time she has a corner with her art supplies to do her free lance graphic arts designs. Isn't Kozo outstanding ?


----------



## kvom

Having taken 2 weeks off for NAMES and then some minor surgery, I was eager to get back to work on the A3.

The first thing was tapping the 24 8-32 mounting holes for the cylinder heads. This went quicker than I expected as CI taps very nicely. I used the mill/DRO to position the tap vertically and start the first couple of threads, then finished with a tap wrench as usual.

I bought a piece of 3.5" brass rod at NAMES that I thought would make up the front cylinder heads. It was about 1.5" long but the ends weren't square. I mounted in the lathe, squared the faces, and then faced the spigots that fit into the cylinder bore on both ends. The resulting piece was now 1.32" long. Now I needed to split this into 2 thin discs. Starting with a 1/16" parting tool, it became obvious that this wasn't going to work, as the tool was flexing. I switched to a 1/8" blade and slowly cut using back gear and ~150rpm. When the diameter was down to 1", I cut the rest with a hacksaw.

Here's the result. The rest of the machining will be done on the CNC mill.






I also bought a piece of 4" diameter brass rod for the rear cylinder covers. I'm hoping it's long enough to part on the bandsaw.

I also


----------



## kvom

Recovering from surgery, I'm limited in what I can do in the shop (no lifting). So I have a backlog of stuff waiting until I can go full speed. Today I finished tapping all the holes on the cylinders: 8-32 for the steam chest and 10-32 for the tee/frame.

I also got my shipment in from Speedy Metals. A length of CI bar for making the steam chests, and two lengths of SS416 rod for the piston and valve rods, so those are now on the todo list.

I also tried out the 6-7 micrometer I picked up at NAMES for measuring the outer frame width vs. the length of the tee. I have about 3/8 to take off the tee so that it matches the frame. That way the cylinders, frame, and tee all fit together flush on both sides.


----------



## kvom

I was able to trim the tee so that it and the cylinders will fit flush to the outside of the frames. Then it was on to work on the steam chests. While these are relatively simple. I still put in a lot of hours over the past three days.

I had a 13" bar of 3.25x1.5 CI, enough for the two steam chests and a third if I screw up. After sawing into thirds and squaring each piece, I had a couple of these.






The bars are advertised to finish 1/4" less than the size. Since the chests are 2-3/16" wide, I would not have had much allowance with a 2-1/4 width. However, that meant a lot of CI turned into swarf.

Next, used the CNC mill to drill the mounting holes and machine the outer profile. I added two additional holes which will attach to the cylinders but be countersunk and not go through the cover. These will allow the cover to be removed without the steam chest moving. The larger hole in the center is just to allow milling the center pocket with a non-center-cutting endmill.











Next the bottom 1/4" is milled off using the bridgeport, leaving the steam chest 1" thick. The slide valve does appear to fit.






Rather than turn the spigot on the lathe, I used the CNC mill to do it faster.






Finally today, put the tee and cylinders together on the frame. I had to trim the ends of the tee a bit as it's a close fit in the frame pocket.






Still to do on the steam chests:

1) Bore a pocket in the spigot for the bushing (yet to be made) and o-ring, then the threaded hole for the bushing retaining screw.

2) Drill the hole for the valve spindle; I will do this with the bushing in place so that all is concentric.

3) Bore the passage in the inner wall to expose the steam admission port in the cylinder.

4) Countersink the two extra mounting holes


----------



## kvom

I spent the morning turning the valve spindles (fig 17-6, p. 103). Material is .25" 416 stainless rod. One end is threaded 1/4-20 to match the yokes my daughter helped make, and the other 10-32 matching the width of the slots in the valve.

Then it was fairly quick to countersink the two extra holes in the steam chest for 8-32 SHCS, using a 5/16 endmill.

Then I started work on the steam chest bore. The design here, as with the piston rod and axle pump plunger, is to seal the spindle with a Viton O-ring and guide the rod with a bronze bushing, which also acts to retain the o-ring within the steam chest spigot. For the valve, the o-ring is a size 2-010. Using Kozo's allowances on the 3/4 scale plan, I computed that the bore for the bushing needs to be .382 in diameter. I happened to have a .380 reamer acquired in an auction lot at a closed shop, so hopefully that will be close enough.

So the machine ops for the spigot, after centering on the Bridgeport, were:

1) Through drill a clearance hole. The closest drill I had is an F (.257)
2) Machine a flat hole .432" deep using a .375 endmill
3) Ream with the .380 reamer

Here's where I ended the day on the first chest. Once the bushing are made, I will drill/ream the .250" through hole with the bushing in place in the chest. It's not as critical to be concentric since the valve has "wiggle room", but for the piston rod I will need the bushing's hole to be dead nuts with the cylinder bore. I plan to use a similar technique there,


----------



## Maryak

Kvom,

Coming along quite nicely, there are such a lot of parts in a steam loco. :bow:

Best Regards
Bob


----------



## stevehuckss396

Great pics! It's really starting to look like something.


----------



## kvom

Yes, lots of parts. Like eating an elephant, one bite at a time.

Today I just had a few hours after lunch to work, so I finished all the machining remaining on the steam chests, and decided to start on the piston rods. Material is .375" 416 SS, which machines quite nicely. I single pointed the 5/16-24 threads to about 80%, then finished with a die. I still need to drill and ream the cross pin hole and cut the slots on the ends, used for adjusting the piston travel during tuning.


----------



## ShedBoy

That looks great! A loco takes dedication which you seem to have. Fantasics pics too keep them coming.


----------



## kvom

The past couple of shop sessions were dedicated to finishing the front cylinder heads. Previously I had turned the mating surfaces and bore spigot from a piece of 3" brass round. To hold these discs, I now needed to make a new set of vise soft jaws. 

I made two sets from a 6' bar of 1"x2" aluminum ordered from Enco. This bar costs about $11/foot shipped, so for 6" jaws that's $11/pair/ I could have ordered 10 pairs already made from "monsterjaws" on eBay for $113 shipped. The reason I decided to go this route was that I can also make jaws for my 4" vises from the same bar. In any case, it took about 90 minutes to cut, mill, drill, and countersink 4 jaws. These are a bit larger than the standard hard jaws as can be seen here:






Next I milled a circular pocket in the jaws to hold a piece of round aluminum, then drilled and tapped 8-32 holes to match the pattern for the heads.






Next I milled a 3" pocket in the jaws to hold the heads so that I could face the outer side.






Next, reverse the head in the pocket and use the coax indicator to center on the bore spigot.






Now I can accurately drill the 8-32 clearance holes centered on the spigot.






Now the head can be reversed and the outer spigot milled.






Finally, screw the head to the fixture and mill the outer edge to finish diameter.






Mounted on the cylinders; like Jesse Banning's versions, I plan to leave the heads exposed and not machine the covers. I have ordered some model-scale hex cap screws to attach the heads, as well as the steam chests.


----------



## kvom

For a short shop session today, I made a start on the rear cylinder heads. These start as a 4" diameter drop of brass about 4" long that I bought at NAMES. I tried cutting it in two with the bandsaw, but couldn't get the blade to start straight, so another strategy was needed. After face milling both sides flat, I used the CNC mill to reduce the diameter to 3.5" for a length of 1". This meant that I could chuck it in the lathe.







Now I could turn most of the rest down to 3.5", then face and turn the bore spigot for the first cylinder.






Then I needed to part off the first one. Using a 1/8" parting blade and the lathe in back gear at 200 rpm, I was able to get a pretty good cut. I started out with only 1/2" of blade exposed in the holder, and then successively extended it bit by bit. Once the outer slice started to wobble, I could just break it off by hand. Then I did machined the face and spigot for the second cylinder without needed to rechuck.






Since these are now 3.5" in diameter, I can use the same pockets in the soft jaws as for the front heads to continue machining.


----------



## kvom

The next ops on the rear heads were to drill the mounting holes and then mill the final flange diameter.






Now I needed new pockets on the soft jaws.






Now the two spigots on the rear side of the head could be milled.






Then the through hole was drilled and reamed .380, and the bushing pocket was milled: .507 diameter, .782 deep using a 3/8 endmill.






There are still some ops needed on these parts for mounting the crosshead guides, but that will wait until I know the piston will move properly. So the next tasks will be to machine the bushings to fit the pocket, and then make the pistons. I already have the rings, so once it's all together will be the moment of truth.


----------



## kvom

The past few shop sessions were for making the pistons, parts that seem pretty simple looking at the plans but which took me a lot of time to realize. I started with a piece of 2.5" diameter CI rod left over from a previous project. There was "just" enough there to make the 6 pieces needed for two pistons, so some rechucking at the lathe was necessary.

First I turned the diameter down to the 1.745" called for in the plans, then drilled and reamed through.






After much difficulty and breaking my 1/16" parting tool twice, I got the pieces roughed out.






Lots of milling, drilling, reaming, counterboring and tapping later, the result:






I loctited the large pieces to the piston rods, then assembled using 5-40 screws. Now I could chuck the rod in a collet on the lathe and take a small turning cut to true all the diameters.






Then I turned the bushings from phosphor bronze and did a quick assembly with the cylinders.






The good news is that both pistons slide smoothly within the cylinder bore, although neither the rings nor the screws for the heads are in place. I have tested that the rings do fit well in the bore. However, the piston body needs enough clearance to account for expansion when running. This is needed since the piston will expand faster than the cylinder when steam is introduced. Kozo's plans call for .005" difference in the piston and bore diameters; based on the design however, I think the clearance can be a bit larger than that without harm.

While the green loctite 620 should be sufficient to fix the piston on its rod, I will also add the pin that Kozo specifies for extra security.


----------



## kvom

Some small but tedious progress today. Using the cylinders as jigs to hold the heads, I milled the flats where the crosshead guides will attach.






I think this is a better/quicker method than that used by Kozo for the smaller version. Then I drilled and tapped the 5-40 holes for attaching the guides, as well as the hole for the set screw that retains the bushing.






Finally, used a piece of aluminum round to turn the "piston insertion tool" show on fig. 5-8 on pg. 225. This jig has a tapered bore that compresses the rings as the piston is pushed through into the cylinder. It's almost impossible to insert the piston and rings into the cylinder without this (although I tried hard).






Following photo is a test fit of the steam chest/cylinder/cover using the model scale screws from AMS. I plan to leave these exposed and not fabricate the outer covers. The same type of screw will be used for the heads.


----------



## kvom

Back at it after some family vacation time.

I finished the machining of all the spring hangers from pg. 210. 






I made this harder than it needed to be. If I can remember not to try to cut slots with a 4-flute endmill and not to reply on cheap Chinese 1/8" carbide endmills for anything, things might go better in the future.

Still to do is round the edges that go through the spring slots, heat and twist two of the hangers 90 degrees, and turn all of the pins that hold it all together.

I also need to remake the spring bands (pg. 209). I find that with the springs cambered they don't fit through the opening. Rather than as drawn, I'm going to make the tops open with a cap.


----------



## stevehuckss396

I don't usually say much here but I am really enjoying watching this build. Thanks for posting.


----------



## Sparticusrye

Some excellent looking parts and good progress. Its got me itching to get started on a Kozo Shay.


----------



## Lesmo

This is a major project, I have read only to the end of page 5 to date so if its not been asked before, have you a rough idea how long it takes to complete something like this.
Not that I am thinking of following in your footsteps, its a just a little beyond my skill level,           like about 3000 light years or so. Will be following to the finish. 

Les  :bow:


----------



## kvom

I started this right after Thanksgiving last year. I have a goal of getting "chassis on air" state by the end of this year, and having a steamable locomotive in another year. Once I get the springing sorted out, I need mainly to finish the valve gear and crossheads to be able to test on air.

I am not making the boiler and smokebox myself. Being retired, I expect to be able to spend an average of 10 hours or more per week of shop time. Having a CNC mill helps with parts such as those in the last picture. Without a full size mill and lathe it wouldn't be possible to build it at this scale. I also have the resources of some very experienced builders at my club to draw upon for advice.

I have not decided whether I will make the A3-style slantback tender or buy a fiberglass tender tank. In either case I plan to purchase the tender trucks from Tom Bee with air brakes. I also plan to install an injector in addition to the axle pump, and thus may skip the tender hand pump. I will also purchase the couplers, ball valves, and possibly the handrail stand castings. 

I will also decide at some point whether to purchase a pre-made lubricator and/or whistle. I will likely install automatic cylinder cocks at first, then fabricate the finicky manual parts at the end.

My current estimate is that I will spend ~$4-5K on materials, with more than half going to pay for the boiler and smokebox. The 3/4" scale would be much cheaper to build, although probably not much faster.


----------



## ChooChooMike

Current boiler prices for say a Gene Allen 1-1/2" Mogul run around $3300-$3500 from one of the boiler shops. Just a point of reference.

Mike


----------



## kvom

I'm having Jesse Banning make mine. He's already made a couple of A3 boilers.


----------



## kvom

With the hangers machined, I now needed only the gibs (spring retainers) to make before trial fitting. While the gibs are pretty simple, I find making them a bit tedious as they are small. 






Both the gibs and hangers needed to have rounded edges to fit through the slots milled in the spring bands. It would have been better to have made the slots longer than per plan, as that way the rounding wouldn't be necessary. As it was, I held the parts with a vise-grip and worked on them via the grinding wheel. Not pretty, but it works. The hangers that attach to the equalizer beam needed to be twisted 90 degrees. I clamped them in the bench vise, heated with a MAPP gas torch, and twisted with a large wrench.

Since I haven't made any of the pins that hold it all together, I just did a trial fit using screws.






I haven't put any camber into the spring leafs as yet. With just the frame weight, the flat springs support the axles with about 1/4" of up travel remaining. With the boiler/water and everything else there's about another 100 pounds left to support, so I need to put that amount of weight on and add spring camber to suit. The ideal height should have the cylinder centerline level with the axle centers. The spring bands won't get tops until I know how much camber I need.


----------



## zeeprogrammer

Oh happy me. Very glad to see this thread again.
I have the book. I have the dream.
I need more...but this thread helps a lot.


----------



## kvom

Today was my first experience with e-clips, which Kozo uses extensively to retain pins. A majority of the pins used in the spring and brake rigging are 5/32" diameter. Unfortunately my 5C collet set is by 16ths, so I started with the few pins in the spring setup that are 3/16". The groove for the clips is spec'ed at .029 wide; I had a grooving tool that I ground for cutting cylinder fins on the Liney Halo, and it turns out that this works well. My "test" pin connects the brake equalizer with the cross member via two short hangers.






There are about 2 dozen 5/32 pins to do, and only the rubberflex chuck will hold that diameter. I'm going to order a 5/32 5C collet since I want to cut the groove close to the chuck face. In retrospect, I think almost all of these pins could be made with 3/16 drill rod.


----------



## ShedBoy

Always a pleasure to see progress on this thread. 

Brock


----------



## kvom

The order from Enco came yesterday so I now have a 5/32 5C collet for making the rest of the spring/brake pins. I also got two sheets of acrylic and a gallon of coolant, so I want to finish setting up the coolant pump and shield before using the CNC mill again. Once that's done, the next parts to be milled will be the crossheads.

Yesterday I visited the local steelyard and picked up this chuck of CRS (1x2.5x6) from which two crossheads will be milled together.






I milled off the torch slag with a roughing endmill, then cleaned up 5 sides with a face mill.


----------



## Rayanth

Buried under all that rust is a beautiful piece of metal!

Buried under all that metal is the part you want to make ;D

- Ryan


----------



## kvom

Doing some "experiments" with a length of DOM tube that might work out as the smokestack.

I don't have a steady rest for the lathe, nor a bull live center, so this is my substitute. I took a piece of 2" aluminun, turned a 60-degree taper one end and center drilled the other. So it supports the tube for external turning.

I don't know if I can turn the internal taper with the end unsupported, however.






In any case, the smokestack won't be needed for quite some time.


----------



## kvom

Over the weekend I finished up all the e-clip pins that hold the spring hangers and brake levers together:











14 pins for springs and 20 for brakes.

There are a number of similar ones still to do for the valve and reverse gear.


----------



## kvom

We had workers all morning tearing up half the kitchen floor wood (refrigerator leaked), so only a short time in the shop today.

I fit together the bits of the brake system that use pins and e-clips to test for fit (pg. 213 in Kozo book). I need to remake one pin that's a bit short.






The two links that connect to the break beam are probably a bit too tight fitting, even with some grinding and filing. I need to get the return springs to see if they will be strong enough or whether I need to make the fit looser. I was able to verify that the brake beam length is good so that I can machine the e-clip grooves in it next session.


----------



## kvom

After remaking the two bad pins and grooving the brake bar, I found the SS springs needed for the brake system at McMaster-Carr, so ordered them. Now, it's time for brake shoes. I had read that Dave Sciavi has used aluminum for loco brake shoes, so I'm trying that first. The shoes require three setups, two on CNC and the final on the Bridgeport. Here's my experiment after op 1:







While the profiling is straightforward, train wheel treads are beveled 3 degrees. I approximated this by cutting tiny "ledges" at .025" separation. I had neglected to realize that this gives the larger radius at the top (i.e, top is inner side), so that the top needs the relief for the wheel flange, and as well the cheek cut needs to be 1/8" deeper. In any case, both the angle and radius of the face are good fits to my drivers, so fixing this one and making 3 more is straightforward.


----------



## kustomkb

Real nice work K. I am enjoying following your progress.


----------



## b.lindsey

I hadn't checked in for a while K, but the progress is really amazing. Top notch workmanship and wonderful pictures also. Once you have the chassis running on air I do hope you will post a video too.

Bill


----------



## kvom

Thanks to all who are following along. My goal is to have something that works first, and looks pretty second.

I got the return springs delivered this afternoon and tried a quick fit. There are a couple of problems here:











I think that having the spring off center will retract the brake shoes unevenly. So turning the brake beam end smaller to fit the spring's loop should bring the spring onto the centerline. Whether having the spring inclined side to side has an effect remains to be seen. To correct that I'd need to grind the head of the level link to clear the spring coil.


----------



## kvom

After revamping the CNC code, I machined 4 brakes shoes from 6061:






The next ops are on the Bridgeport milling a slot for the brake lever and drilling a hole for the spring. I used angle bars to set the shoe in the vise canted 22 degrees. A protractor would have been a bit easier.






Hopefully I can finish the other 3 next time; milling deep slots with a 1/8" endmill is nerve-wracking.


----------



## steamer

Looking Good Kvom!

Dave


----------



## kvom

Today I finished the other 3 brake shoes, and worked on the assembly. I solved the spring position problem by turning a groove in the brake beam to retain the end of the spring, giving clearance to both the beam and levers. Here's what I got with one of the shoes attached:






I am not totally sure how best to assemble these components with the drivers and frames, so I'll wait to pin the shoes until I do a trial assembly.

A friend lent me a Tom Bee coupler until my order shows up, so I wanted to fit it to my coupler pocket. This meant milling 3 sides of the shank. I'll finish milling the end radius and then check for angle movement of the coupler. Once I'm happy with the final shaft dimensions, I'll cut it short and mill the final length.






The coupler is larger than Kozo's scaled-up version (2" high vs. 1-1/2), so it may look a little big for the engine, but as this isn't a museum quality build I'll live with it.

If the brakes fit properly, I plan to assemble with the springs and take it out to the RR to see how it tracks next week.


----------



## stevehuckss396

Don't forget to get a few shots of it sitting on the tracks!!!


----------



## zeeprogrammer

Looks fantastic kvom.


----------



## kvom

Today I assembled the shoes and brake mechanism, then started to re-assemble the frame and drivers. Assuming that I'd be able to do the track test this week, I put small pieces of gauze into the pockets of the axle boxes and oiled them with way oil. I need to think up a good way to oil the axle boxes as unscrewing the two halves of each will be hard to do when the engine is complete.

With the frame and drivers upside down, it was straightforward to attach the complete brake assemly to the frame between the drivers. Initially the position of the shoes relative to the drivers looked good, and while there was some friction, the wheels and axles could turn.






However, when I set the frame upright and pressed down on the brake beam, the wheels and shoes locked up tight and would not release. This seems to be the issue:






The inner edge of the brake jams into the inner radius of the wheel profile. I think the solution is to reduce mill a larger relief for the wheel flange. The brake surface seems to align very well with the wheel circumference with about 1/8" clearance all around. I'll generate the necessary CNC code tonight and remill the shoes the next time in the shop.

Next I CNC milled a radius on the end of the coupler shank and drilled a hole for the pin:






Then a test fit to the frame:






I'm going to hold off on drilling mounting holes for the couple pocket until I verify the coupler height at the track. There's about 20 degrees of side-to-side swing as is, but I may need to narrow the coupler shank to get more angle.


----------



## steamer

Those brakes look pretty serious....no doubt they'll work well

Great Job Kvom! :bow:

Dave


----------



## kvom

I didn't feel like starting any complicated pieces today, so I decided to finish off the grate supports, one of the first parts I made in this project (back on December 8 ). I seem to have a habit of making "partial" parts leaving some details to be polished off later. This is probably a bad habit. In any case, I needed to machine pockets on the sides opposite the grate. Despite being simple in theory, I still spent all afternoon.

Here are the results:






The two pockets on the right side support are for the latch for the ash pan. Kozo suggests SS, but I just made them from CRS, and will paint.






Of course now I need the 5 pieces that go in those holes, so there's two more unfinished parts.

I won't get much shop time the rest of the week as the floors in the house are being refinished, and tracking in swarf is a big no-no.


----------



## metalmad

Hi Kavom
great build 
A steam engine is on the list 
I have the same problem with partial parts, which I really need to overcome as I often make it so much harder on myself then would have been the case if i'd finished the bit before taking it out of the lathe or mill.
Glad to see i'm not the only one :big:
Pete


----------



## kvom

Today was the first trial of the chassis on the tracks at my home club in Canton, GA. The assembly performed very well, with no problems on any of the curves or tight portions of the switches or frogs. With such a short wheelbase, the engine could probably handle a 20' radius curve according to one of the members present.

Here's a short video taken from the riding car.

[ame]http://www.youtube.com/watch?v=M0we2yqJo0M[/ame]

And sitting on the tracks afterwards.






The coupler height seems good, so I will drill and tap the buffer beam to mount the coupler pocket, plus shorten the coupler shank. For the next track run I want to have the side rods installed.


----------



## kvom

After yesterday's trial run, I proceeded to mount the coupler to the front bolster, cut down the coupler shank, and make a coupler pin to replace the screw I had been testing for fit.






Then, based on advice from an experienced builder in the club, I wanted to replace the retaining pin used to keep the side rods on the front crank pin. Kozo's design has a e-clip in a hollow at the back of the driver where it would be inaccessible after assembly. After trying a few things, I finished by using a brass washer held in place with a flat head screw; I countersunk both the crank pin and washer to get the screw head flat to the washer. A trial eyeball fit indicates that there won't be any interference with the conrod.






Despite appearances, the washer does not contact the side rod.


----------



## kvom

This was my last day in the shop for a while. I decided to finish the parts for the ash pan latch that I started earlier. Needed to make some smallish pieces but all was for the best. These are really finicky in 3/4 scale I imagine. Here's a trial fit photo:






I still need to silver solder all the bits together. The spring is the same as the return spring for the brakes, and is nice and firm. They came in a pack of 3, which was handy.


----------



## steamer

I like that KVOM...anthing that makes the engine more serviceable will be appreciated later!

Dave


----------



## kvom

It all has to be done eventually  But some parts are more "fun" to make than others.


----------



## steamer

Let me tell ya KVOM....once you start firing it...she won't be "pretty" anymore, and you will be working on her....trust me anything that makes that easier you will appreciate! 

Dave


----------



## Lakc

When its fully built up, will the chassis settle on the springs and make the coupler too low?


----------



## kvom

Right now the springs have no camber and the axle boxes sit midway in their range. If the weight of the boiler, etc. pushes the frame down too far, then I can add camber to the springs to raise it back.


----------



## Lesmo

That's a nice looking bit of kit you are making there, the progress of which I have been following with great interest. I like the video of your maiden run, which can be watched lying down. Very thoughtful of you.  

Cheers 

Les


----------



## kvom

Over the past two days I've been working on the tie plate, a part that mounts to the frames and provides support for the yokes that in turn support the valve gear. The initial machining was manual, with only the final radius cut (needed to clear the boiler) done on the CNC mill. For this operation, the aluminum fixture plate was drilled to match the mounting holes in the tie plate, plus two additional to retain the scrap part. Here's the assembly at the conclusion of the final op:







The two "feet" are screwed into the bottom notches to allow mounting to the frame, and then the two yokes can be trial fit.






There is a bit of interference between the bottom of the yoke and the driver flange needing to be relieved:






Kozo shows a small angled notch for this on the 3/4 scale, but I wasn't sure it would be needed at 1.5. 

I also went out to the RR this afternoon with the chassis to test it out with the side rods attached. Here's a couple of short videos:

[ame]http://www.youtube.com/watch?v=ym6Rl_eTRIQ[/ame]

[ame]http://www.youtube.com/watch?v=rkIadM9Ncu8[/ame]


----------



## Bernd

Love those video's Kvom. Thm:

Bernd


----------



## kvom

Today I took 5+ hours to get the first crosshead guide in place. As a novice builder, I struggle with knowing where fit and tolerances are important. But since I've had problems on stationary engines with crosshead guides, I decided to see how tight I could get.

Kozo shows soldering the yoke mounts and then machining to fit. I wasn't going to do it that way for several reasons, among which is the problem I had already soldering on the yokes where I couldn't get it hot enough. Also, the yoke was going to be modified from plan because of the width/gauge issues, so I prefer to do a fit "in place."

The yokes had 2 1/4" reamed holes for attaching the mounts, so my first task was to machine 4 of these from some 1" round brass stock. The mount body is .75" long, with a 1/4" diameter spigot for attaching to the yokes:






Lots of manual milling later, I have this:






The guides need to be parallel to the frame side as well as the frame bottom. I tried a number of ways to ensure the first parallel to the frame side, but eventually hit on this idea. I knew the distance of the bore centerline from the frame as well as the width of the guide, so I could compute the distance of the inner edge of guide from the frame. I then used gauge blocks to position the bar laterally.






the height gauge gave me the vertical distance at the cylinder end, and also the height of the mount top edge, so now I knew how deep a "notch" to mill in the mount. The final result with the first lower guide in place:






Measurement with a depth mic shows .004" vertical difference between the two ends; I'm satisfied with that result.

The upper bar will be a lot easier since I just need to make it parallel with the lower, via a parallel and some gauge blocks to get the needed measurement to make the upper mount. Even though the guides hold the mounts very tightly against the yokes, I'll loctite them in place.


----------



## steamer

Cool use of round stock. Did you index them about the pins while machining them?

Dave


----------



## kvom

I used a .25" 5C square collet block to hold them for the first light cuts on 4 sides. With the 4 flats centered on the pins, I could just hold them in the vise and take equal cuts on each side.


----------



## kvom

Since I lack material for the rest of the guides (and being burned out on them for the moment), I decided to make a start on the crossheads themselves. With the steel oblong I squared up a few weeks ago, I set up for the CNC mill. I had only .08" at the bottom for clamping with the vise, so was obliged to use soft jaws. Following Kozo's technique of initial machining of both crossheads from the same block, I first did roughing passes to get to here:






After the finishing passes, I had this:






The next step is to turn two round discs to fit into the heads forming a round-end pocket for the end of the conrods. These discs will be silver-soldered, after which the side of crosshead will be cleaned up with a facing pass. I'll have to see if my MAPP torch can heat the assembly enough for soldering.






Still lots to do on these afterwards.


----------



## kvom

This weekend I finished the other 3 crosshead guide bars and their mounts. For now they look pretty good, but we'll see if any adjustments are needed when the crossheads are finished.






I did the measurements with the frame on 123 blocks and surface table assuming that the cylinders are parallel to the bottom of the frame, which was the datum for the cylinder mounting holes. If that proves not to be exactly the case there is some play in the piston rod travel via the packing gland/bushing.


----------



## kvom

With only a few shop hours available today, I proceeded with the next step in the crossheads. I needed to silver solder the disks forming the pocket for the main rod end, but the MAPP gas torch couldn't produce enough heat. So I used my small Henrob oxy-acetylene torch for the first time. Then I cut the two pieces apart and face-milled both sides.






There are still quite a few operations to go on these parts.


----------



## Lesmo

Hi Kvom

those look very neat, a really nice job, but as I know nothing at all about these engines, I can't figure out where and how these parts fit. Maybe I should be patient and all will be revealed. ???
Keep up the good work 

Cheers Les


----------



## kvom

Third operation on the crossheads: use the CNC mill to profile the rear face.






Then I used the facemill on the Bridgeport to bring the thickness down to .75" with the pocket centered.

Les,

These parts link the piston rod to the main rod. The piston rod will screw into a threaded hole on the left, while the end of the main rod will slide into the pocket on the right and be fastened by a pin that will drilled through the center of the crosshead. The flat top and bottom will slide between the guide bars that I installed a couple of posts earlier.


----------



## kvom

More work on the crossheads including an "O $hit". First task was drilling three lateral holes: 3/16 reamed for the retaining pin, and two 5-40 tapped holes to mount the link bracket.






Then I drilled and tapped the front side 5/16-24 for connecting the piston rod, but then discovered that the threads weren't straight. I had started the tap with the mill spindle, but apparently didn't get enough turns to ensure straightness. Plus it was a crappy carbon steel tap (I should know better by now). So I'll order a HSS tap before doing the other. For this one my plan is to bore out the hole to 3/8", then drill and tap some 3/8 rod on the lathe and press it into the crosshead.






I spent the rest of the afternoon making the cross pin that connects the crosshead to the main rod. This simple-looking part took a lot longer than it might appear. The center is drilled 3/16 to accept a Gits ball oiler, tahen 3/32 to 4 cross holes that will allow oil to reach the bronze bushing in the rod end. The threads are 5/16-24, and the inner side of the crosshead will be countersunk to avoid any protrusions that could interfere with the side rod.
















Next shop session I'll try to make the second one come out as good.


----------



## kvom

Today's plan was to make the link brackets and union links shown on page 104. These are simple CNC profiles, with the holes drilled on the Bridgeport to serve to attach to a aluminum fixture plate. Here's the setup for the link brackets; all holes and screws are 5-40.






A few minutes later:






Then it was back to the Bridgeport to enlarge the single hole on each to 5/32.

Test fit for to the crossheads, where I discover that the crossheads should be mirrored wrt the brackets, and one set is on the top of the crosshead. grrrr. The union links are shown as well, along with the second crosshead pin that I made yesterday.






I think the simple fix for the bad holes is to loctite a SS screw in each and mill them flat, then drill and tap new holes in the correct position.

My order from McMaster came in just now, so I should have a good 5/16-24 tap to try threading the piston rod attachment properly.


----------



## kvom

Today's project was to finish the combination levers (p. 103, fig 17-9). These had 4 main machining setups. First was to mill lengths of 1/2" square bar CRS down to ~.410" square, drill the 3 holes 5/32", and mill the recess flat where the union link connects. A small aluminum fixture plate is then drilled with matching through holes so that the prepared stock can be attached with 6-32 screws and nuts. The left hole is indexed from the plate's edges so that the machining zero point can be located for the CNC mill.






The second op is then to mill the profile. Here I used a .25" carbide endmill, .125" DOC at 7IPM and 4000 RPM: conservative F&S.






Now the fixture is mounted vertically in the vise, and the "cutout" is machined, again with the .25" carbide endmill. This cutout is needed to clear the main rod.






The final op is to cut the slot where the end of the radius rod lives. Here I used a .125" carbide endmill, .05" DOC, 3IPM, 4000 RPM.






And the final parts:






The radius rods will be done in much the same way, although needing a longer fixture.


----------



## stevehuckss396

Nice looking parts!! You are really knocking this thing out of the park. Looking forward to the next set of pix!


----------



## Lesmo

I was pleased to see that the crosshead (Oh $hit) was easy to overcome and did not require a remake. Thats the sort of setback nobody wants.  The build is all looking very good so far, and I cant wait to see it running under its own power.

Cheers Les  :bow:


----------



## kvom

Yesterday I machined some raw stock to size for the radius rods, and today I started to machine them. The first went in the scrap bin, but lesson learned for the second. Following the same process as for the combination rods, I first did the "top" profile:






Then the "side" profile:






Finally the slot:






And a bit of fit up to show how the valve parts done thus far fit together:


----------



## Lakc

That looks like a heck of a lot of fun. Your doing a lot to combat my near total ignorance of steam locomotives. Thank you! :bow:


----------



## kvom

After making the second radius rod yesterday, I decided to tackle the expansion links (p.106). These are each comprised of three pieces screwed together with 8-32 screws. I did each of the three pieces in pairs from one pieces of steel for each pair, using the same fixture plate for each. The holes for mounting to the fixture were drilled on the Bridgeport prior to moving to the CNC mill.






The radius rod does fit but is a bit tight at the ends, so some sanding/filing will be needed eventually.

The next step will be to make the 1/4" round for the center holes in the outer plates' these pins will fit the brackets that attach them to the yoke and allow them to pivot.


----------



## kvom

I made the doodads for attaching the expansion links to the yoke brackets, and then decided to attack the "bad" crosshead in an attempt to save it. I drilled out the crooked threads, tapped the new hole 7/16-14, and secured a 7/16-14 bolt in the new hole with red loctite. Also used red loctite to secure screws in the bad 5-40 holes. After a couple of hours cure, I used a hacksaw to cut off the three screws and milled the stubs flat.

Next I re-drilled and tapped the 5/16-24 hole for the piston rod connection, this time using my nice new HSS tap. All looks OK.

Then I cut some 1/8" brass to use for the crosshead slippers.

Finally started to try to fit the left crosshead to the guide bars. I used Kozo's method to mill the channels for the guide bars, using the piston rod on parallels to ensure that both channels are parallel to the rod. For this I had to take the piston off the rod. I milled the slots to match the bars without slippers; Once I get a decent fit this way I can deepen the channels by the slipper thickness. The first try afterwards fitting the cylinder, head, guides, and crosshead to the yoke ended up being too tight for the crosshead to move. Measurement showed that the yoke side bars were over .015 closer than the cylinder side, so it appears my mounts weren't measured as good as I thought last week.

My immediate goal is to get the first crosshead adjusted properly fore and aft, and then I can see how much I need to narrow it or elsewhere to avoid hitting the front crankpin.


----------



## kvom

Spent a good amount of time milling the first crosshead and guide bars to allow the head to slide on the guides freely. They're still a bit tight at the rear so a few more thou clearance seems to be needed. The crosshead doesn't have slippers yet, but once it move freely on the guides then milling the slots to adjust for them should be straightforward.







With the guides and crosshead pretty close to good, I was able to investigate how much the front crankpin interferes with the crosshead. With the wheel tight against the axle box the pin just clears, but at maximum side play I get this:






I measured the side play as .071", so I plan to shave .080 off the pin and crosshead between them, and the same amount from the front end of the side rod bushing as off the pin.

I also did a quickie lathe job to make the bronze bushings for the main rod's small end, now that I have made the pin's diameter at 5/16". The next re-assembly I'll try to get the side and main rods attached and check the full range of motion.


----------



## ozzie46

Looks good Kirk. I'm glad you were able to save the cross head.

 Looking more like loco each update.

 I silver soldered bronze slippers on my Simplex cross heads too. The plans called for case hardening the cross heads but I don't have the equipment for that right now.

 Ron


----------



## kvom

Rather than disassemble and mod the crossheads/crank pin, I decided to go ahead and make the link brackets and link blocks, so that I could test the fits there. For the link brackets, they are CNC'ed two to a fixture so that the two holes are present to secure the stock to the fixture.






Then I machined this pocket into a soft jaw:






The pieces are separated and held in the pockets to remove the excess from the bottom, and then to mill the relief cuts.






I ended up with 3 after screwing up one via a brain fart.






So I need to remake the others and then drill tab the mounting holes, but that's for another day.

While the above process is straightforward, I spent the entire afternoon on these as I needed to revise my programs a good number of times. The remake should go quicker.


----------



## doubletop

Kirk

We are probably guilty of not giving you enough credit with your work here. Its some amazing stuff, and you keep churning it out.

Fantastic

Pete


----------



## kvom

Thanks to all who look in. I'm enjoying the build, trying not to do too much at a go so as to get burned out.


----------



## kvom

I finished up the expansion link brackets by drilling and tapping the mounting holes. Here's a technique for making sure they're vertical in the vise:






Trial mount on the yoke with the expansion link assembly. It rocks very smoothly.






So I decided to do a trial fit of a lot of the made parts, holding them together with some screws:






Nothing looks too out of place, although I need to have a few more parts made before I can check the full range of motion with everything connected. Assembling everything is quite a puzzle as to the order needed. For example, with the wheels installed the bottom mounting screw for the yokes are inaccessible:






And as well the crosshead pin that holds the main rod can't be inserted.. On the other hand, the side and main rods can't be installed with the yoke mounted. So it seems that the tie plate needs to be removed, install the rods, then bolt the yoke to the tie place and install the pair as a unit. Still some experimenting to do.

In any case, I took it all apart, took .030" off each side of the crosshead and .020 off the side rod bearings and reinstalled as a check. Still some interference between the front crankpin and the crosshead, so the next task will be to shorten the crankpin.


----------



## steamer

Looking Great Kvom!

Nice trick with the parts in the vice!

Dave


----------



## stevehuckss396

That looks great!


----------



## Lesmo

Pete is absolutely right Kirk. This is quite a complex bit of kit, as your temporary build illustrates, making your progress so far even more deserving of our applause. Keep up the good work. Oh, and thanks for the tip.
Cheers Les.


----------



## ozzie46

Keep up the good work Kirk.

 Ron


----------



## kvom

With other commitments this week, I got only a few hours in the shop the past few days. The first order of business was to get the right side crosshead and guides lined up properly with clearance for the crankpin. This went a lot smoother than the left side.






I also wanted to provide an oil supply for the front axle bearings. This would have been done much, much easier had I considered it before mounting the drivers to the axle. Holding the axle and drivers on the mill was a problem, but I finally came up with this setup for the 3/32" radial hole:






Then drilled a hole down the axis to meet as well as a 1/4" hole for the ball oiler:






Unfortunately when doing the other side the drill broke off in the axial hole, so I'm not sure what I can do about getting it out.

I then installed one of these oilers onto one of the main rods:






These are threaded 1/4-32, so I had to order the tap along with the oilers from McMaster. I plan to use these on the side rod ends as well as the top guide bars once I tear everything apart the next time.

The next tasks in view will be to fit the slippers to the crossheads and make the link blocks. With those done I can contemplate mounting the full valve assemblies on both sides and possibly towing the chassis around the club track once again.


----------



## stevehuckss396

Looking great so far! Sorry about the drill breakage. Is there someone in your area with an EDM machine?


----------



## kvom

The "easy" solution will be to remake the axle, as it and the crank pins are just fixed with green loctite. However, I don't currently have the necessary big v-block with a clamp to redo the quartering.


----------



## Lakc

Drilling intersecting holes always seems to be the culprit. I have yet to see any surefire tips on how to accomplish it without drill breakage. If you cant stuff something removable in the first hole I tend to just pray and go very slowly when the drill is about to break through.


----------



## kvom

A short session in the shop this afternoon resulted in this






I mounted the screw in ball oilers on both side rods, the top guide bars, and the other main, plus drilled and countersunk the brass slippers. Then drilled and tapped the slipper mounting holes on one crosshead. Although the 5-40 screw heads are countersunk, I think brass screws, if I can fine them, would be superior.

Hopefully I can finish fitting the slipper to both crossheads next time out.


----------



## dalem9

Hi I beleive that your brass slipper are to be set dipper so that it will stay on your guide bars .Please let me know . I am also building this engine . Dale


----------



## kvom

dalem9  said:
			
		

> Hi I beleive that your brass slipper are to be set dipper so that it will stay on your guide bars .Please let me know . I am also building this engine . Dale



That's correct. The crossheads currently have the slipper channels at the correct depth to match the guide bars. So for each I can measure the distance between the bottoms of the slots, and shoot for the top of the slippers being the same distance. Since I made the slippers from .125" brass sheet, my original intent was just to machine each channel .125" deeper. However, checking the drawing dimensions makes the clearance with the inner cavity a bit thinner than I like. So I plan to reduce the thickness of the slippers to .08" in line with Kozo's dimensions.


----------



## dalem9

Sounds great just through I would mention it nice work ,I am building mine in 1/32 scale.Thanks Dale


----------



## ozzie46

Looking good Kirk. I agree that brass screws would probably be better. 

 I was going to use screws like you did but I don't have anything smaller than 2-56 taps so I silver soldered them on. I hope I don't regret that choice later.

 Ron


----------



## kvom

Got the crossheads machined, slippers installed, and fitted to the guide bars. These took more time and trial and error than I had anticipated. One issue that cropped up was my 5-40 flat head allen screws. With the slippers only .086" thick, the heads were still proud of the slipper surface even with countersinking. My solution is shown here:







I drilled and tapped a short piece of 1/2" aluminum rod and used it as a "fixture" to hold a screw and lock nut. Then I used a grooving tool to take down the lower part of the head taper. Hopefully this is a temporary necessity until I can get some brass screws, but I am thinking that using loctite as well as the screws may be a good plan.


----------



## kvom

Thanks to John (FLSTEAM) for the idea, I now have slippers that don't need screws. Thanks John.











The crosshead slide pretty smoothly when I turn the rear wheels to drive the rods.

Now I can get on with the die blocks (link blocks per Kozo). I got the material and a fixture ready today, so CNC tomorrow.


----------



## ozzie46

Now that is one neat idea!! 

To bad mine are already silver soldered.  :-[ :-[ :-[ :-[

 Ron


----------



## kvom

SS slippers are not a terrible idea. You can solder them in and then machine to fit.

Today I took a shot at making the link (or die) blocks, which are a vital part of the valve system. They need to be a good sliding fit to the curved expansion link grooves. Since the radius of the larger curve is over 7", it's pretty hard to even see the curvature once the block is made (it's ~ 1/3" wide). I went through two pieces of material before I got one good part, and that's with about 5 hours of shop time.

I start with a 2.5x.75" piece of 1/4" steel and mill the faces to .130" thick, then drill three holes.  Two ar for mounting the blank to an aluminum fixture plate with 5-40 screws, and the other is a 5/32 hole that will attach the link block to the radius rod via a pin. The blank is then machined down to this on the CNC mill:






I then used the expansion link to check for fit. I needed to modify the program a couple of times to get the fit I wanted. The last pass took .001" off the radii.






Then the CNC program cuts the sides, leaving .010" at the bottom. The block gets detached and has the sides filed.






Finally:






I still need to file the ends of the expansion link flat, as well as making the other block and the pins, before assembling everything again.


----------



## Lakc

Congrats, thats a lot of work to do it right. I think I may have been tempted to just take a file to that curve in the first place.


----------



## kvom

Not a lot to show since the last post (too much tennis and football to watch). Parts I did complete are:

1) The reverse shaft bearings (pg. 114, fig. 18-16). I made the shape a bit different from Kozo's to make them easier to machine. I also drilled/reamed the holes 1/4" rather than Kozo's 5/32" as I have a good quantity of that size drill rod. I am now thinking that a bronze bushing here might be a good idea to avoid steel on steel movements.






I also made the radius rod hangers (fig. 18-17); these are called lifting links in another model I've attempted. In any case, they are pinned to the end of the radius rod and are part of the reversing linkage.


----------



## Brian Rupnow

Kvom---You are a very dedicated modeller, and you do beautifull work. I admire the things that you build and post here.----Brian


----------



## kvom

Thanks for looking in, Brian.

With not a lot of shop time available this afternoon I decided to do a simple part. However, it seems that the stock prep, fixturing, and setup take just as long for the simple parts as the more complex ones. In any case, here's the quadrant (p. 112, fig 18-5). It would been just as efficient to machine the stand and quadrant from a single piece of stock it seems. Anyway, that's for another time.


----------



## Lakc

Your rapidly expanding a collection of machined steel there. Are you going to paint it all or give it some chemical blackening treatment?


----------



## kvom

I'm not sure what parts to paint or otherwise coat, or else leave bare. Some parts might get nickle-plated.

Today I worked on the quadrant stand, which has two pieces soldered together. Here's the main vertical part along with the previously completed quadrant:






The three pieces screwed together as a test fit; the stand is a bit over 3" tall:






With the stand and its base silver soldered together. I used a bit too much solder wire, so will have to file off the excess:


----------



## kvom

This afternoon I machined the base form of the reverse lever, and then make the 2-piece reach rod that will connect the lever to the reversing arms. Since I had no 5/16 drill rod as per plan, I made the rod from 1/4 drill rod. The adjustment end is threaded 6-32.


----------



## kvom

A short Sunday shop session today was devoted to making the "latch lever", which attaches to the reverse lever and allows for latching the reverse lever to the quadrant. I had a piece of 7/8 square 12L14 bar rescued some time ago from the school scrap bin. The first operations were to CNC mill the side profile and drill the mounting hole for a 6-32 screw:






Then the bottom profile, also via CNC:






Finally manual milling operations to whittle the lever away from the attached stock:






The part is a bit more than 1.5" long. It still needs a bit of polishing.


----------



## kvom

I made a bit of progress on the reverse lever and running board, but first had to remake the support plate and get it square, which took a bit of time.






I'm going to have to remake the running board as I discovered that I had drilled the mounting holes on the yoke 1/16" too close together. While I could likely fudge a fix to that, I don't like the material I used. I started with some nominal 1/4" CRS, but by the time I had milled off the slag on both sides the thickness was down to .200". I had to clamp it on the mill table and use a 1.25 facemill, but the need to move it couple of times because of clamps and its length (27") made the machined finish less than ideal. Maybe a thick coat of paint will cover the tool marks. In addition, there's a perceptible arc, which I might be able to straighten with a press.

Is there some standard stock that I can order (width is 2.5") that has a good enough surface to paint directly without milling?


----------



## Lakc

Most anything cold rolled will, but if your machining one face of it the stresses will warp it.


----------



## steamin

If you were machining "slag" off the surface, you more than likely was using "hot rolled" steel. True cold roll or 1018 steel is clean except for the grease and oil they put on it to keep it from rusting. It comes in many forms and shapes. Check with Speedy Metals. He's their link: http://www.speedymetals.com/
Larry


----------



## kvom

Not a lot of visible progress as we had a 3-day meet at the club, plus I've been doing a few small parts not photo-worthy. The past couple of days have been for painting some parts (low gloss machinery enamel). I did make the reverse shaft (pg. 114, fig. 18-14). In the 3/4 scale version it's made with 5/32" round rod bent manually, but using 5/16 didn't look possible, and even with torch heating getting the ends to stay straight and aligned looked very iffy. My solution was to mill the curved section from some steel plate, and then press 1/4" drill rod into each end. Not that pretty but it appears to work:






As the assembled parts are now reaching a weight that I don't want to be lifting by myself, I've wanted to get some sort of rolling cart with rails to hold the loco in the shop, along with a railed sheet for transport in my truck bed. I found this computer desk at a local thrift shop (for all of $5). It's made of pressboard of some type, but the boards are thick and the desk and wheels seems sturdy enough. I also found some leftover T-beam steel in the garage which will serve for rails, and I bought a piece of 1x10" pine 4' long for the truck bed. So for a total of $12 in material cost I don't think I can go far wrong.






My plan is to make the truck bed carrier first in order to determine height of the rails off the ground, and then adjust the rails on the cart to match.


----------



## kvom

The first job today was to afix "rails" to my transport plank. The rails are 1/4" square steel bars fastened with wood screws (holes were countersunk). After moving the chassis to the board, I discovered that the drivers and side rods still rub on the yokes as the spring rigging is not installed. Seems to me that they shouldn't rub anyway, so I'll plan on milling some additional relief on the yokes.






I'll add some eye bolts for hold-downs.

Then I spent some time cogitating on the cart, how to load from the cart to the truck bed, etc. etc. The first problem was that measurement showed that the top of the cart is 6.75" lower than the truck tailgate. Rather than try to shim a railbed that high, I figured that using the auto lift to raise the engine to the truck bed would be the most sensible idea. Some experimenting with pieces of lumber left over from the shop build finally yielded a workable idea as shown below. Please remember that my engineering degree was from 1971 and is a bit rusty.






So 4 pieces of lumber. The bottom gives a base, and attaching it to the two "ties" prevents them from racking. The ties give clearance for the arms of the lift to go under the rails, which are supported by 2 2x4s. The rails themselves are just lengths of steel with a T cross-section. Everything will be connected with screws.

After some more thought, it occured to me that I don't need the roll cart. I can leave the loco and support mounted on the lift to work on it, and then when I need to use the lift or the parking area I can lower it onto two wheel dollies like the one shown in the photo on the right. I can then wheel the loco around with the dollies.


----------



## kvom

I got the support "cart" screwed together this afternoon and mounted the chassis on the "rails". With the base plank on the wheel dollies it's easy to move about the shop floor:






I can wheel the assembly under the lift arms and then raise it to a nice working height.






Now back to working on the parts.


----------



## ShedBoy

Great lift. I hope there is something stopping it from rolling off the end it would be a shame, no disaster if it fell off. Just wondering what it will weigh when done?
Brock


----------



## kvom

Because the wheels rub without the springs rigged, the loco as shown won't roll by itself. I did put some clamps on the rail ends after the photo. Loco with boiler should end up at about 150 lbs.


----------



## dalem9

I had a desk like the one you got ,be careful that the wheels don't split out the side of the press board. I would hate to see it tip over and smash all your hard work. Dale


----------



## kvom

Very long afternoon in the shop to get ready for pulling the chassis around the track tomorrow.

I milled a bit off the yokes to eliminate the main rod rubbing, reassembled the pistons to their rods, then got the rods, crossheads, etc. all assembled. The chassis rolls quite well on the stand; this was the first time the piston were driven inside the cylinders since all the fitting was done with just the piston rods. Then I reattached the spring rigging. At that point the chassis was quite nose heavy, so I added the temporary running boards and a chunk of steel across the frame at the rear, plus screwed in the grate holders. With extra steel rearward, the chassis seems pretty well balanced.

I also decided that with the "stand" mounted on the lift arms, I might just as well use it as the transport too, since I can lower the stand and loco into the bed of the truck using the lift. So I added some eye bolts on each end to allow a ratchet strap to secure the loco to the stand during transport. Here's the result at end of day:







While not needed for testing the chassis motion tomorrow, I screwed on the steam chests and tops, plus the front cylinder heads to keep any dirt or dust out of the cylinders.

Yesterday I located a reducing bushing to adapt a 3/8-18 NPT male hole to a 1/4-18 female NPT fitting; a friend has a 3/8 tap that I'll use tomorrow to tap the supply hole in the tee, which I drilled out to 9/16 today. I'll need to do a pretty complete disassembly to install the tee as the frames must be separated. So the next assembly will have as its target to run on air. I need machine only 4 more significant parts, and the rest are pins and other fasteners.


----------



## Maryak

Kvom,

That's just the "Ants Pants" :

I have never built a model loco but at 12" : 1ftwhen moving a loco from a.....b by towing it's always done with the cylinder drains open. I don't know what is fitted and what is not fitted inside your cylinders/steam chests but you don't want to over pressure them or lock up your wheels on the track.

Hope I'm not being a smart ass and that it helps.

Best Regards
Bob


----------



## kvom

Thanks for looking in, Bob. I have not as yet drilled or installed any cylinder cocks pending a decision on buy vs. build and type. I am leaning towards steam-operated cocks. The cylinder heads are on loosely, the o-rings in the packing glands are not there, and the rest of the openings are just covered with tape, so pressurizing is not an issue.


----------



## kvom

The on-track test run yesterday went pretty well. I pushed the chassis around the main loop (2 miles) without incident, so when I disassemble it I'll see if anything looks amiss. I did lose one of the spring gibs which popped off somewhere. These are simple and easy to remake. I was warned by another builder that this particular system wasn't ideal, but if/when I camber the spring packs the gibs should be more secure. Didn't get any pics as I was doing the run solo.

I also found that the "rails" on my stand are a bit too close together. The loco rolls on them fine, and unloading onto the lift was smooth, but reloading didn't work too well as the lift's track didn't line up well enough. I plan to move one rail out about 1/8".

I talked to another builder about fixing the oversize hole in the tee. I'm going to machine a round plug and press it in, then weld the seam, and finally drill/tap for a 1/4 NPT connector.


----------



## kvom

Started on doing a few simple things that always seem to take as much time as the big parts. First up was starting to fix the oversize steam supply hole in the tee following a club member's recommendations. I used an endmill to enlarge it and remove the cocked threads, then measured the hole with a bore gauge I bought a few months back and hadn't used until now. Then turned a steel plug .001" undersize and pressed it in using the 3-ton arbor press. After milling the top of the tee flat the joint for the plug is almost invisible, but my friend might want to tig-weld the edges anyway. After I'll drill and tap 1/4-NPT for an air fitting, and later a compression fitting for steam. That was the first time I'd machined a press fit steel on steel, so I was pretty happy with the result.

Then the simple spacers for the quadrant (need paint) plus the pin for attaching the reversing lever to the quadrant. I made this from brass rather than steel hopefully avoiding rust later on. The pin is retained with an e-clip on the other side.






\

Next I made the two square valve nuts; these are ~.5" on a side and drilled/tapped 10-32 to match the valve spindle. When I went to try a fit on the cylinder I discovered that the groove in the valve where the nut lodges wasn't deep enough by 1/8" *(I had misread the plans). So back to the mill to *(carefully) deepen the groove on both valves. Seems to fit well now.


----------



## Fuelrush

Awesome! Looking good! I'm still working on my 3/4" A3 but I'm way behind you. I hope you get lots of video of your loco because there is a serious shortage for how popular the Kozo A3 is. Youtube has maybe 3 videos that I know of where you can see it running. 2 on test stands and 1 on track. Again awesome work!


----------



## agmachado

Hi,

Very cool results... Lots of patience!

Cheers,

Alexandre


----------



## kvom

The work for the past couple of days was finishing some pieces to do a trial fit of the valve parts. First up was filing the ends of the slots in the expansion links square to the die block, to allow full-travel. I did the first one by hand, but then said to myself, "why am I doing this when I have that little antique die filer I bought a while back and have never used?" The second one went a lot quicker.






After quickly making a couple of pins, the expansion links and radius rods were attached.






Then the trunions were screwed together, but the resulting assembly clamped the radius rod too tightly to move. Some experiments showed that it's the outer "arm" of the rod that's too thick, or the trunion is too thin. For the time being I inserted some thin washers as shims.






Now I tried to put it all together on one side, using some screws as the needed pins/e-clips aren't made yet. Most everything went together pretty well.






I found a few places that rub. The top of the inner expansion trunion just touched the bottom of the reverse lever bracket.






And the bottom of the combination lever rubs the lower crosshead guide (apparently a known issue with the plans).






I also found that the main rod was interfering with the inside trunion, and some examination shows that the spacer bushing on the rear crankpin is too wide, pushing the end of the rod out. I'll need to take about .050" off to correct the problem and get the main rods parallel with the side rods.

I took it all apart again. In addition to the above fixes I need to machine and attach the 3 reversing arms to the reverse shaft, plus make the temporary eccentric rod. The chassis-on-air goal is in view, but still lots to do.

I had been wondering how hard it would be to adjust the valve nut in order to set the valve travel properly. It turns out that by unscrewing the steam chest from the cylinder the chest and valve rod can pivot up on the combination rod pin making the nut easy to access. Given 32 thread/inch and a square nut, a quarter turn of the nut gives an adjustment of 1/128" (.008), which ought to more than enough precision.


----------



## kvom

My order from McMaster arrived at noon: o-rings for the engine and a 1/4-18 HSS pipe tap. The rings serve as the packing glands for the piston and valve rods, and are made of Viton rubber. They come in packs of 100, and since I needed only 2 of each size I have a lifetime supply. Sizes needed are 010 for the 1/4" valve rod and 012 for the 3/8' piston rods. After installing the rods seem to slide as well as they did without, so we'll see if the rings seal as expected.

I decided to finish drilling and tapping the steam supply port in the tee now that I had the correct tap, so after drilling the hole in the plug (7/16" diameter), I found that the square end of the tap was too large for my small tap wrench. I jury-rigged a substitute by combining two wrenches, a 12-point box end and a standard. that could both fit onto the end of the tap. I used a dead center mounted in the mill to ensure the tap started straight, and with the wrenches pointing in opposite directions I could keep even pressure. With lots of tapping fluid and removing the tap a couple of times to clear chips, I got the tap to the needed depth fairly quickly.






I also got the eccentric trunions and combination lever issues fixed, but ruined one of the reverse lever brackets when the part slipped in the vise. So I plan to remake both with a bit of extra clearance for the eccentrics.


----------



## Lakc

Your coming a long way in an awful dang hurry, excellant work!


----------



## kvom

Over the past few days, I have been working on the reversing gear. The first task was to machine the two arms I hadn't already done. The smaller one attaches to the reach rod and thus to the quadrant lever. The longer two are connected to the radius rod by the hangers.






I had disassembled most of the drive gear from the chassis, so I replaced the yokes on the tie plate and mounted the eccentrics. Then mounted the reverse arms on the reverse shaft at the distance from the shaft's center indicated by the drawing:






I attached the assembly to the yokes and was happy to see that the reverse arms, hangers, and radius rods all lined up.






Now it was time to drill the mounting holes for the three arms into the ends of the shaft using the angular positions show on pg. 114, fig 18-20 of Kozo's book. I needed a way to hold the shaft at specific angles, so I decided to make a little collet clamp from a piece of aluminum.






I drilled the hole .01" from the edge and cut the slit with a coping saw.

I could set the necessary angles using angle bars against the sides of the shaft, and then clamp the rod tight in the vise. Then it was just a matter of setting the position with the DRO and edge finder and drilling the holes.






Remounted on the yokes, it was time to set the reach rod. I had to cut off a few threads on the far end to get close.






With the reversing lever all the way forward, the reverse arms are supposed to be horizontal. I had to remove the spacers on the quadrant to get the necessary full range shown on Kozo's drawings. If I lengthen the reach rod to avoid this, then the neutral position is away from vertical. I'll wait until it's time to set the valve timing before seeing what's needed for full forward and reverse. For now it's pretty close.


----------



## metalmad

Hi Kvom
Its looking great !
 :bow: :bow:
Pete


----------



## kvom

Now I need to continue finishing up lots of little stuff before it can run on air. The only large parts to do are the eccentric rods, but these can't be completed until I know the exact distance between the rod ends, and this distance must be measured precisely once all the rest of the valve mechanisms are adjusted. The measurement also needs to be done separately for each side. To do the measurement, a temporary adjustable eccentric rod is needed, so that's one of today's projects. I made it from two 4.5" pieces of .75x.125" steel bar.






The screws are .25", and in one of the bars there are slots allowing the total length to be adjusted +/- .10". The holes on the ends fit into the pins on the return crank and the the eccentric. When these two pieces are positioned correctly, I put on this bar to fit and tighten the nuts to lock in the length. The bar then serves to measure the distance between holes drilled in the real eccentric rod.

I also made a brass plate to seal off the bottom of the steam supply hole in the tee. Under steam, this plate will be modified to connect to the lubricator and admit steam oil, but I'm not ready to make that yet. I chose brass so that the steam oil conduit can be more easily silver soldered.

Finally, I wanted to start to smooth the top of the cylinders where the valve slides. Kozo recommends wet sanding with 400 grit wet/dry paper, which I lack. So instead I sanded the valves using different grades of paper through 320, and then a final pass with 600. Tomorrow I'll try to get some large sheets of 400, plus some coarser grades to start. It would be nice to surface grind these, but paper will have to do. Rather than try to do a lot of sanding on the fit between the ends of the tee and the cylinders, I plan to install gaskets here even for air.

My 5/32 drill rod also arrived from Enco today, so I can also start making the pins for joining the valve gear components.

As Jack Bodenmann says, no lack of things to do.


----------



## kvom

The past couple of shop sessions were devoted to tearing the entire chassis down to individual pieces so that I could get the tee between the side rails. Then I could attach the cylinders to both the tee and frame rails. I made some gaskets from a fiber sheet I purchased at Ace Hardware, and coated both sides of the gaskets with anti-seize, this being on the advice of a fellow builder.

With that done I could start to put things back together, this time sitting on my surface plate that would be needed subsequently.






With the valve gear and rods installed, the first part of valve tuning is setting the return crank. To do this, the crank pin needs to be at dead back center. I measured the wheel diameter with the height gauge as well as the diameter of the crank pin, and was thus able to calculate the necessary height of the bottom of the pin above the plate. Using gauge blocks to make up this height, I moved the chassis until the crank pin was pressed against the blocks.






I locked the chassis in this position by clamping the front driver, placed the return crank on the crank pin, and rotated it until the 1/4" pin was pressed against a second stack of gauge blocks. The center of the link pin is supposed to be directly above the center of the axle. Since I knew the distance between the holes in the crank and the distance of the crank pin center and the axle center, a bit of trigonometry yielded the height of the gauge block stack.






After tightening the clamp screw on the return crank to lock it in place, I now used the temporary eccentric rod to attach the crank to the eccentric. 






Now I followed Kozo's instructions to position the eccentric such that moving the radius rod up and down fully causes no movement in the valve. Once I had a good position I could tighten the lock screws on the temporary rod. I then measured the distance between the rod's holes by clamping the rod in the mill vise and using the DRO. Doubling Kozo's estimated length gives 6.054", while mine measures to 6.148". Given that my wheels are slightly larger than Kozo's scaled plus all other machining variances possible, I'm pretty happy with the result. The same measurements need to be done on the other side next time out as the length is likely to be slightly different.


----------



## ShedBoy

That is real pretty Kvom, gerat work as usual.
Brock


----------



## Maryak

Kvom,

Wow :bow: this is coming along great guns and pretty fast as well :bow:

Best Regards
Bob


----------



## kvom

I declared victory on the eccentric rod too soon. In addition to the radius rod not moving the valve, the pin attaching the eccentric to the rod needs to be close to level with the axle center. Since the 3/4" scale model has no springs, the axle can't move relative to the frame and eccentric, so there's no problem. However, the 1.5" scale has springs and sliding axle boxes. My setup was without springs, so the frame slides to the top of the axle boxes leaving the eccentric pin lower than the axle center.

I measured the height of the eccentric pin center with the temporary eccentric rod installed, and it is .182" lower than the axle. The obvious solution would be to try to raise the frame .182" and remeasure with the temporary rod. However, since the eccentric itself would be in the same position relative to the valve, I realized I could use trigonometry to solve for the new value, which turns out to be 6.124".


----------



## don-tucker

Excellent Kirk,A really nice job
Don


----------



## kvom

I got some shop time this afternoon, so it was finally time to work on the pins for the valve gear (p. 108 in the book). These seem to be more finicky for me than they should be, but I did manage to make four for the one side I have assembled plus one for the other side. I really should have soldiered on, but my feet were telling me I'd been standing too long. The e-clips for the union link were a PITA to attach on the inside where they belong, so I reversed them for the time being. Better to pre-assemble these, which I'll do on the left side build-up.

I discovered that "somehow" the pin for the left side valve spindle had been drilled 3/16 rather than 5/32 like the right. These are the parts my daughter helped make a while back. So I just enlarged the matching holes in the combination rod to match and remake the pin with 3/16 drill rod.

7 pins to go, so hopefully I can speed up and get them all done the next time in the shop.


----------



## dalem9

Yea the pins are a pitb mine are 1/16 ,and the clips keep coming off.So I am going to try to figure something else out.Dale


----------



## kvom

Even the 1/16 shouldn't pop off. Are you milling the slots too deep?


----------



## dalem9

I am not sure just what the problem is .Withthe pin being just 1/16 there is not much left after making the groove .I am thinging of making shoulder bolts for some of them . This is my frist model so I have a lot to learn.Thanks Dale


----------



## ref1ection

Waiting patiently for the next update. I bought the book just to follow along. :big:


----------



## dalem9

http://thehobbyistmachineshop.com/PenA3/HTML/PA3_Springs.html  Kvoncheck this out ,you my like this. Dale


----------



## kvom

dalem9  said:
			
		

> I am not sure just what the problem is .Withthe pin being just 1/16 there is not much left after making the groove .I am thinging of making shoulder bolts for some of them . This is my frist model so I have a lot to learn.Thanks Dale



I just realized you are building half the Kozo scale, so perhaps the e-clips don't work well that small. Given that the groove diameter on all the clips I use is .025 less than the pin diameter, that would mean only .038" of material left.

I have been sick with a cold/cough for the past few days, so not in the shop. Saturday I'm driving to KY to pick up a tender tank, to which I will be adding Tom Bee trucks. So no tender fab for me.


----------



## xo18thfa

Gorgeous work. Thanks for the extra effort to post all this.


----------



## kvom

Saturday I was well enough to make an 800 mile round trip to pick up this tender, which was advertised on DLS. I didn't like the slant back tender that was normal with the A3, and this looked to be well made. With some Tom Bee trucks and a seat made to fit, it should work well with a small locomotive. It has a single water valve on the left side, so if I go with two injectors I'll need to add another on the right.







Today I decided I really, really needed to do something to make some progress on the build. So I repeated the Kozo valve timing process on the right side using the temporary expandable eccentric rod, then calculated the revised length assuming that the axles and piston rod would be on the same level. This side turned out .003 longer than the left. Then I made some temporary eccentric rods from some 1/8" steel stock using the calculated spacing for the holes. I don't want to do the real rods until I'm sure the lengths are correct. I'll need to finish making the last 4 pins for these rods, and install them with spacers of some sort, since the real rods will be .25" thick.






With the rods installed, I just need to adjust the pistons to be centered in the cylinders over their range, and then close up the cylinder heads and steam chest covers to give air a try. This stage always makes me "nervous", since every model I've made in the past has taken lots of fiddling to get to run.


----------



## Maryak

Nice find kvom. :bow:

If you don't want to make another outlet in the tender you may like to think about running the injectors off a "T" piece.

Best Regards
Bob


----------



## kvom

My understanding of injector operation is:

1) turn on the water
2) turn on the steam
3) reduce water flow until injector overflow stops losing water

If the two injectors have different water needs or I just need to use one of them, I'd still need separate valves for each injector's supply. Given that the injectors would be mounted low down, it would seem easier to have the additional valve on the top of the tender where it's easy to get to.


----------



## kvom

Having made and attached the two expansion rods and adjusted the piston travel, I was unhappy to see that valve mechanism was locked up. Since it did turn with the right rod in place, I took of the left and tried to see where the problem could be. I found that when the steam chest was not screwed down tight things would move fine, but not with the chest secured. Then I noticed that the valve nut was touching the bottom of its groove. Since it appears that the valve stem and the top of the cylinder face are not precisely parallel, move the valve to the rear was pressing it against the nut and valve stem jamming the works. When I removed the valve and screwed the chest down tightly to the cylinder, the valve mechanism works smoothly.

I won't have time to mill the sides of the nut until after the weekend, but hopefully there's not too many other gotchas in wait.


----------



## kvom

*First run on air ;D*

Having discovered that the valve nut was a bit off center, I milled .03 off the "long" side, reinstalled, and retimed the left sid engine. This time the eccentric rod measured out ~.01" longer, so made another temp rod and installed it. Then I moved the chassis off the surface plate onto the transport "rails", and it rolled along without hanging up anything. That was last night.

Today I installed the front cylinder covers, right running board with quadrant, and the reversing mechanism, and propped the chassis up on two bricks to clear the wheels. After attaching the air line from my mill along with an adjusting valve, it was time to test my work of the past year.

Initially I set the valves to neutral position and turned on the air at 20 psi. Most of the air leakage is between the cylinder and steam chest (there are no gaskets in place as yet). After tightening the steam chest covers a bit I moved the quadrant to full forward and increased the pressure to 65 psi. The engine didn't staer by itself, so I tried moving the drivers by hand, and it sprang to life.  woohoo1

The reverse reach rod is not adjusted properly, so putting the quadrant into full reverse doesn't shift the radius rod fully up, but it does run slowly in that position once I turn the drivers backwards.

I am assuming that the engine will "run in" after a while, allowing it to self-start without my help.

So now it was time for the obligatory video:

http://www.youtube.com/watch?v=VlSsMNs8cE4&feature=youtu.be


----------



## kvom

Today was redo day. The running boards I'd made earlier were HRS from my local redneck steelyard, and didn't finish very well. I therefore ordered two pieces of CRS .25x2.5x36, which have been waiting my attention for a while. These will look a lot better as I didn't need to try to facemill them (definitely a problem for pieces this long, 26.75"). The extra 9" sawed off the ends of each will be used for making the eccentric rods.

I didn't drill holes for anything other than mounting to the chassis plus the quadrant. I won't be attaching the battery "tank", and the holes for attaching the cab need to be re-calculated later. I' also undecided about whether to make the manual cylinder cock linkages. I'll drill the hole(s) for mounting the lubricator when I get it.


----------



## Fuelrush

Sweet! Congratulations! I loved seeing it run slower in reverse! You can see all the rods and links doing their job! Well done!


----------



## doubletop

A big day, well done. Its tight because its been made so well made. The Rob Roy I finished was that tight to start with one of the club members recommended plenty of oil and run it on air for 6 hours or so. It soon freed up and now runs like a sewing machine.

I used Finish Line bike lubricant, because I had some, and it proved to be very effective and once you get the loco running the lube stays where you want it.






The spray can is really useful as it has a long nozzle that you can safely get lube into places you want it, even while the engine is running.

Get it from the bike store

Pete


----------



## steamer

Congrats kvom! Long road to there isn't it.

You'll get there...just keep going. I'm looking forward to the first run on steam....nothing even comes close.

 :bow:

Dave


----------



## Maryak

Onya kvom, :bow: :bow:

Best Regards
Bob


----------



## kvom

This week I drew up the cab sides and front in CAD. The sides I scaled up 2x, and the front I scaled 2x on height and set width equal to the outside edges of the running boards (13.25").

I am wondering what gauge of sheet metal to use. For the 3/4 scale Kozo specifies 1/16 thick, but 1/8 steel seems stiffer than needed. I'm thinking 13ga might be about right. What say you?


----------



## Ed T

The "stiffness" of the material goes up as the cube of the change in thickness (as I recall) so your 13ga material is going to be about 3.75 times stiffer than the 16 ga specified on the plans for the smaller engine. I'm not familiar with the details of the cab design, but if it has any bends they will be much more difficult with the thicker material especially if they're close to an edge. If it's all made up from flat plates, this won't be an issue except for the cutting time. If you're going to cnc it even this will be a small issue. How big is the cab "box"? I'm thinking that 16ga may be just fine unless it's something that you stand or sit on and even then it may be just fine. The bigger issue may be how it's fastened to the loco. These are likely to be the areas of highest loads and, therefore, the areas most likely to distort if the cab is inappropriately loaded. Regardless of thickness, if you're going to CNC the parts there is an opportunity to cut some bend lines part way through the material and then you could probably bend the part up by hand right over the edge of your bench. This would be a really nice way to construct the "box" and would take advantage of the equipment you have to make the job easier and the results better.
Regards,
ET


----------



## kvom

I made the eccentric rods over the past few days, replacing the temporary ones. All of my small ball oilers are two large for these, so I still need to make some brass oil cups (some holes might be enough).


----------



## kvom

After holidays and some family obligations (and some lazy periods), I got back in the shop today. Many of the parts I need to machine next depend on the diameter of the boiler and smokebox that I'm having built, so today I decided to work on the front footplate. I had previously cut the plate itself from some angle iron, so most of the work was making the 4 brackets. First needed to bend them 90 degrees. As it's 1/8" HRS, I used the shop press set up like this:







Then I just needed to mill each of the 4 to the same size and drill holes for mounting. Here's the end result:






Per Kozo's instructions, the assembly will be used as a drill jig to attach it to the underside of the pilot beam.

I went to Metal Supermarkets yesterday to get some 16ga sheet steel to make the sides and front of the cab, and while there found a pieces of 4" round aluminum in the cutoff bin. My plan is to mill the sand dome saddle from it, and then the dome itself from 3" diameter round that I already have. If that works out OK I'm going to do the stack saddle the same way, although I'll need a larger diameter piece of stock for that saddle.


----------



## kvom

Last two days in the shop were used to fabricate the body of the sand box (dome). Scales 2x the dome would have a diameter of 3-1/8", but as I have a stick of 3' aluminum it was made at 89% of scaled.

First step was cutting a 3.5" long slice at the bandsaw.






Next, mount on the lathe, trim the sides, then face, drill and bore the bottom.






The dome is fastened to its base and the boiler via a long screw that connects to a filler plug on the boiler. On the 3/4" version, the boiler is filled via this fitting, so at steam up the dome is removed to unscrew the plug. On my version, a blowdown valve will have a hose fitting. However the boiler will still have either the same plug or a bushing for attaching the dome. The deeper bore in the bottom is necessary to clear the plus or bushing, and the shallower bore is for mating with the base.

Next I reversed the piece in the lathe to face the top and bore for a removeable cab to be made later.






The work was then moved to the CNC mill where it was secured by pockets milled into soft jaws. The spindle was then centered using the top pocket.






The CNC program then mills the top contour radius using .03" steps. The CamBam program I use allows specifying sloped, conves, and concave side profiles in this manner. I'll use a similar program to mill the convex profile for the base, and later for the steam dome and stack base. A CNC lathe would make this easier, of course.






Then, back to the lathe to smooth out the steps with a file and sandpaper. Final sanding and polish will be done with the dome and base screwed together.


----------



## kvom

Continuing on today with the base of the sand dome, I started with a 4x1.2" aluminum drop found at Metal Supermarkets. The saw cuts were very straight, so only a .02" facing cut needed, followed by drilling 1/4 and counterboring.






Mounted on a fixture block on the CNC mill, where the first operation was a boss to fit the dome. The reason the plate is off center in the vise is so that the mounting screw could be accessed from below. I had set X0Y0 there by drilling a 1/4" hole through the plate, so no need to use a center finder. All the cuts on this part are very light.






Check for fit with the dome:






Now mill a concave profile using the same .03 depth increments I used for the dome top.






Then screwed the two together and chucked in the lathe to file and sand the base. Here's the result.






The next operation will be to mill the bottom of the base with a 3-5/16" radius to match the OD of the boiler. That's for another day.


----------



## Groomengineering

Um, I hate being the bearer of possible booboo but if I'm reading the plans right shouldn't the radius be cut in the base before the rim is profiled? Cutting the radius now will remove a big chunk of the flange.  :hDe:

Really enjoying the build by the way. :bow:

Cheers

Jeff


----------



## kvom

Looks like you are correct  Seems that I needed to first do the radius for the front-to-back, then the radius for the boiler.

I guess I'll forge ahead as it is and see how it comes out. I don't have another piece to start over.

It might look OK ;D


----------



## stevehuckss396

That turned out real nice.


----------



## kvom

I continued on with the sand dome base today, not without some issues. Here's my final setup after machining the radius for the boiler shell.






The first try I did with just the center hole and one 1/4" screw. Even as tight as I could get it the piece spun once the mill started at the top. So I drilled two more holes to bold the base securely to the angle plate. Since the raw diameter is 4" I needed to use my longest endmill to reach, and that with only .75" hold in the collet. Given 4-1/8" of stickout. G-wizard computed .05" DOC and .125" radial engagement, meaning 6 passes at each level to avoid deflection of the tool. Ran it at 54 ipm and the milling ran in about 40 minutes.

Removed from the plate and some cleanup filing:






And screwed back onto the dome:






Those edges were sharp, so I cleaned up with a deburring knife.


----------



## kvom

After spending the afternoon at the railroad and having a couple of hours afterwards, I made a start on the cab my machining one of the sides. Stock is 16ga HRS sheet, with fin ished part 9.5x7.25". I had a free piece of Corian that I wanted to test as a fixture plate, so I clamped the steel to the Corian and clamped in the mill vise. Note that the jaws are reversed in order to support a piece this large. The 1/2" holes for the clamp bolts were drilled where the windows will be:






After milling the perimeter with a 1/2" HSS endmill, I used a 7/32 2-flute to cut the windows:






I had to keep moving the clamps around to clear the window area, but finally got both cut.






The other side will be done the same way, but the front has curves and will be done on the CNC mill.


----------



## kvom

After a period of not working in the shop, I managed to make a little progress. The first item is a cap for the sand dome that hides the cavity where the hold-down screw lives. Made from some 1-1/4" brass round.






Having obtained some 1/16" endmills from my friend Ed, I made a first try at the front number plate. I had learned that PRR used their own fonts for these numbers, and that the round plates used a blue background with yellow letters. Another A3 builder (keninrc) supplied me with the PRR font, so it was time to to the CAD/CAM for engraving the plate.

I skipped photography on the steps, but here's the first attempt, from 1/8" sheet stock:






I had a CAM error, so this one will be scrapped after being the test for the paint background. The machining went as follows. First, I used a 1/8" 2-flute square endmill to rough out the cavity. I wasn't sure how deep I wanted to go, so did .003 at a time and finally went .009 deep. Then I used a 1/16" 2-flute square to further mill the number (the 8 is finished at this step.) Then the 5 and 6s were to get finished via a 1/16" ball mill at .005" deep. However, I didn't give this a new tool number, so no tool change and the square endmill kept running. Meh!

I gave it a brief surface polish with some 600-grit paper, and have spray-painted it with rustoleum. Once the paint dries I'll sand off the paint from the letters and border. If all goes well, I'll try to find some blue paint of about the right color and make another.


----------



## kvom

Today I started to draw the front and back plates of the smokebox saddle, since I obtained a suitable piece of 1/4' steel plate to make them. Then I looked more closely at the drawings, and realized that my conception of the saddle was wrong. On many models the saddle is part of the cylinder casting(s), and it serves as the support for the smokebox. However, on this model the saddle is supported by the smokebox. The support for the smokebox is provided by the vertical part of the tee containing the steam supply and exhaust channels.

Since my tee was not milled with the vertical arm, I will need to make a support piece through which the exhaust will flow. This piece will need to screw into the tee's exhaust port (threaded 1/2-20) and be the correct length to just reach the bottom of the smokebox. The top end of this support will be threaded to accept the exhaust nozzle. The nozzle will thus act as a screw to fasten the smokebox, exhaust extension, and tee securely together. The saddle itself just hangs from 4 screws that attach it to the smokebox.

Since I won't know precisely the distance between the tee and smokebox, I can't make the saddle front and back plates. I also can't finish the exhaust extension, although I can partially complete it. OTOH, I can make the exhaust nozzle and rough out the petticoat.


----------



## stevehuckss396

The plate looks cool. It seems the cutting ended before finishing. Something bad happen?


----------



## kvom

stevehuckss396  said:
			
		

> The plate looks cool. It seems the cutting ended before finishing. Something bad happen?



I started by machining the main pocket with a 1/8" endmill, leaving the numbers as islands. I increased the depth by .003' per pass until .009, at which point I decided it seemed deep enough. The next op was using a 1/16 flat endmill to profile the numbers. This was at .003 (still experimenting). This finished the '8', but wasn't small enough to get into the upper parts of the 5 and 6. So the plan was to use a 1/16 ball endmill at .005.

My booboo was not changing the tool# for the last tool, so Cambam didn't generate a toolchange code, and the flat endmill then went into the numbers thinning their widths. For a remake, all three tools will have a target depth of .005.

The outer diameter was cut using 3 tabs, which were easily filed away afterwards.


----------



## kvom

Being a rainy day gave some shop time. The first job was to remake the number plate. The blue color was the closest rattle can I could find to a picture I'd seen of a PRR round plate.






I made a start on the smokebox support member. 1" steel rod drilled 1/4" through, then threaded 1/2-20 on one end.






With the support show in place. The final length will depend on the smokebox bottom when set level.


----------



## kvom

I will not be using the collar to attach the stack to the smokebox, but rather will have a separate petticoat. After some reading on Chaski, I watched Dave Sciavi's (trainman4602) two videos on smokebox design. The 3 "principles" exposed are:

1) blast nozzle diameter is 1/7 of cylinder bore diameter; in this case it's .25"
2) Position of the nozzle wrt the stack top is that both lie on a 7-1 cone
3) Position of the petticoat wrt nozzle is that both lie on a 3-1 one.

Given that my boiler OD is 7.5" and that the stack is scaled from Kozo's drawing, I first drew the smokebox with the stack together (using Draftsight as CAD). Next I drew the 7-1 cone from the top off the stack, and determined the position in the smokebox where the cone's width is .25". This fixes the top of the nozzle.

Then I drew the 3-1 cone from the edges of the nozzle. Assuming that the petticoat would be made from a steel tube with a 1" ID and 1.5" OD, I determined where the cone was 1" wide. With the entry flared .25" the position of the petticoat is fixed.

The result is the attached drawing. The dimensions differ quite a bit from Kozo's scaled dimensions.


----------



## Path

Kvom,

Nice looking engine :bow:... been following along for some time ... great work. 
Hope to get back to my 3/4 sometime soon.


Pat


----------



## kvom

Not wanting to let the entire Christmas weekend pass by without some shop time, I decided to have a go at the headlight bracket. I took a little different tack than Kozo:






Feet are CNCed to match the smokebox OD from 1/4" sheet, with the top from 1/8".

The screw heads will probably be hidden when installed, unless I decide to paint the whole thing black. Per the plans, the feet would be attached to the smokebox by 4 screws angled in. I'm thinking instead to just use two screws from the centers of the feet, which will be easier to locate accurately.


----------



## kvom

I worked on the smokestack the past two days, with around 14 hours shop time invested in it. I started with a 6.8" long piece of 3" round 6061 and ended up with this:






plus a huge pile of swarf stringers all over the shop floor.

The bore is tapered 4 degrees included angle, and to get the stock secure enough in the lathe (I haven't a steady rest), I bored soft jaws. After drilling through with my largest drill bit (15/16), I then bored straight to the minimum size of 1.375. Unfortunately my longest boring bar only reaches 4.5", so I was obliged to bore the taper from both ends. Since this means swinging the taper attachment to the opposite side (hard to get an exact angle match), and since there was a bit of runout at the small end, I ended up with a small ridge on the inside, but hopefully not enough to matter.

I didn't take pics during the turning, but here's a pic of my setup for turning the outside taper (2 degrees included). This was a lot easier.






The right end is supported with my home-brew bull center.


----------



## kvom

Today's task was to start the two "handholds" that attach to the ends of the front pilot beam. Those building the slantback tender would male 4 of these as there would two on the tender's foot plate.

Starting with 3 pieces of .75" round 12L14, I faced and tapped each 3/8-16 as shown here:






The piece on the right is a fixture to be held in a 5C collet. I screwed in a bolt and cut off the head:






Then for turning the setup is like this, with the work screwed onto the fixture.






After turning, the collet and work are placed in a hex collet block to mill the bottom section to fit a 9/16' wrench.






One completed item shown where it will be attached to the pilot beam.






The second one will have to wait for the next shop session.


----------



## ozzie46

Looking good Kirk. I bet she's getting a little hefty by now. ;D ;D

 Ron


----------



## kvom

Just back tonight from Cabin Fever with thealmost completed boiler. I need to supply a drawing for the steam dome, which Wayne Godschall will ship along with the safeties. I drove up Thursday, attended the auction on Friday, looked at models on Saturday and bought stuff, then headed home this morning. I'll post pics once I get the car unloaded.

Stuff bought for the engine at the show:

1) From Locoparts: blowdown valves, boiler check valves, stancions, and lubricator check valves. I was going to get a water glass assembly, but still need to figure where to drill and tap the backhead for the glass, and then will know the size glass I need.

2) From Rail Supply: a nice casting set for a bell and mount.

3) From PMR: whistle valve, some 5/16 brass pipe, and a tree of elbows.

The loco will diverge from the Kozo design in a few ways, based on discussions this week and the boiler design:

1) Rather than a single lubricator feed through the bottom of the tee, I'll be using a dual-port lubricator with steam oil fed in through the steam chest cover as per the prototype.

2) The throttle will be located in the smokebox rather than the steam dome, with the control rod through a longitudinal stay.

3) I won't be using a snifter valve, being advised that for this size loco they are normally not needed.


----------



## kvom

Today I mounted the boiler inside the frame for a test fit.







I put some metal bars under the barrel and across the frame to get the boiler barrel approximately level with the firebox bottom sitting on the grate supports. Using a digital level the barrel is about 1 degree out of level with the frame top.

Next I wanted to find the height of the boiler's centerline above the top surface of the tee. I used a height gauge to measure the top plus a micrometer for the diameter and did a bit of arithmetic. Next I measured the OD of the smokebox using the DRO on the mill. Combining the two measurements allows computation of the length of the exhaust tube needed to support the smokebox and attached boiler to the tee.






Notice that there are 18 3/4" copper flues vs. the 7 1" flues that Kozo shows. So my total draft area is 8 inches square vs 5.5.

Another difference is that the smokebox is a slip fit over the front of the end of the boiler and will be just sealed with high-temp RTV, vs. being clamped as Kozo does. This allows expansion of both when hot.


----------



## Path

This is coming together real nice ... thanks for sharing. 


Pat H.


----------



## kvom

Today I had a couple of hours to start on the smokebox. Raw material is a steel tube 7.3" in diameter and 15" long. I measured the ID as accurately as possible using edgefinder and DRO on the Bridgeport. Then I mounted my rotab on the mill for the first time in over 2 years. I centered it under the spindle with a DI, and then milled the outer ends of the soft jaws to match the tube's ID:






I then mounted the tube and turned the rotab 90 degrees in spot drilling 4 holes that will be tapped 5-40 and will be used to secure the smokebox door. With the rotab, chuck, tube, and drill chuck, I didn't have enough Z space to drill the holes, so I did this with the tube sitting on the vise.






Now I mounted the rotab vertically and squared to the table, then chucked the tube. I used the screws and a square to orient the tube and with an edgefinder to find the X axis centerline.






Finally drilled some "starter" holes for the smokestack and exhaust, plus two stanchions. That's as far as I wanted to go for now. I want to finish the smokestack base plus the petticoat so that they'll all get attached together. Those plus the exhaust nozzle are my lathe projects for the next shop sessions.


----------



## syrtismajor

Wow, that is a thick walled smoke box. Is the boiler also steel? If so your engine will be a mini-monster! Do you have any idea how heavy it will be when completed?


----------



## kvom

Steam engines work better the heavier they are. The power of steam is such that the wheels will slip unless there is enough weight on them when pulling a load. Some builders in this scale use lead sheet for lagging around the boiler to increase traction. I'm guessing that when complete and holding water, the engine will be at around 200 lbs.


----------



## syrtismajor

I've read stories about engines being loaded with slabs of lead to aid in traction, especially with the smaller gauge engines. That is one thing I will eventually have to think about doing the same on my engine as the design is apparently known for being light on its feet.


----------



## kvom

Today's small parts took more time than I care to admit, but at least there's progress. For the petticoat, I started with a piece of 2" round 12L14 steel. The first operation was to set up on the CNC mill to machine the end to match the ID of the smokebox.






Tested for fit:






Then onto the lathe to be drilled, and then bored to match the diameter of the smokestack. I have to give props to the new DTM boring bar and AXA holder I picked up at Cabin Fever. Perfect fit on the QCTP and very solid.






The brass item to the right is a roughed out exhaust nozzle. I need to make a bottom plate for the smokebox where the nozzle will set; the rounded end will be threaded and pass through the bottom of the smoke box to screw into the support bar. Hopefully I can make the plate next time out and get the smokebox sitting on the chassis for the first time.


----------



## Maryak

kvom  said:
			
		

> Steam engines work better the heavier they are. The power of steam is such that the wheels will slip unless there is enough weight on them when pulling a load. Some builders in this scale use lead sheet for lagging around the boiler to increase traction. I'm guessing that when complete and holding water, the engine will be at around 200 lbs.



Kvom,

Is there provision for sand boxes in your design ???

Full size locos used them to drop sand on the rails to help stop wheel slip, particularly on wet rails, (rain, snow, dew and all the other slippery slimey things that lurk on the track.).

Best Regards
Bob


----------



## kvom

There's a dummy sand box. Pics of the fabrication start on pg. 17 of this thread. I'll need to remachine the radius on the base a bit to match the boiler cover.

Working sanders don't work well at this scale.


----------



## kvom

Today's target was to finish the exhaust nozzle and smokebox support and see how the smokebox sits on the chassis. After drilling and tapping the support bar 1/2-20, I single-pointed the bottom of the nozzle. Good fit:






I then did a quick CNC job to mill the smokebox ID radius onto a small piece of CRS, which I then drilled. This piece allows the nozzle to screw down flat inside the smokebox and provide a seal. Then I screwed all 4 parts together:






With the nozzle screwed down tight the smokebox sit quick firmly without rocking. It can obviously swivel side to side, but that will be eliminated when the steam pipe and saddle are added. The height looks to need adjusting. I think that will wait for later since I may need to adjust the grate supports to account for uneven welds on the bottom of the firebox wall.

With the boiler sitting in place, it's clear that any chassis work/rework needs to be done before trying to steam up as there is very limited access underneath. So since I have a laundry list of stuff to redo or fix, I'm planning to work on the chassis, smokebox, and boiler separately, not joining them until all the separate issues are addressed. I do need to tear down the chassis for at least the following:

1) Drill/bore hole in right side frame for blowdown valve access.

2) Drill and tap cylinders for cylinder cocks (I'm going to use some automatic ones at least initially).

3) Separate wheels from axles to address axle box oiling and replace one axle with a broken drill bit, then re-quarter drivers.

4) Finish and install foot brake system.

5) Add bracket/link on one eccentric trunion to drive lubricator

So I need to not get too "excited" about the boiler for now. The smokebox still needs the stack base made, and the stack/base/petticoat attachment figured out.

Lots to do


----------



## kvom

Today's shop session involved reducing 2 pounds of aluminum into a two ounce part and lots of swarf. This is for the base of the smokestack.

Started with some 3" round, faced both ends on the lathe, drilled and counterbored for two 1/4" mounting screws, and attached to a fixture plate.






Lacking a CNC lathe, the next best thing is milling the outer profile as a series of .003" cuts in Z.






Now mount on the lathe and use file and sandpaper to smooth out the layer-cake.






Next, drill and counter-bore two more holes to mount on the angle plate; then place the plate on the mill,






And mill the bottom face to match the curve of the smokebox.






Looks good so far:






Next, bore to accept the smokestack. I was shooting for a press fit, but overshot and got a tight sliding fit.






Part off, and assemble for another check.


----------



## kvom

Yesterday I decided unpack the pair of tender trucks that I purchased at Cabin Fever and then see about mounting them on the tender body. I discovered that the tender's bolsters were two long, and would hit the top of the brake shoes.






After seeking and receiving some good advice on Chaski, I decided to shorten them and add two mounting holes to replace those that would be cut away. Since the distance between the truck's center and the corner of the brake shoe was 4", I decided to mill the ends with a 3.75" radius via CNC. Here's the result:






I needed to drill and tap 3/8-16 in the tender bolster pivot to match the truck's kingpin, and after screwing the bolster back on the tender frame, it was straightforward to screw the trucks onto the bolster.






With the tender upright, I could check the coupler height; it's dead on for the IBLS standard. After towing it around the club track in the next couple of weeks to verify tracking, I'll need to do some more work on the tender before painting. The main task is adding a second water leg valve in order to support two injectors.






While I have both engine chassis and tender on their wheels, I'll measure to see how to make the drawbar to fit the two.


----------



## syrtismajor

The tender looks as though it will fit the A3 perfectly! Have you lined the loco and tender together yet to:

A/ Get a good idea of the final 'look' of the engine?
B/ Get a photo to show the boards how impressive your future hauling machine looks?
C/ Sat behind it and pretended you're driving round a railway whilst making whistling noises? ;D

Hope to see more soon!


----------



## kvom

Before tearing down the chassis for some paint and fixes, I need to finish the brake system and test it. With a short shop session today before the super bowl, I decided to make the brake rod and its "fork ends" (pg. 214, fig. 3-9).

Having no 3/16 rod handy, I made the rod from 1/4 rod and turned down the ends to .190 for threading 10-24. The ends were profiled and slotted on the CNC mill from 1/2" square HRS, and then the ends drilled and tapped on the manual mill. Couldn't find a 10-24 nut for the jam nut though. I'd previously made the brake beam lever, but looking at it a year later I've decided it's crappy and will remake it. I have acquired a small metal bender that can make accurate bends in flat stock, so I'll be able to use that on the lever as well as the foot pedal.






We had a run day at the club yesterday where I was intending to tow the tender around to check its tracking. But since my hoist is occupied by the Jeep, and since the tender is now too heavy for me to lift now that it has trucks, I left that for another time. In the meantime I'm learning a lot about how to plumb the boiler from looking at other members' locos. I ordered some brass bar that can be made into the turret at some point. I also have on order some round-head drive screws that will become fake rivets around the ends of the smokebox.


----------



## steamer

Looking great KVOM! :bow:

Question....what's the primer your using in the photo...is it for copper/brass specifically?

I've never had good luck painting these metals.....always comes off easy.


Dave


----------



## kvom

Assuming you're referring to the tender, it's all steel. I bought the tender body already primed.


----------



## Paolo

Dear Kwom
You are doing a real masterpiece!! I'm really interested on you project!!!
Best regards
Paolo


----------



## kvom

Having seen quite a number of locos in "real life" since I started, I am a little ashamed of my puny efforts in comparison. I saw your thread start Paolo, and those drivers are great.

Lately I haven't been doing much for progress, other than odds and ends. I started making the fire door this week and still have a couple of pieces to go to finish it.


----------



## steamer

OK Kvom....I seem to remember the plans call for some copper smithing on the tender, and I just assumed.

Looking good!  Stick with her , your getting near. :bow:

Dave


----------



## kvom

I didn't feel like doing any machining/fabrication today, so decided not to put off disassembling the chassis any longer. Now it's down to frame, drivers, and cylinders. Next step is to position boiler level on the firebox supports to determine the proper height for the smokebox supports. Since my lift has been occupied by the Jeep for the past 2 weeks, and likely another week to go, at least I can "probably" lift it down to the floor.

Once that's done it's coming apart the rest of the way. I need to bore a frame hole for the right side blowdown valve, paint the side frames, drill/tap the cylinders for cocks, and then paint the cylinders and steam chests. I will also drill and tap the steam chest covers for the lubricator check valves.






I also took the tender tank off the frame preparatory to painting. Now it's also in pieces that I can lift. I started painting the three removable covers, but will need more paint to cover all the rest. Paint is Valspar tractor paint.


----------



## kvom

Today I painted the frame and tank of the tender (separately). Here's the tank:







I found that the beading around the upper edges are indeed brass, so I'm not sure how well the paint will adhere. It will get a second coat tomorrow.

Yesterday I took the boiler over to a fellow club member's house where he Tig'ed the ring for the firebox door onto the boiler. He also tig'ed the brake lever parts where I'd had difficulty attaching them with silver solder:






Finally, I bought a spray basket strainer at Tractor Supply. It has an 80-mesh strainer as shown here:






Since I'm going to be using injectors, the tender water supply needs to be strained to prevent small particles in the water from clogging the injector. My tender is not well suited for putting a well in the bottom, so I was planning to use this strainer inside the tank to connect to the valves via tubing. However, the size and design of the plastic enclosure makes this a no-go. So I plan to make caps for the ends of the strainer basket and connect both valves via barbs and tubing.


----------



## kvom

Today did touchup on the tender paint, and then made this using the strainer basket:






The two plugs on each end were tapered to ensure a nice tight fit. This filter will be connected by plastic tubes to the two water valves.


----------



## kvom

I took the tender to the club today for a short test on the rails. I don't have a seat yet, but sitting on the rear cover with feet on the footrests is reasonably comfortable, and should improve with a seat and more height. Since the engine has a footbrake pedal, I have yet to see where the right foot would best be placed when running.

The good news is that the trucks tracked well while being pulled/pushed with a fellow-member's diesel. The bad is that there is excessive side rock, and I will need to add some pads to the tender's bolsters. Being in bright sun also showed up lots of spots that need another paint layer.

This weekend I started preparing the bushings in the boiler for the feed water checks and glass/pressure gauges, and tonight I finished up ready for welding. This technique, which a fellow club member recommends, is best done early in the build where they can be welded on both sides of the pipe. The bushings are made from SS high-pressure couplings purchased from the hardware. In this case, the couplings are 3/4" diameter, ~2" long, and threaded 1/4 NPT on each end. Each coupling yields two bushings when cut in two. I cut them on the lathe with a 1/16 parting tool using lots of cutting oil.

Another reason to weld everything early on is the difficulty of securing a finished boiler to the mill table. here's my setup for the feed water holes:






The tube is resting on two largish v-blocks with the jack supporting the firebox. A square against the steam dome plate makes the boiler as close to sideways as I could get. The it's drill out to 11/16, and bore to ~.730. Then countersink about halfway to provide space for weld filler.






The bushing measured .747, and as dropping it through the hole would be both embarrassing and a PITA, I necked down the bushing part way until there is a tight fit.






The other side was done the same way after rotating the tube on the v-blocks and re-clamping. The third bushing will supply steam to the water glass and pressure gauge. Kozo's design connects both to the turret, and I've been advised that this is poor practice at larger scales, because any valve open in the turret drops pressure and caused both gauges to fluctuate. The same drilling/boring/countersinking was done for this with a different, somewhat "jury-rigged" setup:











I still need to drill and tap a hole in the backhead for the water gauge. I was able to use the top bushing hole to measure the depth of the crown sheet as 2.4". Since I want the bottom of the glass to be .5" above, that will be 1.9" from the top of the tube. And since the glass I will be using has its connection 1.25" below the glass, I can drill the hole anywhere in the backhead 3.15" below the top. I'll have to wait and see how far to the side I want the glass at some point. Since I don't have a 90 degree head for the Bridgeport, I'll have to mount the boiler with the tube hanging vertically off the back of the table, and turn/extent the ram to reach the desired spot.


----------



## kvom

While waiting for my buddy to weld up the bushings, I proceeded to try to muddle along and see if i could get the smokebox height to match the boiler's when mounted to the frame supports. Since the smokebox is supported by the tee, the top of the tee will be the reference datum. Since the tee is connected to the frame by the cylinders, which would be in the way, I machined a couple of support plates using the cylinders' hole pattern. This way I can hold the tee in its proper position without the cylinders:






Now I rmoved the wheels and axles, placed the frame on the surface plate, and used my electronic level to measure the top of the tee:






Now with the boiler in place, I added some supports to get the same measurement, using the smokebox plate as a datum:






Now by measuring the top of the boiler tube from the tee, and knowing both the boiler and smokebox ODs, I calculated the necessary length of the smokebox support. It was less than I made it originally, so I faced it off in the lathe and did a quick fit:






I still need to tap the support and secure the smokebox with the nozzle. Since the support screws into the tee, I can adjust the smokebox height a bit once it's all together.


----------



## zeeprogrammer

Another thread I'm happy to find still going after my hiatus!
Looking great!
I've got the books and the dream and learning a lot here.

I noticed you were at Cabin Fever. Too bad I couldn't make it this year.
That was some trip you took!


----------



## steamer

Coming together nice KVOM!

Take your time on the boiler....it's time well spent.

Dave


----------



## kvom

A lot of little jobs done since the last post. My friend welded the bushings in the boiler and I received the steam dome and safeties from my boilermaker. In the meantime I tore down the frame completely and painted the side frames with Valspar tractor and implement paint after a coat of Valspar primer. I've also painted the steam chests.

Before painting I also drilled a hole in the right side frame for the blowdown valve (Kozo has only one on the left for the 3/4 scale model). I think that for 1.5 scale builders it's probably better to drill these holes after the boiler is finished, esp. if you're using a steel boiler. I found that the hole center needed to be a bit higher than per plan since there is weldment on the bottom of the firebox.

Here's a photo of the boiler with the steam dome and safeties, along with the hunk of aluminum that might become the base of the dome cover eventually.






The dome canister sits here held on by screws. 






I am still undecided as to the throttle setup. The boiler was made to plan, but I've been advised that the needle valve Kozo shows for 3/4 scale is not best for larger scales, so I will be using a ball valve. The first option is for the valve to be vertical in the dome, and will need two elbows to position it in the center. I spec'ed the cylinder to be large enough to accomodate this setup. Then there are two possibilities:

1) have the valve stem exit the side of the dome and have the throttle be an exterior push-pull rod.
2) have the vale stem exit the back of the dome and the throttle will be an arm that rotates.

The final possibilitity may be to cut out the dry pipe from the front tube sheet, cut out the center of the dome to allow the valve to be inside the boiler, and run the throttle rod back through the backhead. Hopefully the brain trust at my club will come up with the best option.

The final bit done is to drill and tap holes for the cylinder cocks. Rather than make the fairly complex linkage Kozo designed, I decided to use a set of automatic cocks from Jesse Banning at JdLocomotive Works. These are threaded 1/8 NPT rather than the straight threads in Kozo's plans. If you inspect fig. 14-1 on p. 83, you see that the holes that actually enter the cylinder bore are angled. I have been advised that the angle is relatively unimportant as long as the piston rings don't pass over the holes; however, the closer the holes are to the end of the bore the better. I drew the holes in CAD to determine the angle, which seems to be 16 degrees, but I'm going to double check before drilling. These holes with be 1/8" diameter.






Then I can do some finish filing on the outside of the cylinders and paint them.


----------



## kvom

A few months ago I started to drill oil passages in the axles so that the axle boxes could be lubricated by ball oilers in the end of the axles. Then I had the drill bit break in the second side hole, so abandoned going further. I was pretty sure I would need to make new axles, since drilling them before the drivers were in place would be a lot easier. Before doing so, I decided to make one more try with the current axles.

Since then I acquired a small machinist vise, and this allows me to hold the axles/driver assembly above the mill vise. So with the following setup, a new 3/32 cobalt drill bit, and careful pecking, I drilled the lateral holes in one axle successfully.






I think I have figured out a way to drill the lengthwise holes as well. On the other axle, the broken bit is still lodged in the hole, so I am hoping that a carbide bit will be able to clear it out of the way.


----------



## kvom

Using the same small vise and a machinist's jack, I got this setup to enable drilling the lengthwise oil passages in the rear axle:






When trying the front axle on the side where the drill broke previously, I found it very hard to make any penetration. I suspect that the steel has hardened. When quartering last year, I had to remove the wheel and reposition it, and needed a torch to break the loctite seal. It never got red-hot nor was quenched, so I wouldn't have thought it would have gotten hard. I can get somewhere with carbide, so will try again tomorrow.


----------



## kvom

I set the axle oiler problem aside today and drilled the holes from the cocks into the cylinder bore, then finshed some cleanup of the outsides via some milling and sanding. Then I attached the steam chest covers and the mounting plates I made to align the tee to the valve and tee surfaces and applied painters tape to the ends. Thus all surfaces that are not to be painted are covered. With a couple of plugs in the threaded cylinder cock holes the cylinders are ready to be painted.

I'm going offroading with the Jeep tomorrow, so no more work until Sunday at the earliest.


----------



## kvom

I got the cylinders painted and the cocks installed. Also painted the steam dome and its cover with high-temp paint.






Then drilled and tapped the steam chest covers to install the lubricator check valves.






Saturday is hydro-test day at the club, so today I carried the boiler over there; I have a conflict in the morning, so hopefully it can be hydro'ed without me, or wait until I can get there.


----------



## zeeprogrammer

Good luck on the hydro test.
Enjoying the thread.


----------



## kvom

I bit the bullet today and removed the front drivers from their axle. Since Loctite 620 frees up above 450F, I put the assembly in the oven at 500F for about 15 minutes. Then I used the shop press to separate the drivers from the axle. It took a fair amount of pressure before the axle let go with a "bang". On the other hand, the crank pins pressed out very easily. Then I turned a new axle with oiler passages:






My little bottle of 620 has gone missing in the shop, so after looking for it for half an hour I ordered a new bottle from McMaster. It should get here tomorrow so that I can re-quarter the drivers.

The only other little job I got done (finally) was drill some 1/16" oil holes in the eccentric rods.


----------



## kvom

This morning I re-quartered the front drivers using a method similar to how I did it last year at school. Now that I have some v-blocks with clamps I could do them at home. Here's the setup on the surface plate:






The driver on the left was fastened to the axle a couple of days ago. The two aluminum "fixtures" were turned so that the smaller diameter fits the crank pin holes, and the larger diameter mathches the axle. First I set the left driver with the crank vertical by matching the axle and fixture using a precision square. The v-block clamps are then secured. Next I measure the height of the right axle with a height gauge, subtract the axle diameter, and assemble a stack of gauge blocks equal to that amount. This stack then just fits under the axle. The longer aluminum rod held in the small vise is just the desired separation between the drivers.

So now the tricky part requiring some coordination: spread some green 620 Loctite inside the bore of the right driver, then slide the driver onto the axle so that it touches the end of the aluminum spacer rod, and then rotate so that the fixture rod touches the top of the gauge block stack. The Loctite gives you only a few seconds before it tightens up, so I did more a few dry run rehearsals.

I'll check my work in a day or so when I reassemble the frame; if all's well the two pairs of drivers attached with the side rods should turn freely again w/o binding. Then I'll secure the crank pins again with Loctite.

The "technique" is not all that different from what Kozo specifies, except that I could compensate for whatever axle diameter I chose.

I had ordered several boxes of drive screws to be used as fake rivets. After installing them into some scrap, I decided that the #4 screws would look best along the ends of the smokebox. I decided on 10 degrees separation as giving a decent look and making it easy to operate the rotab. Before the end of the session I managed to drill the rear holes and spot drill the front:






These screws use a #37 (.104") hole. I made a drift from some brass rod with a hemispherical cavity that I created with a 1/4 ball end mill. These should get installed next shop session. I had intended to bore the smokestack opening as well, but this setup isn't rigid enough.


----------



## smfr

Very interesting build, with lots of solutions to tricky problems! I'm following along with interest!

Simon


----------



## kvom

Continuing to work on the smokebox. Drilled and then bored the smoke hole to match the stack ID:






After finishing the "rivet" holes, installed the drive screws around the front and back perimeter. It should look better once the heads are painted to match the shell.






Couldn't resist a poser shot with the yet to be attached stack and headlight base:


----------



## Paolo

Dear kvom
I'm really fascinated by your work!!!


----------



## kvom

Slow progress over the past week as life gets in the way and my mill was out of commission for a few days remaking the drawbar threads.

Managed to cut out the sides of the ash pan - 16 ga sheet. I'm going to make the bottom and front side from 1/8.






My solution to excess side play in the tender bolsters is these four round "pads", one on each side of each bolster. .75" diameter and countersunk, the side-to-side wobble is now the recommended 1/16 inch.


----------



## doubletop

kvom  said:
			
		

> My solution to excess side play in the tender bolsters is these four round "pads", one on each side of each bolster. .75" diameter and countersunk, the side-to-side wobble is now the recommended 1/16 inch.



Could it be that those recesses were originally for nylon or Teflon pads?

Pete


----------



## kvom

The tender was made quite some time ago, and obviously was intended for a different set of trucks.  I doubt any truck pads would be narrow enough to contact the recesses. It seems to be that the bolster was fabricated just to give enough clearance and to use minimal material.


----------



## zeeprogrammer

Nice shots with the smokebox!
The rivets look great.


----------



## Lesmo

Hi Kirk 

Just caught up with your build, that certainly is a lot of painstaking work you have put in there, and it certainly is coming along well, further advanced than I expected. I can see what you mean now about needing a large mill to be able to tackle a project of this size. Looking forward to the video of it steaming down the track resplendent in its new livery.
How much more time do recon you have until that proud moment..

Les


----------



## kvom

My goal was to be in steam 2 years from start, so that would be November this year. I have slowed down a bit lately as other things take up time once the weather turns nicer. I don't have to everything done to steam up the first time. So the cab, boiler jacket, smokebox cover, sand dome, bell, light, handrails, and whistle are optional to run on the track. That said, I want to finish/install everything that would require a lot of disassembly to add.

I got the 1/8" HRS for the bottom and front side of the ash pan. Milled them to size and MIG welded them together (if you call my booger welds "welding). Then attached the sides with JB weld. The second side is curing now. Once set I'll paint it and take a pic. This isn't a visible part so I can't say I took a lot of care making it look good. Given that the pan attaches to the boiler firebox support, removing it once the boiler is in place would be a bit of a PITA. Kozo's design would require removing the supports, so I made a small modification. First, I tapped the pin holes in the supports 1/4-20, and then bought a pair of hex head 1/4-20x1/2" bolts. Next I took a piece of 1/2" aluminum rod 1/2" long and drilled/tapped it on the lathe. After screwing the bolt into this jig, I was able to turn the end 1/4" of threads down to 1/8":







Here's the result:






And installed in the supports:






If I need to remove the ash pan in the future, I can do so my removed the two screws and dropping the pan.

I started to reassemble the frame, and then to check the new quartering of the front axle. At that point I discovered I had quartered it backwards relative to the rear axle. Nothing to do but heat up on wheel, press it off, and redo the setup with the correct orientation. Compare this picture with the one show previously:






Now the right, horizontal, crank pin is rotated forward rather than back. Once it cures I'll mount to the frame and check it (with crossed fingers).


----------



## kvom

Some more work on the smokebox today: drilling holes for mounting the "accessories". The inner, countersunk holes are for the bolts to hold the petticoat, while the outer threaded holes are for mounting the base of the smokestack. Two lateral holes are for securing the base of the headlight.






The smokebox is now finished except for the holes for mounting the saddle.

I also painted and installed the ash pan on the frame:






And finally, my quartering seems fine as the side rods turn smoothly with the drivers, so the crank pins are now loctited in place.


----------



## kvom

A bit more progress over the past few days. I used some commercial blackening solution on the aluminum brake shoes, so these won't stand out so much once installed. It's a thin coating so scratches will show through. We'll see how well it holds up.






Then started work on remaking the guide yokes in steel, as I foresee some issues with the brass ones. Starting with some 4"x5/8" HRS bar, I machined two blanks after quite a lot of work. Then the first one was milled as shown.






I was experimenting with the concept of "high speed machining" on the CNC mill, where the idea is to take many passes with small engagement and higher feed rates. The job doesn't get done much faster, if at all, but it's easier on the tooling. Unfortunately when doing the same on the second piece the endmill moved in the R8 collet and cut too deep. Seems larger carbide EMs don't hold that well in R8 collets. I'll redo it using a HSS endmill, although that will be half as fast.

Next all the holes are drilled, and the slot for the radius rod cut.






I then screwed the work to a piece of aluminum in order to cut the profile. I also used a clamp for extra security. The final result:






The second one will be the same except being a mirror image.


----------



## kvom

Spent the day making the right side guide yoke:






Still need to drill and tap the mounting holes for the walk boards and mill a clearance slot for the rear wheel flanges.


----------



## stevehuckss396

I don't post much in this thread but I wanted to let you know that i'm still following along and enjoying the heck out of this build. Everything looks great as usual.


----------



## kvom

Thanks for looking in, Steve.

In order to capture the "adjustments" I'd made to the brass yokes, I screwed the old and new together:






Then it was easy to mill the steel yokes until they matched the brass. Then I installed the yokes and tie plate plus the running boards on the rear supports. The mounting holes on top of the yokes were then marked with a transfer punch, drilled, and tapped.






The yokes are now painted and ready for installation when the time arrives.

Before any further reassembly, I wanted to get the brakes installed and checked out, since they need to go in from underneath the frame. So today I made the foot pedal. Kozo just specifies some 3/16" bar bent to shape, but I decided to make it in two pieces. If I want the part where the sole rests to be wider, it'll be easy to modify.


----------



## kvom

Finished work on the brake system and got it installed:






Rather than a screw for securing the removable foot pedal I turned a pin; seems simpler. I didn't offset the front lever arm as per the plans, but even so there's no interferene on the brake rod. If there were making the fork end's slot offset seems more precise than trying to bend the lever.


----------



## kvom

Another item that has to be built and installed before doing much else is the smokebox saddle. This piece is purely decorative as it does not support the smokebox and is needed to resemble the prototype. In the 3/4" version it's made from 1/8" brass and some copper sheet that can be bent to match the smokebox radius. Mine will be made from steel. The part that attaches to the smokebox is part CNC-machined and part manual. Here's the raw stock:
CRS 6"x4.25x1.






The smokebox mounting surface was CNCed as shown to match. I used a 5/8" diameter 4-flute HSS endmill with 2.25" flutes. Lots of chatter! It took over an hour of machine time to do half.






Some more CNC and manual work and I got this:






Front and back plates will be made from 1/4" CRS, and the sides of 16 gauge.


----------



## kvom

Next steps in fabricating the saddle:

After milling the central pocket for passage of the steam and exhaust, plus the 4 mounting holes, I mounted the saddle top and the smokebox on the tee. To ensure that the tee is in the runtime position I needed to remount the cylinders. Then I was able to position the saddle top and secure it to the smokebox with a clamp. The saddle is designed to be centered fore and aft on the cylinders.






Then I removed the smokebox with the saddle top still clamped to it, marked the mounting hole positions with a transfer punch, and drilled the smokebox. Show here mounted using 8-32 screws:






Now I was able to measure to determine the distance between the bottom of the smokebox and the top of the frame rails so that I could draw the saddle front and back plates in CAD. The goal is for the curve in the plates to end up flush with the frame top. To check, I used the Draftsight feature that allows printing a drawing actual size. I cut it out and was able to confirm the fit before cutting metal:


----------



## Sparticusrye

Excellent progress Kvom. Looking forward to seeing you loco unde it's own steam.


----------



## kvom

A little more progress after milling the front and back plates of the saddle. I clamped them in the mill vise to position the smokebox so that I could make the screw hole in the top.






Then drilled and tap the holes in the top and screwed the 3 pieces together:






Then a test fit with the boiler.






I still need to fab the sides and bottom, do a bit more fitting, and then paint.


----------



## Lesmo

Hi Kirk

Your build is coming along by leaps and bounds and looking really smooth, you are certainly doing some nice work here, I bet the CnC mill is a great help with some of those curved parts. This sure is a complex long haul compared to the little elmer and I dont think I will be attempting to follow you on this one. More power to your elbow.

Les


----------



## kvom

A bit more smokebox progress made over the past few days:

Along with the boiler and smokebox tube I got a very nice and realistic smokebox door. It even has hinges and will open if the 10 dogs are unbolted around the rim. As with most of the engines at my club, mine will have the door attached to the front of the smokebox with 4 screws located at the cardinal positions. To make for more realism, I decided to add 16 more dummy bolts around the periphery. Here's the door frame with the dummy screws shown with the door itself. The screws are scaled 5-40 from Ameriican Model Engineering,






Since the screws are 1/4" long (shortest available from AME), they protrude through the frame's flange. This would keep the door from seating properly.






So I mounted the frame on the lathe as shown and trimmed the screws flush.






Here's the door reassembled and mounted to the smokebox.






Today I attached the problem of making the curved sides of the saddle. "We don't need no stinking slip roll', I said. I had a piece of thick wall DOM tube with a 1.5" ID. I cut a piece to length (3.125") and bored the ID to 1.686", which is the diameter of the curveed portion of the front and back plates.






I cut this in two pieces lengthwise using the mill, did a trial fit, and scribed the ends showing where to mill.






After lots of "whittling" on the mill I ended up with this:






I made the bottom cover out of a piece of HRS a few days ago, so with everything assembled it makes a pretty hefty saddle. The sides are just clamped in place right now. After one more trial fit of the saddle and smokebox on the chassis, I'll weld the pieces together and paint.


----------



## kvom

Today's progress was to work on the linkage between the lubricator and the eccentric. I purchased the lubricator from AME, and being a dual pump unit is larger than the Kozo design. A visual check of it mounted under the running board shows no interference with the main rod. The attachment to the eccentric is a tiny bracket that will be screwed to the outer trunion of the right expansion link. I made it to Kozo's dimensions as show on p. 226:






Rather than the flat, bent bar drawn by Kozo, I'll plan to use round bar with one end threaded for length adjustment. The lubricator's lever arm has 3/32 holes, so I'll need to use a 2-56 screw for the attachment, rather than an e-clip.


----------



## ProdEng

A very interesting build to follow and even though my interest is in very small things I have still learned a lot from your machine setups. Thanks for sharing.

Jan


----------



## kvom

I ran into a problem today. I had mounted the lubricator that I purchased from AME on the underside of the right running board to the rear of the yoke, as shown by Kozo. This is a fairly large unit and nearly as wide as the running board itself. The today I mounted my rebuilt reverse shaft, I discovered that the reach rod is blocked by the lubricator. In addition, the right reverse arm would be quite close to the lubricator output ports.

So it looks as if the lubricator will be mounted under the running board forward of the yoke, and I will use the motion of the valve rod to activate the lubricator's lever. The piping runs to the steam chests will be easier in that location too.


----------



## kvom

Our club is holding our Spring meet, so I saw a good number of beautiful steamers on Thursday. I also got some good advice when I took the chassis and boiler assembly out as well. I finally decided that the throttle will operate via a bell crank from the side of the steam dome. In principle the crank will operate on the left side, but since the dome is detachable, it can be rotated 180 degrees if it looks like the right will be better.

In any case, I want the valve itself to be in the center of the dome. The hole for the steam supply is located forward of center, so I designed the following setup:






I made the steel plate on the CNC mill, and threaded the central hole 1/8-27 NPT. The five smaller holes will attach the plate to the top of the boiler via 8-32 screws. Here it's shown in position:






The steam passage is a slot milled underneath:






I need to drill and tap the five mounting holes, and also a series of holes to admit steam into the dome.

I got another good idea from Fred V, who brought his new Sweet William loco. His boiler wrapper was made from a length of stove pipe, eliminating the need to roll sheet metal.


----------



## kvom

Drilled and tapped the holes for securing the valve mount, and also drilled two steam supply holes into the boiler. Since the valve passage is 1/4" diameter, I figure two 1/4" holes can meet the demand.






With the dome cannister in place:






As it sits, there is 1/2" of space between the top of the cannister and the top of the valve. I could mill off about 3/4" off the valve and the same off the cannister to make the dome shorter if need be. For now I'll leave it alone.

I still have to design a suitable bell crank assembly and throttle lever. The way the reach rod for the throttle will be positioned means I need to make sure it won't interfere with the turret or water gauge. The valve stem turns 90 degrees from full closed to full open, so a shorter crank means less travel needed for the throttle. I want to ask some other loco owners in the club how far their throttle levers move.


----------



## kvom

Today's project was to make handles for the throttle and Johnson bar. This shows how you can make CNC lathe parts using a CNC mill as long as you can hold the stock with a collet and not have too much hanging.


----------



## kvom

I spent most of Saturday re-assembling the chassis for a second test run on air. I made gaskets for the cylinder-tee joints, cylinder heads, steam chests, and covers, but installed only on the cylinders thus far. Since the first run on air in November I remade a number of parts (yokes, reverse brackets, running boards), and painted. Aside from the chassis, I also worked on the smokebox and its attachments (see prior thread posts), and installed the ash pan

I had installed the brakes as well, but when I raised the frame on the bricks, the axle boxes bottom on the binders and jam the wheels against the shoes. So for this run I had to remove the brake mechanism.

With the Johnson bar mechanism working better, the engine seems to run more free. However, there's a "dead" spot between forward and reverse that sometimes prevents a smooth transition between forward and reverse. I've been told this is fairly common, and with a little bump of the Johnson bar the spot is bypassed.

Here's the video:

[ame]http://www.youtube.com/watch?v=aGRN_yjde6E[/ame]​It would be handy to have made a locomotive treadmill; this would have allowed test with both the brakes and springs installed.

I have a week left to fix a few more bits before heading for a family vacation trip. Then it will be time to plumb the boiler.


----------



## doubletop

Nice one kvom!!

I was thinking to myself you deserved a reply from at least one of us. Here you are posting pages and pages of good stuff and no acknowledgments from any of us lurkers. I'm sure the video will elicit a few more replies.

I'm no expert on this but to me the hissing sound when you are in neutral is the air escaping from the inlet to the exhaust without doing any work. In neutral all the ports should be shut the pressure holding down the valve block and no air escaping. So I conclude your valve timing needs a bit of work setting it up. That also may be why you've got that dead spot, the valve can't seat and the air is just escaping. I'd expect every newly assembled loco has this issue. 

Its a great job you are doing there

Pete

[EDIT] _its just occurred to me the reason I've experienced this problem is some of the gasket goo I was using ended up on the port face and the valve block couldn't seat properly so air escaped. Otherwise there is no way the pressure can jump the gap its either going to one end of the cylinder or the other but should never be able to go direct to the exhaust port._


----------



## vcutajar

KVOM

I have to agree with Pete. I am not into locos but have been following you with every post you submitted. It was fascinating seeing that video and it urged me to post something so that you know that I was following you also.

Vince


----------



## stevehuckss396

I'm still with you too buddy!! I'll be here until the final bolt!!


----------



## ProdEng

I would add my voice to those interested in your progress despite not wishing to make a loco. After reading a few of your more recent posts I went back to the beginning a read the lot. You have shared a fascinating engineering journey for which I thank you. 

Jan


----------



## kvom

The steam chests are not sealed as yet, and I can feel a lot of air escaping under the covers. That said, there is some air coming out the exhaust as well, so I'll check the valve positions after stopping it in neutral. Thanks for the hints.


----------



## kvom

After 3 weeks vacation trip and a week of jet-lag afterwards, I was ready for a bit of shop time. I'm still pondering the throttle issue and got some new ideas from the Chaski forum. To see more clearly where the throttle bar would be, I decided to go ahead and finish the cab front and sides. The front is a larger piece of sheet metal than can be mounted in a vise, so it will need a fixture plate to CNC. However, the sides already have a fixture plate from when they were machined on the Bridgeport. What was needed are the holes for a decorative rivet pattern plus the holes for mounting the sides to brackets that attach the sides to the running boards and the front to the sides.

I drilled three mounting holes in each of the sides using the Bridgeport, and then matching holes in the Corian fixture plate using the CNC mill. After attaching both sides together using 6-32 screws and then to the plate, it was fairly quick to spot drill and through drill the 60+ rivet holes in both sides simultaneously.






Definitely faster than manual drilling.

I'll be using #7 drive screws for the fake rivets. For the front, which is over 13" wide, I'll attach a corian plate directly to the table.


----------



## stevehuckss396

NICE! Still here enjoying every minute of it!!


----------



## kvom

Yesterday I took an entire afternoon and into the evening just trying to cut the cab front out of some 16ga sheet. After cutting out a Corian fixture platre I determined that I didn't have any screws that would work with the tilt tables t-slots. So I decided to try to clamp the metal, Corian, and table together in a way sufficiently rigid so as not to slip when milling. This lead to some ad-hoc clamps shown in the photo below.

The next problem was that without the vise my spindle descends only to within 3" of the top of the table. Not an issue for drilling, but I then needed to use longer endmills than I would have liked. So the window cutouts were made with a 5/8" 4-flute endmill for a roughing pass, and then with a 3/8"x3" endmill which is pretty flimsy when stuck out that far. Had to take only .02" DOC and it still buzzed in the corners.

The outer profile needed to be milled in 3 separate sections with the 5/8 EM as I couldn't clamp securely enough and clear the EM all the way around. So after each section I needed to move the clamps around before running the next. The metal still lifted off the Corian in places resulting in a lot of burrs that needed cleaning up this afternoon.

Anyway, here's the part on the mill at the end:






After a good long while deburring, I mounted the front and sides to the engine chassis using magnets for a poser shot:






Next step will be to put on the boiler again and see how it fits relative to the cab.

Since the vise was off the table on the CNC mill, I decided to take it apart and clean out a couple of years gunk and swarf. The coolant I'm using tends to clump the chips together. Slides a lot smoother after the cleanout.


----------



## ozzie46

Coming along nicely Kirk. You've done a wonderful job on her so far. 

 Ron


----------



## kvom

After more cogitation and some online discussions, followed by some measurement and CAD verification, I have again re-designed the throttle mechanism. By remaking the interface plate between the ball valve and the boiler, I now have the valve to the right of the centerline. This allows me to make a bell crank to attach to the valve that will lie on the boiler centerline. With the crank pointing downward, the activating reach rod will be close to the top of the boiler and on the centerline. Thus, other than substituting the ball valve for Kozo's needle valve, the rest will be quite similar.

Here's the new place and valve alongside the previous one that placed the valve on the centerline:






A criticism of the ball valve is that it might not be progressive (i.e., jerky starts). If that turns out to be the case, then it would be possible to replace it with a slide valve or even a v-hole valve if one could be found in this size. In either case the reach rod and the rest of the throttle mechanism would not need to be changed.


----------



## kvom

Still hitting some roadblocks on the throttle/dome setup, so I turned my attention elsewhere.

I've wanted to build a treadmill for the loco, since raising it off its rails to run and supporting it with bricks has been less than ideal.  The components are a set of skateboard wheels plus some stock I had on hand.  The 4 axles were turned from aluminum, necked down to 1/2" to pass the frames, ajnd 1/4" to fit the wheel bearing holes.  The wheels are retained by e-clips.  Frame is some 1/2x3" HRS.  Seems to work very well during a short tryout run.

Here's the loco chassis on the treadmill.  If/when I take it apart again I'll replace the clamps with a length of all-thread and some nuts.






Although not on the critical path to get into steam, I bought a Locoparts 12" steam whistle kit from a fellow club member over the weekend, and I decided to do the rough turning on the aluminum chamber casting.  The object here was just to get it round from end to end.  There was quite a bit of extra material, so no critical decisions at this point.  With center drill holes on both ends, I turned the small end down to 5/8" at the tailstock, then secured that with a 5C collet and turned the entire length down to 1.45" diameter.  All interupted cuts with a small DOC.

Eventually most of the length will need to be turned to a light press fit into a brass tube with an ID of 1-7/16".  Before then, the small steam admission end needs a lot more work, including 2 different threads.


----------



## rhitee93

I like the treadmill, that is cool


----------



## kvom

Today was just dedicated to trying some things for fit.  Used the engine hoist to put the loco and boiler together on the floor, and positioned the tender behind:






Because the plans for the 1.5 scale boiler place the steam dome further forward proportionally than for the 3/4" scale, the throttle tube into the can will be longer.  I measure 5" from the rear of the dome to the front of the cab.  Sitting on the rear of the tender, I would have quite a stretch to reach a throttle that was just inside the cab, so the tube will likely be extended in the cab at least 2-3" and will need to be designed not to interfere with whatever the turret turns out to be.

Here's a shot taken at eye level with me sitting on the tender:






It seems that the manual foot-operated brake lever will work well with my shoe resting on the tender footrest.  OTOH, getting a good view through the firedoor will require scrunching over.  Adding a seat or cushion will make me sit even a bit higher.  Stoking looks as if it will be fine.  The front of the tender and the loco's rear footplate are pretty much on the same level.  Kozo doesn't use an apron on the small loco, so I'll need to make something.

The tender's provision for a drawbar is about 1/4" lower than the loco's.


----------



## don-tucker

Looking good
Don


----------



## rhitee93

I just realized how big that engine is 

Very impressive!


----------



## kvom

Spent the last shop sessions making the drawbar and drawbar pin.  To adjust the fit I used the auto lift to position the tender frame level with the loco so that the front tender truck was on my booty-fab track:






The attachment for the tender drawbar is not readily accessible with the tank in place, so I had to remove it termporarily.

There's about 1" of space between the tender's bumper and the loco's rear footplate.  Any closer would interfere with the foot brake.


----------



## kvom

I will need to mount my AME lubricator on the front of the footboard rather than behind the yoke, as Kozo shows.  That's because it's wider than Kozo's and thus would interfere with the reverse reach rod.  So now the activating motion will be the valve rather than the eccentric strap.

The value travel at full gear is .6".  OTOH the lubricator lever needs to move only about 10 degrees to advance one notch, meaning that the lowest hole on the pivot arm will move about .32".  To account for this, I've made a "lost motion" strap to fit to the lever arm:






The 5-40 screw in the rounded end adjusts the travel in the slot.  The other end will have a 1/8" diameter rod approximately 2" long connecting to the fork at the end of the valve rod.  Since the lever will be a bit outboard of the valve, the connection will need to be offset from the valve approx. 1/2".  I have some ideas on how to do that once I mount the lubricator to the footboard.

The holes in the lubricator's arm would be best fit by a 3-48 screw, which I don't have.  For the time being I'm using a long 2-56 to fit.


----------



## kvom

Today's project was to finish the lubricator linkage.  The photo is pretty self-explanatory:






Rolling along the track with the adjusting screw all the way in appears to advance the ratchet two teeth, which is what I expected with full-forward gear.

I still need to bore a hole in the footboard for the filler cap, plus get a shorter/different screw for the lever attachment.


----------



## rkepler

kvom said:


> Today's project was to finish the lubricator linkage.  The photo is pretty self-explanatory:



Did you add that view port to the lubricator?  Looks handy, I might add one to mine.  I get more than enough oil for my 1.5" scale Shay with the AMES lubricator.


----------



## kvom

The view port was added by AMES and is now standard (with an increased price).


----------



## johnnyo

Very nice Kvom, I hope to get back to my own soon. I have a couple other projects distracting me yet. I did finish my duplex steam pump and main rod with adjustable brass's. I'm playing around too much with this DraftSight program I downloaded, it's pretty nice, I'm used to auto cad lt so its a good fit. Good luck with you're build, I'll be following you along.
Johnny O


----------



## kvom

Got back to work on the loco after a break.  "Final" throttle design will have a tube connecting the steam dome with the turret, with the tube being under steam pressure.  I ordered a 1 foot piece of brass tube from McMaster; it's 1/2" Nominal but actual OD is .840" and ID is .622.  This will give clearance to a two-piece reach rod activating the globe valve.

Today I made two flanges that will be silver-soldered to the tube.  I spiral milled the center hole, the first time I'd used that technique on the CNC mill.


----------



## SilverSanJuan

WOW!  I just spent the last three days reading this entire thread.  Amazing stuff kvom.  Really beautiful work.  I need to get a copy of Kozo's book.  My first HO scale locomotive was the little B&O 0-4-0 switcher.  Looks just like this with the slope back tender.  I got that when I was about 8 years old.  It would be really cool to come full circle and make this engine.  Of course I have lot's to learn before I start on such a project.  I know I've picked up a lot of things just reading this thread the last three days.  Thanks for sharing with us.  And, keep pushing for that first steam up.  Seems like your pretty close.

Regards,
Todd


----------



## rhitee93

Oh, having a CNC to cut big holes is very addictive.  I'm afraid you may be ruined forever.

By the way, I am still impressed by the scale of this project!


----------



## kvom

Further work on the throttle mechanism:  since I'm trying to design as I go, I sometimes feel like flying a bit blind.  So I bashed together the following activation mechanism that would be attached to the turret when built.






I drew it up in CAD trying to assure that I would get sufficient travel from the reach rod.  It looked good on paper, so spent a half day machining the various pieces to verify.  The globe valve that meters the steam has a 90 degree spindle travel from full-closed to full open.  With a 1" crank bar, that means a 1.4" lateral travel of the reach rod.  To minimize the vertical displacement of the end of the crank, its closed position is 45 degrees from vertical.

Given that the throttle bar would be pulled backwards to admit steam, the closed position is as shown in the photo.  I machined the top portion of the bar at a 10-degree angle from the bottom, as that was the most I could get from the piece of brass I started with.  However, I may remake it with a greater bend if needed once I have the turret made.

After some advice from other builders, I will make the 2-piece reach rod from stainless steel rather than brass.  I also need a different connector for the end since the "fork" reduces the travel distance.


----------



## kvom

After some more discussion on the steam dome with an experienced builder, I started on fabricating the "can" components that will be welded to the boiler.  The first issue was that the flange I had originally was too thin.  The tapped holds that secure the cover should not be through into the steam.  Therefore I turned the flange off the can leaving a simple cylinder 3.375" OD with a 1/4" wall.  Now I need a ring that will be welded to the can to form a 1/2" thick flange 1/2" wide, meaning that the OD will be 2.375".

I started with a piece of 5/8" thick HRS about 4" square, faced both faces with a facemill on the manual mill, and milled two of the sides square.  Now I could mount the stock on the CNC mill to remove the center material.  For this, I wanted to try something new to me.  My CAM program allows me to easily draw a flat spiral with any given distance between the loops.  So using a 5/16 endmill and a .03" spacing (9% engagement), I would be able to mill at full depth using just the side flutes.  This is a type of "high speed machining'.  To start, I used a 3/8" endmill to spiral drill a .6" diameter center hole, and then the spiral.  A finish circular path brought the hole to its desired diameter.






Total machine cycle time was about 15 minutes.

For the OD, I could have programmed a profile cut in CNC, but a large endmill would have cut into the vise soft jaws, and a smaller endmill would have meant a slot depth greater than the tool diameter.  So I decided to use the lathe.  First I needed to round the corners as much as possible with the manual mill.  Here's the setup for the first pass:






After trimming 4 corners I mounted the work on the lathe as shown here.  I used a pair of 1/8" parallels to space it away from the jaws to avoid cutting them.






Then I turned it to slightly larger than final dimension, faced both sides, and chamfered one outer edge to allow a space for welding filler.






The cover mounting holes will be drilled and tapped after welding an cleanup.


----------



## kvom

The next part for the throttle is a flange that will be welded to the steam dome "can" and mate with the brass tube/flange.  This piece is made with 316 stainless.  I started with a 1-7/8 diameter by 1" long round bar, face both ends on the lathe, and through drilled a 5/8" hole.

Then I milled a pocket in the CNC mill soft jaws to hold the bar, and milled the profile and enlarged the center hole to .90".  Finally drilled two holes to be tapped 10-32.  Here's the result this far.


----------



## kvom

After tapping the two mounting holes, I attached the flange to a piece of aluminum with screws and set up as shown below.  Then the back of was milled to match the diameter of the steam dome can.






Here's the piece shown in its approximate position.






I also made a short tube from 316 that will be welded both to the flange and to the inside of the can, making it steam tight.


----------



## kvom

Seems I need to start over on the steam dome canister, so I will make it one piece rather than needed to weld on the flange.  I drove down to Metal Supermarkets today and browsed their drops area.  I found this chuck of HRS, 4"x4"x3.5" (56 cubic inches).  It will be machined into a cylinder with OD 3.375" and ID 2.375" (15.8 cubic inches).  So that block is 72% swarf to come.  

I could program almost all of the work on the CNC mill, but I don't have endmills that are long enough.  So I will likely rough mill the block to a cylinder and then do most of the rest on the lathe.  I'm still thinking about the best steps.


----------



## SilverSanJuan

Wow!  That's a chunk of steel alright!

I just received the material for my tender wheels and axels yesterday.  Cutting them to size today.  But, mines only the 3/4" version.  So, smaller pieces. 

I look forward to your updates.

Todd


----------



## kvom

Decent progress on my "hunk-o-steel".  First op was to face mill 1/2" off one of the long sides to get a 3.5x3.5x4 oblong.  Next center drilled both ends for later lathe work.  Now milled off the corners lengthwise to get an octagonal cross section.  Next drilled and tapped a 1/4-20 hole 1/2" deep in one end, screwed in a SHCS, and cut off its head.  Now I had this:






On to the lathe between centers, using the screw shank as a dog driver.  Then lots of small interrupted cuts until round, and a final cut to 3.375" diameter:






Back to the CNC mill to cut a pocket in soft jaws to hold the cylinder"











Next session I will use this setup to drill a through hole in the center using a succession of drill from 1/8-1" by eighths.  Since the work is 4" long, I plan to run a drill half way, then reverse the work in the vise and repeat the op.  Then it will be back to the lathe to bore out to the final dimension.

Alternatively I may use the boring head.


----------



## kvom

The through drilling went fine as foreseen through 5/8" diameter.  When I tried 3/4" drill there was not enough torque and the drill stalled the motor (prescribed RPM was 400).  I decided to see if I could mill out the bore rather than hand a heavy piece on the lathe with no end support.

Some years ago I bought a lot of endmills online, and there were several > 1/2" in diameter.  I found one 5/8" 4-flute mill with 2" flutes, so decided to try that.  Using the G-wizard feed&speed calculator, I decided on a .25" radial engagement and a .04" ramped depth of cut, which allowed 1020 RPM and 15 ipm feed.  This worked out to be pretty easy on the tool (no chatter), and about 40 minutes to mill 2" deep from both sides.






Here's progress to-date:






The bore is large enough to clear the valve body and the walls are a bit thicker then .5".  Any further enlargement can be done on the lathe.

I also went over to visit a friend who offered to silver solder my copper tube/brass flange since he had a turbo torch.  Alas, both propane and Mapp gas failed to generate enough heat.  I'm going to try it again with the oxy-acetylene torch later.


----------



## kvom

Here's the (slow) progress on the steam dome/throttle.  Made the lid, tapped the holes, and bored the hole for the throttle rod.






Mock-up assembly:






Tried to SS the brass flange again today using black flux and my little oxy-a torch, and still couldn't get it hot enough.  Arggh!  Will try again with the large torch at the club later on.


----------



## rlo1

Is the supplier of the 1.5 wheel cutter still selling them? Thanks - Ron


----------



## kvom

rlo1 said:


> Is the supplier of the 1.5 wheel cutter still selling them? Thanks - Ron



He made a second batch recently, but I don't know if all were spoken for.  Email him at jtdute "at" yahoo "dot" com


----------



## rlo1

Thanks, message sent


----------



## rlo1

Got a quick reply from Jeff.  He is out of stock on the cutters but is considering another run.


----------



## kvom

Made a little progress the past few days despite lots of other distractions.

First little job was attaching the number plate to the smokebox door.  Soldered a little piece of round brass rod to the rear, drilled and tapped 10-32 to match the door, and attached with a set screw and a ja, nut.






Second task was a complete remake of the reversing bar assembly.  The 3/4" scale setup for the latch did not scale well, so I came up with this design for the lever and locking bar.






I'll wait to locate the notches on the quadrant before repainting it.

Final job of the day was making two nuts for locking the crank to the spindle of the throttle valve.  The spindle is threaded M6x.05, , not an easy size to find locally where all M6 fasteners at 1mm pitch.  It seems to be a good idea to try to use stainless for stuff in the steam dome, so I decided to make two nuts for SS316.  I found and ordered a 5.5mm drill and a tap online.  Since I had some 1/4" 316 bar, I drilled and machined the nuts on the CNC mill.  The nuts will take a 3/8" wrench rather than 10mm.






After freeing and facing to size manually, they do fit the valve.






The fit is pretty loose, whether due to the drill bit or the tap (both imports).  They should still work well enough though.  I also tremade the crank in 316.


----------



## kvom

Some more halting progress.  Made the first part of the 2-piece throttle reach rod from 1/4" 303 stainless, then a brass pin to connect it to the valve spindle crank.  The assembly is retained by a small stainless latch pin as show in the pic.  The through hole in the brass was drilled with a #56 drill, the smallest hole I can ever remember drilling.  







While not visible in the photo, each end of the rod was milled flat half way through the diameter to provide a better mating surface.

The second part of the rod will be identical to the first, except its length will be determined by the size and position of the turret when made.


----------



## kvom

Thanks to a friend from our club, my steam dome is now welded up on the boiler.






I need to grind the welds and paint.  With the flange mount for the throttle tube, I'll have some trouble with a dome cover, but I do have a few ideas that way.

I also bought material to make a rolling stand for the loco and tender, mainly 1" square thick wall tube.  Started by welding up the pads for the casters.  Not pretty welds, but they should hold together.


----------



## kvom

Got the throttle pipe and flange silver soldered together this week using the large oxy-a torch at the club.  Now I need to determine the length of the tube and solder another flange on the other end to connect to the turret.

In the meantime, I did a bit more on the rolling stand, welding the lengthwise parts of the base and bolting on the 4" casters:






The long span won't support a huge amount of weight without bending, so there will need to be some "trussing" to make everything solid, even though the loco and tender together will weigh less than 300 lbs.  Cleaned out the truck bed this afternoon, so I can mount the carry board and measure the height of the rails on the truck.  Then will  shoot for the same height with the stand.


----------



## kvom

More work on the rolling stand, which is now a monorail.  My material calculations were off by one stick of 1" tube.  Should get another later this week.  Found out that I was not cut out to be a welder.






My order from Locoparts came in this week, including the water glass, so I'll need to locate/drill/tap the backhead, always a nerve-wracking task.


----------



## kvom

Finished up welding the stand, and moved the loco and tender chassis onto it:






Now a better measurement of the total connected length shows that they will just fit on my truck carry board without hitting the truck toolbox.  Even with the tender on the stand, the 8' rail length allows over a full turn of the drivers.

I also drilled the hole for the water gauge in the boiler backhead.  Wanting to make a straight hole, I came up with the idea of super-gluing a drill bushing onto the backhead.  Good idea in theory, but the bond was not strong enough to hold once I started drilling.  However, by keeping the bushing on the drill and against the backhead using magnets, the hole looks to be pretty damn perpendicular.  Now if only I can find my 1/8 NPT tap.

I located the hold by measuring the top of the crownsheet through the top  bushing, and then drew a line across using a sharpie.  Then a second line at the level that made the bottom of the glass 1/2" above the first line.  Finally over the left so that the fire door won't hit the gauge.


----------



## stevehuckss396

Does the width of the stand make you nervous? Seems a little narrow. I would be scared it would tip over while moving it around.

Everything looks great!


----------



## kvom

The casters are 2' apart, and it's very stable (and pretty heavy).  With the two chassis mounted, the whole thing is 300+ pounds.  The design is such that there are no sheer forces on any welds.  I measured the rails with a digital level and they are within 1 degree of level.  I intentionally made the center supports 1/8" shorter then the ends and clamped down to weld them.  So any tendency to roll will be towards the center.


----------



## kvom

Got the backhead tapped for the water gauge and mounted it for a look see.  Also cut gaskets for the throttle tube and the top for the dome, and did a trial fit.






I originally planned the two bushing on the top for the turret and the water gauge, but now that the throttle pipe will be attached to the turret and under steam pressure, I have one for a different purpose.  Might make sense to use one for the pressure gauge rather then attaching it to the turret.

I made this adapter from some 9/16 hex brass bar.  1/8-NPT male on one end and counterbored 5/16 on the other.  This will be used to connect 5/16 tube to the elbow for the water glass.  Took less than 15 minutes to make on the lathe.  Seems I can save a few $ making this type of fitting vs. buying at the hardware store.






I don't have any suitable material for making the turret as yet.  Looking for some brass 1.5" square bar about 4" long.

I ordered some 5/16 straight copper tube that will be used for the blower line inside the hollow boiler stay, and a coil of 5/16 tube for the rest of the piping from Mcmaster.  Seems to me I could start by doing the water feed from planned quick disconnects (to be purchased) to the injectors and thence to the boiler check valves.  The rest will need to wait until I can make the turret.


----------



## kvom

Having sourced a pair of Parker quick-disconnect couplings for the tender water supply hoses, I set out today to make the brackets that attach these to the frame.  Kozo specified two different lengths (p. 193, drawing 33-11), but seeing no real reason for this I made both the same  as the right side dimensions.

The first step was using the CNC mill to drill the holes and mill the profiles.  Stock is CRS 1.25x1x2.5".






The two sides are mirror images as the rear of the brackets are to be tapped 1/8NPT, and the front soldered to 5/16 tube.

Next to the BP to tap one side.  I really like the spring-loaded tapping follower; ensures the tap goes in straight.






Then I cut the two pieces apart on the bandsaw and then milled off the remaining bottom stock, and drilled the mounting hole for the 1/4' screw.






The brackets are mounted using the rear screw that also fastens the grill support rails.  On the left side, there's nothing to get in the way:






On the right side the ash pan latch will be directly below the coupling with the brake pedal directly above, but it looks as if it should be OK.

My tender outlets are threaded 1/4NPT, so I'll need two different sets of hose barbs.  I'll probably use 1/4" ID hose.


----------



## kvom

Being warned that my steel brackets are liable to rust and foul the injectors, I came up with a plan to save the day.  I drilled/reamed the brackets to .368 (T size), then turned/drilled/tapped these sleeves from some brass rod.  The sleeves will be soldered to the copper tube as well as the brackets.


----------



## kvom

First part of 2013.

There was a nice NYE getogether at the club, where I picked a few members' brains on soldering the piping.  Seems the black flux needs too high a temperature for soldering copper/brass tube using the silver-bearing solder;  I need zinc chloride.  I looked it up on the net, and hunted for a local source.  Seems I might want "Rubyfluid liquid", that should be available at a hardware store not too far away.  We'll see tomorrow.  I'll also need some 1/8" copper tube for the siphon and piping the lubricator.  I'll have a lookout for that too.

In the meantime, since everything is closed on Jan 1, and it was raining all day, it was a good day for shop time.  I made this coupling for the pressure gauge and siphon.  I bought the gauge online from a fellow steamer, so hopefully it will work properly.  It's threaded 1/4NPT, so my coupling is tapped to match and drilled though 1/8" for the siphon tube.


----------



## Brian Rupnow

Kvom---Happy New Years!!! I can't even imagine the magnitude of the project you have underway there. You have been a faithfull poster over the past year, and shown some very high quality work and some good machining tips. Thank you for taking the time to do all this and post it on the forum---Brian Rupnow


----------



## doubletop

kvom said:


> First part of 2013.
> 
> There was a nice NYE getogether at the club, where I picked a few members' brains on soldering the piping.  Seems the black flux needs too high a temperature for soldering copper/brass tube using the silver-bearing solder;



Kvom

This is what you need; its also good for stainless so a one stop shop for a silver solder flux. Apparently similar to the JM Tenacity #5 






http://www.harrisproductsgroup.com/en/Products/Alloys/Brazing/Fluxes/Stay-Silv-Black-Flux.aspx

Pete


----------



## kvom

Got in some fittings from McMaster, so made a start on the tender water piping.  Screwed in these elbows (1/4NPT to 5/16 compression, and after placing the tank onto the frame discovered that the end of the compression fitting is about an inch too high, so that the front of the tender frame blocks it.  So I'll need a coupling of some sort to lower it.  A simple straight barb wouldn't work as the supply tube would hit the wheels.  Same problem with turning the elbows to face inwards.






I also found a 6' coil of 1/8 copper tube with some fittings for sale at Autozone (brand name Sunpro).  The fittings allow 1/8NPT male or female, so I plan to use these for the siphon rather than soldering.  My tubing cutter is too large to cut this, and a coping saw doesn't work much better.  Found I coud cut it cleaner with scissors.

I also wanted to replace the brake assembly on the chassis, only to find that the rails get in the way.  The only way to install them is from the bottom with the drivers in the air.

Ordered a chunk of brass to make the turret, so if I can get that build I can get serious on the piping.


----------



## kvom

After a couple of weeks away from home, I spent an afternoon in the shop with the A3.  Propped the loco frame on some riser blocks to get the wheels off the rails, and was able to mount the brake assembly.  Everything is a tight fit, so not too easy.  Anyone who builds the brakes and is ready for a final assembly will be advised to install them before any valve gear or rods.

Next I re-installed three of the spring packs.  The springs are quite strong, so I found the best way to do the rear pair was to install them on the hangers with one hanger unattached to the frame.  Then I could press down enough to start the screws for the other hanger and let the screws compress the springs.  I also found that installing the back hangers for the front drivers was a real PITA.  The drivers keep you from inserting the lower pins from the outside, so I had to finagle installing the tiny e-clips using needle nose pliers and strong language.  These hangers should be mad and installed early in the assembly process, before the drivers and axles.  Got one spring pack on and found that one of the retainer clips for the other is missing.  So that's a little fab job for tomorrow.  With the springs installed I'll be able to put on the boiler and smokebox to start laying out the piping.


----------



## kvom

I got the springs mounted and then put on the boiler and smoke box.  With that weight the axle boxes are close to the center of the their travel range, which seems likely is the design point.  Here's a pic afterwards:






The fact that the boiler drawing put the steam dome 2" too far forward is going to make the loco look mis-proportioned, even with the sand dome moved forward as shown.  The bell will end up very close to the smoke box.  The throttle tube is higher and thicker than Kozo's drawing, so I'll need to modify the front wall of the cab to fit eventually.

In any case the club boiler hydro-tests are next month; since I've now drilled all the holes into the boiler that are needed I'll be ready for steam-up afterwards if I can get the piping done.


----------



## stevehuckss396

she is really looking good.


----------



## kvom

I made a start on the turret today.  The body of the turret is a piece of 360 brass, 3/4x1.25x4".  Drilled the two holes for mounting to the throttle tube and drilled/reamed the 1/2" center hole for the throttle rod gland.  My design for the gland derives from that used for the valve rods, using a Viton o-ring for sealing the 1/4" SS throttle rod.  The gland itself is two-piece, the larger brass piece fitting into the turret hole and the smaller bronze piece fitting the larger.  The two pieces leave a pocket for the o-ring.  This design will allow me to remove/install the 2-piece throttle rod and the valve crank without removing the turret itself.






With the parts assembled, the back view:






This view of the front shows how the cross-drilled hole will intersect the main steam passage to supply the injectors while missing the mounting holes.  Any other valve holes will intersect the cross passage.


----------



## kvom

Today I drilled the cross passage in the turrent without a problem, using a C drill bit from each end (C is the tap drill for 1/16 NPT).  Then I assembled the turret block and rear flange on the loco for a test fit (the rear flange needs to be marked on the throttle tube before soldering so that the turret is horizontal).






Then I discovered a problem:  The right end of the turret is even with the reversing lever when at full forward, and there's not enough room for the injector valve and a pipe union.  I'll have to decide what to do about that.


----------



## kvom

Did a few minor tasks in the shop today.  I had to take the boiler and smokebox off the chassis as I need to remove the rear footplate.  It will need to be counterbored for the drawbar pin as the head of the pin interferes with the fire door.  I attached the brake pedal and reach rod in order to get an idea of how I'd mount the injector at the rear of the frame.  There's a lot of "stuff" in that area: blowdown valve, ashpan latch, and the foot pedal.  Looks like it will just fit without being too far forward.  I don't want it too close to the rear driver as that would mean a sharp curve in the water supply pipe.

I did a test fit on the left side, where there is nothing to interfere but the blowdown valve.  With the valve clamped to the frame in its approximate position, I ended up with this:






I drilled a second hole in the bracket to move it higher, as shown.  The bottom of the injector is still only about an inch above the rails.  I'll probably try a bit of an s-curve on the copper tube to position the injector a bit higher.


----------



## kvom

After some advice from a number of other builders, I believe I have located the "best" spot for the injectors; the water inlet will be about level with the top of the frame, and as far back as I can get it.   I have some ideas about routing the water input but will have to experiment a bit before finalizing the plan.

In the meantime I built a pair of parts that will connect the Locoparts blowdown valves to the boiler.  On the .75" scale model, the single valve is screwed into the boiler directly with no frame in the way.  On the 1.5 scale version, he specifies a single valve going through the left frame only.  I will have a blowdown on both sides, and rather than build them I purchased a pair from Locoparts.  The male pipe thread on these is too short to pass through the frame  and screw into the boiler, so an extension is needed.  Originally I was thinking that a short nipple and a bushing would be the easy way to go, but today I decided to just make each as a single brass part.  Here's the result:







These will position the valve outboard of the frame about 3/4 of an inch so that the lever will now be under the walk board.  This will allow me to attach a lifter that passes through the board and that can be activated when the locomotive is moving.  It should also be possible to route the water feed line to the injectors behind the valve rather than in front.

I also countersunk the hole in the rear footboard so that the draw bar pin is recessed and no longer interferes with the fire door.


----------



## rkepler

kvom said:


> I drilled a second hole in the bracket to move it higher, as shown.  The bottom of the injector is still only about an inch above the rails.  I'll probably try a bit of an s-curve on the copper tube to position the injector a bit higher.



The Superscale Economy injector will lift fairly well - on my Shay it's fairly high and has no trouble injecting even when the tender is about dry.  I had to look around to get an image of the off side but here it is in the final position:






(One of these days I'm going to direct the overflow away from the frame...)


----------



## stevehuckss396

You have a shay?  Have you ever posted pic of it here? I would love to check it out.


----------



## kvom

Is that valve on the water line what you use to start/stop, vs. a valve on the tender?


----------



## rkepler

kvom said:


> Is that valve on the water line what you use to start/stop, vs. a valve on the tender?



It's used to 'throttle' the injector so yes, I put it there instead of the tender.  Works OK either place.  One thing I was told that would not work was to plumb the axle pump bypass through the injector input (i.e. the return to tender line).  It works fine but you can see the axle pump's impulses affecting the feed when the tender is very low - the overflow cycles a little bit.

I don't really want to hijack this thread but here's a shot from last year:


----------



## vcutajar

KVOM
Still following your interesting build of the loco.  I do not think I will be building a loco in the near future (nowhere to run it locally) but it is still fascinating seeing it slowly come together.

Keep it up.

Vince


----------



## kvom

Built a mockup of my throttle design to check the geometry.  It looked good when I drew it in Draftsight, but I needed to make sure the movement was at least fairly smooth.  Seems to be good, and I get the 2" travel needed to open the valve full closed to full open with a 1" crank.


----------



## kvom

I got quite a bit done over the weekend, esp. since the Jeep is awaiting parts elsewhere and there is room in the shop.  Since the club's hydro test day is coming up next month, I decided to plug as many holes as possible in the boiler.  So in addition to actual plugs, I also screwed in the blowdown valves and boiler checks.  I discovered that for a boiler check I needed to either do it before putting the boiler on the chassis, or else remove the walkboard.  I ended up putting one of the boiler checks into the glass gauge hole.  In any case, the 4 valves will get tested for leakage.

I also drilled and tapped a 1/4 NPT hole in the steam dome cover.  This will be the water fill point.

After installing the throttle valve in the steam dome, I proceeded to try to finish the throttle reach rod.  This is a 2-piece rod with a brass joint, similar to how the inner piece attaches to the throttle crank.  After making the connector pin from brass, I decided to use brass cotter pins rather than the steel latch pins to retain them.  Seems the latch pins would rust.  The outer piece was left long and the turret attached.

Here's the throttle valve installed:






And the unfinished rod installed.






Now I was able to mark the rod for length, remove it, cut, and thread the end 1/4-20.  The rod material is 304 SS.  Now after reassembly I could test the action of the throttle.  It seems pretty smooth.  I need to remake the "fork" that screws onto the rod.  Here's the finished rod:






And the throttle assembled:






The next task was to work on the transport board for toting the loco and tender in my truck.  It's a 4x8 sheet of outdoor plywood that had 3 coats of outdoor paint.  Hopefully it will hold up since I will probably leave it outside in the truck bed most of the time.  In any case, I put it on the auto lift and raised it until I could roll the A3 onto the board.  With it and the tender positioned so that the tender's coupler is just inside the end of the rail, I positioned a retainer I made from an old steel angle block.






The retainer is bolted to the board with a couple of 1/2" screws, and attaches to the loco's coupler pocket.

With the rolling stand freed up, I took the opportunity to paint it.

I still need to make a pair of hold downs on the board for the loco and tender.  I';; use a ratchet strap for the tender, but need to think a bit for the loco.

If the weather hold up I plan to take it to the club this week for a tow around the yard and to test the foot brake.


----------



## kvom

Today I added tender tiedowns to the carry board.  These are 2" ubolts on each side secured by bolts on either side plus a metal strap underneath.  With the loco and tender on the board, here's the travel setup:






The big ratchet strap is not cinched at all as it could easily bend the sides of the tender.  The loco is restrained by the coupler pocket at the front and the drawbar at the rear, so for now I think it's OK for travel.  I'll consult with other club members on this.

With the board on the ground, I was able to sit on the tender and check out the ergonomics.  The foot brake pedal is easy to reach, as are the reverse and throttle levers.   As well, the intended position for the injector valves are easy enough to reach.  The pressure gauge will likely end up behind the turret with the face angled up.  I'm don't think it will be very easy to see the fire that well without leaning way down, so I'll have to wait.

Here's the view from the cab:






As can be seen, the throttle links will interfere with the water glass.  I think the best solution may be to have a 1" nipple and bushing in the backhead and thus move the glass backwards to clear.    The valve for the blower looks like it will fit fine just above the through stay.


----------



## kvom

After posting the previous message, I decided I could make an extension off the backhead myself similar to the extension for the blowdown valves.  A short time later:


----------



## kvom

Started planning the inject valve piping.  I used Draftsight to draw the tube, elbow, valve, and union on each side of the turret. I then printed at actual size and laid onto the turret to see how things look.  I made some adjustments and ended up with this:


----------



## kvom

Started on the turret piping for the injector valves today.  I discovered that the cross passage in the turret is too close to the edge to allow enough threads for a 1/16NPT connection.  So I drilled and tapped some 3/8" brass round bar, then milled 3/8 holes in the turret.  The bars will be soldered into the turret, and the elbows screwed into them.

Here's where I left off this afternoon.  Next shop session I'll solder the connections.  The straight sections are 5/16" OD thick wall brass pipe I got at Cabin Fever last year, along with the PMR bronze elbows.  The pipe is hard to thread as the die gives very stringy chips.  I have some 5/16 hard copper tube that can be threaded and might have worked better.  I'll try that on the next connections, which will be between the valves and the unions.


----------



## stevehuckss396

Still following along! Everything looks great. It's starting to look like a little loco.


----------



## kvom

Started piping work on the left-side injector.  The steam inlet pipe from the turret holds it in place for fitting the water pipes.






The water inlet pipe shown is just a "trial" using hand-bent copper tube.  I need to borrow a tube bender as the tube shown won't work properly.  After taking the pic I took the turret and this part down to seal up the boiler for hydro this Saturday.


----------



## kvom

We had annual boiler hydro testing at the club today, and I'm happy to say my boiler passed.  The only leak was a pinhole in the TIG weld at the side of the steam dome, and some peening with a punch closed it up.  Tested at 200 psi.  The only downer was that neither of the Locoparts boiler check valves worked.  They were completely open when filling the boiler (no pressure).  So I took them off and inserted plugs.  The gaskets I made for the steam dome and throttle sealed perfectly.  I made them from paper gasket material purchased at Ace Hardware, and used a mixture of steam oil and powdered graphite as the sealant.

I'll open up the check valves tomorrow to try to see why they're completely open to water flow.


----------



## stevehuckss396

That's good news. That has to take some of the pressure off. Hahahahaha!!!


----------



## Lakc

kvom said:


> The only leak was a pinhole in the TIG weld at the side of the steam dome, and some peening with a punch closed it up.


Was it leaking from a depression in the weld puddle where the weld ended, or was it an overlap/penetration issue somewhere along the weld?
Glad to hear you got past that major step.


----------



## kvom

At 200 psi there were a few drops coming out in the middle of the weld material,  This is the TIG weld where the SS throttle tube connection is welded to the cannister.  Since there are many experienced builders at the club who approved the "fix", I'm not worried about it.  Peening is also common in weeping silver solder connections on copper boilers.


----------



## Lakc

I wasn't questioning your fix, just trying to expand my knowledge of weld failure mechanics.


----------



## kvom

Got a delivery from McMaster, so started piping in the smokebox.  Here's the result for the steam delivery:






Kozo just has the delivery pipe off to one side, while this boiler has it centered.  The elbows are thus needed to clear the petticoat.  I used compression fittings and 3/8" OD tube as per Kozo's spec., but I'm not sure how easy it will be to remove and reinstall  with the smokebox present.  The tube is quite stiff, and will need to flex a bit to allow the compression nuts to be threaded on.  I'm thinking I'll anneal the tube after I take it off.  

I have the beginnings of a blower pipe done.  Using 1/4" OD tube through the hollow stay with a compression fitting in the smokebox end.  Still not sure how to construct the blower component past the fitting, as I've seen several options.  On the backhead side I'll have a union that will allow the pipe to be pulled out from the front if needed.  

I have a Locoparts globe valve for the blower.  Looking at how to connect it between the blower pipe and the turret.  I reinstalled the turret and throttle to check for possible routing and have some ideas; looks as if an elbow on the bottom of the turret is the best connection point.


----------



## SilverSanJuan

Lookin' good kvom.  How will you be sealing the smoke box around the steam inlet pipe.  Your "T" is also slightly different from Kozo's design.


----------



## kvom

SilverSanJuan said:


> Lookin' good kvom.  How will you be sealing the smoke box around the steam inlet pipe.  Your "T" is also slightly different from Kozo's design.



The photo doesn't show the saddle installed with the smokebox.  The smokebox has two holes in the bottom, one for the steam inlet and another for the exhaust.

The tee design was modified to  make fabrication simpler.  Trying to make it in two pieces soldered together would be very difficult given the size of the pieces at this scale.  The vertical part of the tee is the  main support for the smokebox, so my round exhaust extension does the same thing.  The exhaust nozzle screws into it and secure the smokebox to the tee very well.


----------



## SilverSanJuan

Ah yes.  I see.  That makes sense.  Thanks.


----------



## kvom

I spent the afternoon in the shop building the blower nozzle, based on one I saw at Bob Harpur's shop a while back.  Here are the components:







The "body" was made from some 1.25' round brass bar, the top from 1/8" sheet; the inlet is a 1/16NPT to 1/4" tube adapter from Locoparts.  The exhaust holes are 1/16".

Assembled with 5-40 screws:






And positioned on the exhaust nozzle:






Bending and soldering the copper tube is for the next time.

I also annealed the steam delivery tube, and that made it much easier tore-install.


----------



## kvom

Little bit of work recently.  I remade some parts of the throttle control to make it a tighter assembly, and also drilled/tapped a hole in the bottom right side to supply the blower.  I'll get some fittings at Cabin Fever next weekend from PMR to attach this supply and a globe valve to the blower tube shown in the photo:






The hole on the left side of the turret will supply the steam whistle eventually.  I still need to figure out the placement and supply to the pressure gauge.

I also managed to get the supply tube bent for the blower in the smokebox.:






The bender I'm using doesn't make sharp radius bends, so it took a bit of trial and error, plus annealing the tube to get it to fit and stay within the smokebox boundary.


----------



## Lakc

Since almost all I know about steam locomotives has come from this thread, please correct me if I am wrong, but you look dangerously close to lighting a fire under this.


----------



## kvom

Pretty close.  I need to finish piping for blower, pressure gauge, water glass, lubricator, one injector, and one side of the tender.  I'll be buying a bunch of fittings at Cabin Fever (mostly elbows, plus some valves, and new boiler checks).

This week I'm wanting to put the loco onto the treadmill to test the throttle using compressed air.  It's too heavy to lift off the stand and awkward to attach hoisting slings, so I'll need to work out something to do that safely.


----------



## cncjunior

I am curious there KVOM about your blower ring.  First off, nice job on the ring.  I quickly fashioned one just to get a loco running so that the public wouldn't be disappointed with not having a steamer to be pulled by.

What my question is have you tried your ring with pressurized water to see if the nozzles aim the steam up the stack?  I have had one where a single nozzle was aimed badly and had a reduced draft from a small pressurization in the smoke box.  Were the small nozzles drilled on a slight taper forming a cone in the center of the stack?  I know a pain in the back side question.

Looking forward to seeing this guy steam.

Daniel


----------



## kvom

Holes are drilled straight down at the same time and not otherwise aimed.  The design perforce has them parallel to the exhaust.  We shall see how it works.


----------



## SilverSanJuan

Nice progress kvom!  I'm also interested in seeing how that blower performs.  Kozo's original design for the 3/4" scale version is just a 'J' tube aimed up the stack.  I imagine that may not be enough for the larger scale locos?


----------



## kvom

Just returned from Cabin Fever with a few goodies for the loco.  Sack of fittings from PMR to help finish the piping.  I also exchanged the Locoparts water glass for the shorter version;  this will stick up less high and make piping it to the boiler less convoluted.  I also arranged with Railroad Supply to take back the bell casting kit I bought from them last year as partial payment for their castings for the front lantern.  Because of the spacing error on the steam dome, I won't be mounting a bell on the boiler.

Since I flew up this year I wasn't tempted to bid on anything at the auction.  I did buy a 0-1/2" Albrecht keyless drill chuck on a MT2 shank that should handle most things on my lathe tailstock.  Up til now I've been switching between a 0-5/16 keyless chuck and a 1/8-3/4 keyed chuck, the latter with a worn shank that holds less well than I would like.

I also picked up some 32 tpi hacksaw blades; these fine blades are best for cutting copper tube and leaving little if any burrs.

Finally I bought a package of the 5 issues of Digital machinist that describes construction of the gearless clock thatr a couple of people I know are building.  This looks like a good project to do that won't take much time and can be pursued when engine building gets tedious.


----------



## kvom

Spent a few hours hooking up the blower line to the turret.






It might have looked neater with an elbow since the tube bender I'm using has a fairly large radius, but this should work for now.  Valve is from Locoparts.

I also installed the smaller water glass that I traded for at Cabin Fever.  The lower height will make the steam pipe connection much straighter.


----------



## kvom

A bit more progress today.  First, disassembled the smokebox piping and placed the saddle and smokebox back on the engine.  In the past I kept the saddle and smokebox assembled, put them over the tee, and then pushed the boiler tube into the smokebox.  With the boiler already in place, I decided to place the saddle on first, and then try to slide the smokebox over the boiler and  then re-attach.  Still took some effort, but I got there in the end.

The assembly of the smokebox innards went pretty easily.  The two pipe compression joints were easy to line up and accessible (I had left the boiler ends attached).  I needed to use a socket on an extension to screw in the nozzle through the stack opening.






Then I was able to get the top pipe on the glass connected to the boiler.  I had cut off a piece of copper tube using #1 eyeball to measure, expecting to trim it, but it ended up fitting as is.  What were the chances?  Only had to anneal it once to get it bent correctly.






I had been planning to make the water supply run from the injector to the boiler today now that I have horizontal check valves.  However, the local Ace hardware was out of 1/8 elbows, plus I'll need a 1/8-1/16 reducing bushing.  So I ordered some more stuff from McMaster and called it a day.


----------



## kvom

Bit more progress today after UPS delivered some fittings from McMaster:






Not the prettiest job of tube bending.


----------



## rkepler

I'd put a valve between the boiler and the check valve, that way if the check starts acting up while the boiler is under pressure you can close the valve and open the check.  You might have one there already, I can't really make out the details there.


----------



## kvom

rkepler said:


> I'd put a valve between the boiler and the check valve, that way if the check starts acting up while the boiler is under pressure you can close the valve and open the check.  You might have one there already, I can't really make out the details there.



I considered that, but was advised to avoid any extra sources of turbulence in the water path that might "annoy" the injector.  It will not be difficult to add one at a future date though.


----------



## SilverSanJuan

Good to see your continuing progress.


----------



## rkepler

kvom said:


> I considered that, but was advised to avoid any extra sources of turbulence in the water path that might "annoy" the injector.  It will not be difficult to add one at a future date though.



It worked just fine for me, and I think my injector has to lift the supply a bit more than yours.  I found an older construction photo showing my install, it worked very well.


----------



## kvom

I had a bit of a disaster yesterday; I transported the loco sans tender to the club as a "show and tell" for a guest run day, and on the way back the loco broke free of its restraints in the truck.  It didn't derail but rolled back and impacted the tailgate with the rearmost part, the sight glass.  No other damage but the glass is toast.  So an expensive lesson and a project to use better hold-down strategy.


----------



## SilverSanJuan

That's frustrating.    That's the site glass that you just bought isn't it?  Do you have a spare?


----------



## ConductorX

The loco was in the bed of your truck?  It broke free?  

How long is this engine?  How much does it weigh?

I just looked at the photos and the electrical outlet box.. I estimate about 4 feet long?  It is a much bigger model than I thought.  :bow:

"G"


----------



## kvom

The front restraint is an angle iron with a piece of 1/2" square bar screwed to it.  The bar has a hole for fastening to the front coupler pocket.  The screw came out, and the secondary hold-down, a ratchet strap, broke.  The loco did not derail, just rolled backwards until the water gauge hit the tailgate.

The loco and tender are each 3' long, and when hooked together just fit in my 8' bed with a toolbox taking up some space in the front.  Had I had the tender hooked to the loco things would been fine.  I am going to loctite the screw on the front and use a much stronger ratchet of other holddown in the future.  The loco probably weighs around 250 lbs at present, and the tender about 200.


----------



## kvom

Spent 6+ hours in the shop working on piping issues.  After a few different tries, I ended up with this for the injector water supply:







To get the barb sufficiently above the track I needed to make a 1/16M x 1/8F adapter from some 7/16 hex bar (dark brown fitting).  The flexible hose will only be a few inches long to connect to the tender's hose barb.

The turret is finished for the time being.






I ordered a different pressure gauge from McMaster, one with a 1/8NPT connection.  This one has 1/4NPT, and necking it down with fittings makes it too high and too heavy.  I moved the water gauge connection to the rear boiler connection and used the front for the gauge.  When the replacement water gauge arrives I'll need to redo the upper pipe.

The tee pipe from the left of the turret is for hooking up the steam whistle with an extra port in case I add something later, such as steam operated cylinder cocks.

Assuming that the water gauge and pressure gauge arrive this week, I need only hook them up and do the piping for the lubricator to be ready to fire the boiler, possibly this weekend.  I also need to up work on the tender for the left side water supply.


----------



## rkepler

What length and diameter of glass do you need?  I've got some 1/2" redline on my desk cut to 2.845 or so.


----------



## kvom

rkepler said:


> What length and diameter of glass do you need?  I've got some 1/2" redline on my desk cut to 2.845 or so.



The glass is what survived; but all the valves broke.


----------



## doubletop

The glass is quick easy and cheap to replace but......

I'm new to this but I see some of the arrangements people have for transporting their locos, even the guys who have been in the game for years, and wonder how well it would do in a crash test dummy situation.  

Just think what a 200lb mass is going to do even in  minor fender bender. A broken sight glass would be the least of their problems, but I'd guess they could well be beyond caring.

........back to the show

Pete


----------



## SilverSanJuan

Nice bit of progress, kvom.   It would be awesome if you were able to put a fire in her by the weekend.


----------



## kvom

Fired the boiler for the first time at the CSP&P track roundhouse.  Thanks to several fellow club members who provided, in addition to advice, kindling, coal, a coal scoop and poker, and load of a stack blower.  It took a while to get pressure up, but eventually the needle came off the bottom.

Things that worked well:

1) The 100 psi safety let loose with the pressure gauge reading 100.
2) Superscale economy injector fed water into the boiler from the tender
3) Steam blower worked very well

I wanted to move the engine under steam to the turntable and back.  But when the engine had moved about 3 feet the gasket between the throttle tube and the turret let loose and I lost all the steam pressure.  We quickly dumped the fire and called it a day, time for lunch.  I didn't take any pics myself, but some fellow members and friends got a few.  I'll post some when they mail them to me.

Things that need fixing:

1) The throttle-tube.turret junction.  I was actually most worried up front on this since if the connecting bolts are really torqued down they squeeze the gland (o-ring) around the throttle rod too tight.

2) The SS grate is a tad too long and expanded so that the grate was tight in the firebox.  This made raking out the fire awkward.  I'll take a bit off each grate bar for the next time out.

3) One of the Locoparts blowdown valve leaks a bit


----------



## SilverSanJuan

Congrats!  Great news on the reliefs, injector and steam blower. 

To bad about the throttle though.  How do you plan on solving that issue?


----------



## dreeves

Glad to hear you had a great day.  Now put your hand out to get slapped for no video.  Lol

Dave


----------



## kvom

Here's a photo a friend shot:


----------



## doubletop

All in all a great day, you'd expect a few niggles first time out. I bet you are pleased with yourself?

Pete


----------



## kvom

Been a while since the last update, but I haven't been entirely idle.  I re-jiggered the connection between the throttle tube and the turret to use separate bolts from those for the gland.  With a new gasket in place I can tighten down the connection without making the gland too tight as well.






I also piped the right side injector.






My tender didn't include a water valve on the right side, so I've been working to supply one.  Everything is in place except for the need to make a long spindle on the valve.  That work has been sidelined by need to work on my Jeep in preparation for a trip to Moab, Utah next week.  So no more progress until June.  Other than that I do need to prime the lubricator before attempting a second steam up.


----------



## SilverSanJuan

Looking very good, sir!

What will you be using for boiler lagging when you come to that?

Todd


----------



## kvom

Not sure if I will use any lagging as it's relatively ineffective at these scales.  But I will need to space the jacket a bit, so cork might be the ticket.  Sheet lead would be excellent for traction.


----------



## kvom

Haven't posted for a while because of vacation plus working on Jeep stuff.  However, I did manage a few tasks including getting the right side water valve in the tender and priming the lubricator.  Also installed a valve in the bottom for draining the tender.   I'm also working on a tool to clean the flues.

So tomorrow I plan to fire it up for the second time.


----------



## kvom

Got to run the loco around the club's yard loop a couple of times, and found a couple of issues.  One is that the steam pressure in the dome wants to force the crank arm on the throttle valve to open.  Thus the engine wants to take off full speed, whereas I really only need to crack it a slight amount to start.  So I'm thinking I need a notched quadrant on the throttle.

The other issue is that this small boiler doesn't have a lot of steam capacity, so I will likely need to keep busy feeding it coal.  Second try around the loop I lost the fire after only going about 100 yards, what with having to hold the throttle I couldn't easily easily manage the shovel.  Had some suggestions that perhaps the grate bars aren't far enough apart, so I'll look at that this week.

OTOH the engineer-side injector worked correctly, so some positive news there.


----------



## cncjunior

Hi Kvom,

A throttle that wants to push itself wide open is not a good thing even with a quadrant that has notches.  There might have to be a redesign on the throttle assembly required as this is a safety issue.  I am part of a club that has steam locos that pull passengers around a mile of track with safety rules that talk about risky throttles.  Not being familiar with Kozo's designs I cannot say where the problem is.

IMHO with the firing of coal and the grate, I would say about 1/8" to 3/16" gap between the bars for your size engine.  You will definitely have a learning curve not only with your engine as well as the type of fire it needs.  Perhaps it needs a deep fire similar to a hay stack or one that is light in the front and thicker at the back.  When you do figure out the mysteries of your engine it will be a delight to run I am sure.  Managing that boiler for steam is all part of the challenge and joy of running a steam loco.

Propane firing is easier to begin the learning curve of firing a steam loco and yet when you get the hang of it, it seems easy compared to coal firing.

Hang in there and I am sure you have folks that can help with pointers on the intricacies of steam running.

One little note about the British steam train running is that upon reaching speed they would have the throttle full open and just use the reverser to change speed.  Works the charm.

Cheers,

Daniel


----------



## kvom

The grate spacing is 1/4", and my club members suggest that 5/16" may be better, given the size of the coal being used.  Tightening the packing may be a partial solution to the throttle.  When cold it's fairly stiff, but ball valves apparently loosen up when hot.

One of the next steps will be to cut notches for the reverser quadrant and see if it runs OK "notched up".

I also found out that the foot-operated brakes work well, at least on flat ground.


----------



## cncjunior

It is funny you mention the foot brake.  My first few times engineering a loco I pulled out the emergency foot brake too.  I think it goes back to the go cart days with no brakes.

The grate size as you mentioned is determined by the coal size, however, too big a coal chunk and you have larger air voids between the coal chunks.  I am not sure how big your fire grate is for your engine.  Smaller coal chunks like 5/8" - 1/2" cube might be better.  There is a balancing act between coal size, air pocket size, grate area, and grate bar gap.

It is odd that your ball valve has a tendency to open up under pressure.  Usually ball valves are known for holding their position.  Is your valve on the wet side or dry side of the super heaters?  Never mind that question as I looked back and there aren't any superheaters.  At my club we tried ball valves after super heaters and found that the teflon gaskets disintegrated with the super heated steam.

Cheers,

Daniel


----------



## kvom

Did a few things preparatory to trying another steam up.

I had borrowed a blower for the stack from another club member, but I need to have my own.  So found  this Dayton exhaust blower on eBay for under $40 shipped:







To have it sit securely on the stack I turned down a scrap aluminum coaster to have a spigot that fit the stack, then bored out the center to 1.5":






Then wired to a 3-prong plug/wire from an extra PC power cable, and it seems to move a decent amount of air.

Another needed tool was a rod to clean flues.  For the brush portion I bought a 3/4 inch "fixture brush" in the plumbing section at Lowes for $3, then used the bench grinder to grind the bristles down to a "not too tight" fit to the flues.  After cutting the handle off, I made a steel ferrule and welded the brush shaft to it.  Other end of the ferrule was tapped to screw onto the SS rod.  Finally turned a simple handle from aluminum and used Loctite to fix it to the rod:






The rod is 3/16" diameter and flexible enough to do all the flues except the bottom center one from the smokebox.  That flue will need to be cleaned from the firebox end.

The other mod was to use a T fitting for the pressure gauge plus a ball valve.  The valve when open vents the boiler when filling with water.  It can also be used to vent steam at the end of the day, possible for steam cleaning the loco itself.


----------



## stevehuckss396

Incredible amount of work you have into this thing. Building a loco is like running a marathon.


----------



## kvom

I haven't spent a lot of time on the loco for a while, but today made a quadrant for being able to lock the throttle in place.






Now I need to figure out a spring-loaded handle and mechanism to engage the teeth of the gear.  I've seen a few examples in the past.  With the present throttle geometry there are 4 positions between closed and full open.


----------



## kvom

Next step in the throttle quadrant is the lever to be attached to the bar.  Played around with various options in CAD and came up with this.  First cut the profile with the CNC mill:






Then manual milling to get to this:






That was all for today.


----------



## kvom

Continued work on the throttle lock the past couple of times in the shop.  Here's all the pieces:






Then took the plunger to the CNC mill to profile the end to match the quadrant gear:






The square end of the plunger is 3/16" and the endmill is 1/8.  Then a bench assembly to test the "action".






The handle and plunger were connected with some solder wire as a temporary test.  On the loco I will use some stiff wire.  The spring is salvage from a ballpoint pen, and seems just the right force.  Cheap to replace if it wears out.

Installed on the throttle bar I have a problem.  The quadrant gear is not a tight enough fit to the clevis resulting in quite a lot of slack in the throttle position.  I think soldering it to the clevis is the best solution.


----------



## stevehuckss396

As always "Nice work". All in brass?


----------



## steamin

Greetings,
In regards to your stak blower; I did the same thing for my steam traction engines. Make sure you have some fresh air coming in at the stak or you will melt down the squirrel cage from the intense heat from the boiler as I did. The cage got sooooo out of balance that I had to discard that one and replace it. At first I just put a wedge of wood into the stak along with the blower. Then I made an adaptor from duct work that bolted to the blower and fit snuggly into the stak. I punched ten 1/4" holes around the perimeter to draw in cooler air to tone down the hot gases coming from the boiler. Awesome job on the loco !!
Regards, Larry


----------



## kvom

Last two shop sessions were devoted to machining the steam whistle.  This is from an old Locoparts kit that I bought from a fellow club member.  If you were to buy this whistle today it would be already machined with a cast brass core rather than the aluminum I have.  In any case, it was necessary to machine the center casting and the brass "cup" to fairly precise dimensions.  Here's the parts prior to assembly:






The casting diameter needed to be a press fit to the 1/5" OD brass tube, whose ID I measured as 1.435".

Assembled, it looks like this:






Here's the approximate position for mounting under the left running board.  Obviously I have to clear the lifting link.






Locoparts sells a 6" long model that might be a better choice for small engines, but I think it will fit.  Next session will be to fabricate some mounts for it.


----------



## kvom

I started work on brackets for mounting the whistle under the running board.  Started with some brass, 3x4x1.4" and mounted on a fixture place.  A bit of CNC milling to get this:






Removed from the plate, cut off the holding tabs, and cleaned up:






Then sliced in two with a slitting saw:






Then test fit on the whistle:






Next time out I'll drill/tap the brackets for some 8-32 screws, and then drill the runnijg board.  I also mocked up the whistle valve position, so once I can hold the whistle in position I can pipe the valve to it.


----------



## kvom

Got the whistle mounted and piped, so hopefully Wednesday I'll steam up again and try all the updates since the last time.


----------



## kvom

Third try at steaming up today.  I still had a little trouble getting the fire to stay lit at the start but finally got it going pretty well.  At 60 PSI I gave the new whistle a try with "mixed" results:

[ame]http://www.youtube.com/watch?v=iKzGCouVTg8[/ame]

As can be see from the comments, the whistle valve stuck open meaning dump the fire and pressure.  Fixed the valve (hopefully) but it was too darn hot and too little time to fire up again today.


----------



## rkepler

kvom said:


> As can be see from the comments, the whistle valve
> stuck open meaning dump the fire and pressure.  Fixed the valve (hopefully) but it was too darn hot and too little time to fire up again today.



Shame, that.  I've only made one loco but have valves to cut out most every line including the brakes, whistle and both water lines (valve after the check - if the check sticks I can cut it off, fix it and return to service.


----------



## SilverSanJuan

Well, at least the whistle sounds really good.


----------



## kvom

A friend discovered that the whistle valve was installed in the wrong direction, so that the steam pressure opened the valve.  I reversed it and that solved the problem.

I still failed to get around the yard more than 1.5 times before losing both the fire and water.  Too many things going on at once for a beginner engineer, plus the tiny firebox door is a problem for feeding the coal.  The injector position is also a problem as it's very hard to see from the tender with the running board in the way.  In the steaming bay I have no problem getting the injector to feed water, but whether I can make enough steam to drive it and the loco at the same time remains a question.

I'm thinking I might move the injector above the running board.  It should lift that high, but the water intake would be above the bottom of the tender.


----------



## Lakc

Its moving, this is the fun part


----------



## kvom

I brought the loco home this week after sitting at the track for a couple of weeks.  Today I gave the steam dome and its top a coat of hi-temp paint, and the top was starting to get a bit rusty.  Of course I should have painted it right after it was welded on.

I also decided to break the grate into two pieces vs. the single piece grate Kozo designed.  It's to hard to get in/out and awkward to dump the fire.


----------



## kvom

Did a bit of shop time the last few days, including starting on the headlamp.  Rather than build one per Kozo's book, I bought a casting kit from Railroad Supply.  It will be a good deal larger than the plan, but the result will likely be better than I'd do on a scratch build.

Here's a look at the parts as delivered:






Cleaning up the aluminum case casting is the biggest part of the work.  In order to true up the sides and bottom, I used the back as the initial datum as it was quite flat and smooth.  Holding it in the vise presented some challenges because of the odd shape.  Here's the setup I used to mill the bottom as well as drilling/tapping 4 mounting holes:






The lens provided is a round piece of 1/8" thick lucite.  It was about .04" too large in diameter to fit the cast bronze frame, so I had to file it down a little at a time until it made a good tight fit.  With the frame mounting holes drilled and tapped for 5-40 screws, a little test fit was in order, including the aluminum reflector.






The reflector is parabolic and should project a fairly tight light beam, esp, with some polishing.






The chimney vent is a bronze casting that will require some filing.  It's attached to the case by a 10-32 acrew, so a hole in the center needs to be drilled and tapped.  It was difficult to hold very securely in the vise, so I milled the bottom flat using .01" DOC and feeds on in the y direction.






Test fit of the vent on the case:


----------



## stevehuckss396

Is this going to be a gas fired light or will it be electric?


----------



## kvom

stevehuckss396 said:


> Is this going to be a gas fired light or will it be electric?



Electric, probably LED of some sort.  One of the club members suggested a part# that I have since forgotten.


----------



## Lakc

Calcium carbide is hard to find these days, but it does give that authentic glow.


----------



## kvom

The base of the font (where the glass chimney mounts) is specified to be threaded 3/8-24 to screw into a spigot on the baseplate.  However, the diameter of the casting is a bit smaller than 3/8".  In any case, I made a little temporary split collet from some 1" aluminum round, mounted it in the lathe, and ran a die over the shaft.  Not great threads, but they will suffice to keep the font in place.







Then drilled the baseplate to attach both to my mounts and to the bottom of the lantern casting.  Since the casting will cover two of the mounting screws, the lantern will be attached up from the bottom.  Rather than using 5-40 screws in from below, I decided to use set screws in the casting and nuts below.






As can be seen, the lantern is pretty large vs. the stack.


----------



## kvom

Started to work on the reflector, which needs to be polished up a bit on the inside and than have a 3/4" hole drilled to admit the font and chimney.  First step was to CNC mill a 2.9" hole in a 4" aluminum coaster.






The hole secures the reflector by its flange.






The reflector is then clamped to the fixture using the bezel casting.






Then I could mount the fixture on the lathe after boring some soft jaws.  Now I can spin the reflector while applying emery paper and the like to try to get better reflectivity.  Started with some 320 grit.  More next time.


----------



## doubletop

kvom said:


> Electric, probably LED of some sort.  One of the club members suggested a part# that I have since forgotten.



Hi

So if you are going to fit a LED why do you need to spend time polishing the reflector?






12V MR16 type 50mm diameter

Pete


----------



## kvom

Decided it was time to finish up the cab.  So milled up the window frames for the side-front window and attached them to the sides using #4 drive screws.  Frames are made from 1/8" brass sheet and will stiffen up the sheet metal.






I neglected to count the number of holes in the sides and ordered only 1 box of 100 from McMaster.  Not enough!  So this task will halt until I get another order in.

The heads ( mimicing rivets) are probably a little large for the scale, but they do match the rivet heads in the tender.


----------



## kvom

Having won some free software (Cubify) from a contest on another site, I undertook my first 3D machining part, the base of the steam dome cover.

  After purchasing a 2.5" cut from 6" round bar 6061 aluminum, the first job was to reduce the thickness to 2.15" and the diameter to 5.25".  I turned it between centers using a 1/4" screw as a lathe dog:






Next, machined soft jaws on the CNC mill to hold the blank:











Next, milled a through pocket to permit the base to slide over the dome.






Then reversed in the vise and roughed the 3D cylindrical surface using a 5/8" 2-flute HSS endmill.






Then did the finish pass with a 1/2" HSS ball mill.






It needed some fitment using the Bridgeport, but now fits well on the boiler.






I still need to fit the cover to the base and paint.


----------



## kvom

Started paint on the cab sides, and while waiting for that to dry worked on the steam dome cover.  I am using the center cap of a Cragar 8-lug wheel as the cover.  It's the correct size and has a nice  black gloss finish.  I needed to cut a slot in the bottom for the throttle tube.  However, it's difficult to fixture thin metal, so I came up with the following.

I had a chunk of 5.5" aluminum tube with 1" thick walls that I picked up some years back as scrap.  I turned the OD down to 5.04" to form a tight sliding fit for the cover.  I mounted this on the Bridgeport with the rotary table:






Then slid the cover on and drilled tapped two 8-32 screws into the sides.  These holes will be used to secure the cover to the base 






Now mill the slot.






And test fit.


----------



## stevehuckss396

Still following along with much interest!  Thanks for the update.


----------



## doubletop

Me to....

Pete


----------



## kvom

Test fit of the sides and front of the cab.






I picked up some 20ga sheet yesterday that will hopefully turn into a boiler cover and cab roof in the future.


----------



## ozzie46

Looks great. Still following along as well.

 Ron


----------



## kvom

Little more progress.  Made two brackets to attach the steam dome cover to its base






Next, started on the boiler wrapper and insulation.  Boilers of this size don't normally benefit that much from heat insulation, but in this case the smokebox diameter is 1/2' greater than the boiler tube.  So I wanted to pad the boiler so that the handrail stanchions would line up easier between the smokebox and boiler cover.






The material I'm using is a ceramic sheet from McMaster. http://www.mcmaster.com/#93285k18/=pgpafu.  Good up to 2300F, so should handle the 350F from the boiler.  I ordered the 1/8" thickness, but will use 2 or 3 layers to build up the diameter.  It's quite soft and easy to cut with scissors or x-acto knife.


----------



## kvom

I've been working on the boiler casing and associated fittings.  After cutting some 20 ga steel sheet to size (21x16"), I got a buddy to cutout the hole for the steam dome with a plasma cutter.  Then drilled mounting holes for the sand dome, handrails, and water inlets.  Then rolled using a borrowed slip roll.

I'm able to slide it over the boiler taking a bit of care, and then remove it again without creasing.  Then I gave it a coat of primer followed by paint (black implement paint from Tractor Supply).  Once dry, I installed the handrail stanchions that I bought from Locoparts a while back.  They take a 3/16" rail, so I used some 3/16 drill rod for a test fit.






The issue I'll have on assembly is that when the stanchions are screwed down the rails get clamped tight, and I can't adjust them.  I also don't know where the power to the headlamp will be located, so if the switch is in the cab I want to run the wire down the handrail. I also want to extend the rails to the stanchions located on the smokebox, and that's likely to be imperfectly aligned.

So my plan is to use brass tube for the handrails.  Should be easier to bend where necessary.  Need to order some before putting the cover on.

I also bought some 1/16x3/4" brass strip for the boiler bands.


----------



## stevehuckss396

Damn man, that looks really nice.


----------



## kvom

Trial fit of the boiler casing today, since I got the brass for the handrails and boiler bands.  Getting the casing on was a struggle since the bottom edges would dig into the insulation.  I finally tied the insulation sheets around the boiler tube  with twine.

The holes for the water inlets are a bit off and will require some filing.  I installed the cab and running boards so that I could locate the two holes in the cab front where the handrails pass through.






If I had it to do over I would finish the casing and install it with the boiler off the loco.

I also noticed from the photo that solder joint on the injector steam supply has come undone.  argh.


----------



## kvom

After some downtime for the holidays, a bad cold, and a business trip, I managed to get a good fitting boiler cover.  A friend cut it out for me on his plasma table from 22ga sheet steel.






Took it off afterwards for paint.


----------



## Lakc

Thats looking an awful lot like a locomotive. 
Thanks a bunch, learned tons in this thread.


----------



## kvom

After fighting a cold for a month, and general winter ennui, I decided to get back into the shop a little and start re-assembling the engine now that the boiler jacket in installed (and painted).  First problem encountered was that the throttle quadrant broke apart.  if you followed this previously, I originally made it in two separate pieces, but that was too lose.  Then soldered them together, but it seems that my solder job was poor.  So I decided to make it from a single piece of brass.

First op was CNC machining the gear teeth profile.  Final pass was 3/64 2-flute endmill, my smallest:






Then a bunch of manual ops on the Bridgeport to get to the final shape (sorry for the fuzzy photo):






Then installed:


----------



## kvom

After painting the boiler jacket and getting it back on with its bands, I started to reassemble everything I removed to install the jacket.  Plus I could install the steam dome, sand dome, cab front/sides, and the handrails.  My steam feed tube to the right side injector is fubar, so I'm waiting for a couple of new unions to remake it.  I also added a second notch on the reverser quadrant to see if notching up will help reduce steam consumption.






From the following photo you can see that the headlamp still needs work and that I messed up aligning the stanchions on the boiler with those on the smokebox.  Plus my painting is crap.  I did remake the number plate engraving the numbers much deeper (.06).  The first try was only .006 deep and the background got scratched up right away.






I need to take it out to the track soon for some solo practice keeping the water and fire both going for more than one loop around the yard.  

One problem is that the injectors are too far inside the edge of the running boards so that I can't see the drain pipe.  I am making a jury-rig system with an elbow and a piece of brass pipe to stick out beyond the running boards.  An alternative would be to cut a window in the part of the boards that are inside the cab.


----------



## kvom

So a month ago I took the loco to the club for the annual hydro (its second).  Fail!  Cylinders full of water and no pressure.  Pulled the steam dome cover and the throttle valve was closed, so I had to assume that the valve's mounting plate had gotten loose.  Sure enough, two of the 4 screws that hold it to the boiler were loose, as if the threads were stripped.  Took the loco back home where it's sat for a while.  I couldn't think of a better or easier way to mount the valve, so today was time to fix it.

Originally I'd tapped the 4 mounting holes 8-32, mainly because that was the only size of SS screws I had.  I figured that the steam pressure would press the mount down anyway.  Here's the view inside the dome:






The large hole is the pipe to the clyinders, and the two rear holes are open to the boiler.  The mounting plate sits on the bottom in this orientation, held by 4 screws.  The large hole is where the globe valve screws in.






The underside of the plate has a channel connecting the valve to the steam pipe.






Looking at the gasket reveals the problem.






To make the plate more secure, I decided to drill out the tapped holes and re-tap to 10-32.  Problem is that the dome is 3" deep, and my drills and taps are less than that.  Checked out McMaster for a 6" #21 drill bit and 10-32 tap:






To ensure drilling and tapping straight, I used some scrap aluminum bar with two tight fitting holes for the drill and tap.  Marked the drill with some tape to get the holes 3/4" deep.











Off to the hardware store to find some SS screws then a new gasket, and we'll see if it will pass.


----------



## SilverSanJuan

Did the gasket blow out?  Picture is kind of fuzzy.  What is the gasket material?

Todd


----------



## kvom

Gasket is a paper-based material I got at Ace Hardware.  Coated with a mixture of steam oil and graphite.  I used the same stuff on all the gasketed joints without any problem, other than this one.  Since the plate was loose I suspect that steam or water got underneath and split the gasket.


----------



## kvom

After the last post in May I took a break from the A3.  But now that it's cooler and steaming is more comfortable, I decided to try to fix the throttle leakage.  The plan is to cover the channel in the bottom of the throttle baseplate so that there is more "meat" in the paper gasket.

The cover is a plate made from some 304 SS sheet that I machined down to .065" thickness,  Drilled the mounting holes on the Bridgeport and then the profile on the CNC mill.  To keep the throttle rod at the same height I took .06" off of the bottom of the throttle.







I then fastened the cover and baseplate together with red high temp RTV (good to 600F).  Then made a new paper gasket and reinstalled everything in the steam dome,






Hope to retry the hydro test on Wednesday;  if I succeed may fire it up too.


----------



## kvom

After many attempts to seal the throttle plate with various types of gasketing, I've decided to cut off the steam dome.  A plate with a channel between the dry pipe and the valve mount will be remade and welded to the top of the boiler, and a removeable steam dome will be fabricated.

First stage of rebuild is to get rid of the old dome, which is welded to the boiler.  Buddy with plasma torch made quick work:











Got it home and applied face mill to clean up the cut.






The dry pipe is threaded 1/4 NPT, so I tried this setup.  I think it should work.






John from the club has some steel pipe that's 3.5" OD and 3/8" wall.  I redid the SW model to use a flange inside the dome for attaching to the boiler, and it appears everything will fit:






Bottom disc is welded to the boiler plate and then drilled and tapped.  An almost identical piece is welded to the bottom of the main pipe, and drilled clearance to match.  The flange for the throttle pipe is welded to the main pile, and then the holes are drilled.  The lid is drilled for clearance holes to match the tapped holes in the upper edge of the dome, and the lid has NPT tapped holes for the safeties and for filling the boiler.

The new dome will be slightly taller than the old, as well as wider (old OD was 3.25").  With the old mounting plate not covering the top plate of the boiler I plan to drill an extra steam supply hole as the two small existing holes will be somewhat blocked by the flange.

The throttle tube and turret will rest slightly higher than before, meaning a good opportunity to redo most of the piping.  Given that the Superscalte Economy injectors are lifting, it makes sense to place them in the cab where the drain pipe is visible.


----------



## kvom

Machined the mounting ring for the steam dome.  It will be TIG welded to the boiler, then drilled and tapped.  Show in position:


----------



## kvom

Got three main pieces cut and ready for welding.


----------



## kvom

Got the welding done by a buddy.  Here's the base ring welded to the boiler, drilled and tapped:






A view of the bottom ring of the dome body, drilled to match the base plate.  The notch is to clear the elbow.






An interior view:






Mounted on the boiler with the lid; safeties and fill plug installed.






Next is to fabricate and weld the mount for the throttle tube.


----------



## kvom

Short shop sessions today.  First, measured and drilled the hole in the dome through which the throttle rod will pass.  It's 1/2", but could be enlarged is needed.

Then setup on CNC mill to smooth welds where the mounting flange will be welded later.


----------



## kvom

Made the mounting flange for attaching the throttle tube to the steam dome.






The 1/2" drill bit will align the two parts together for welding.


----------



## kvom

A friend welded the mounting flange to the dome body, so it was time for some fit checking:






With a little fettling I got the dome cover and base to fit, although I need to install the boiler jacket to be sure.  When I installed the throttle rod mechanism onto the rear of the tube I found that the crank for the valve stem is now too short since the valve sits slightly higher now.  I had made the hole in the dome smaller this time (.5" vs .65"), so enlarging the hole may work vs. making a new crank.

Since I'm going to redo the piping and since the Superscale injectors are lifting, I will position them inside the cab rather than underneath the running boards.  Test fit of the cab looks fine for this by eyeball inspection.


----------



## kvom

I have validated the new throttle assembly via a hydro test to 150 psi last week, and am starting the re-assembly.  Had to order some stuff from PMR and McMaster.  Got the boiler jacket on and the boiler on the chassis.  The good news is that the throttle tube is the same height as before and the cab still fits. 

The smokebox piping will be SS steel tube, since I was advised that coal flue gas will quickly erode copper.


----------



## Lakc

Glad to see this still progressing. Unlike any of my projects


----------



## kvom

My stainless compression fittings and tube arrived from McMaster. The fittings are longer than I imagined, and a quick fit to the loco revealed a few problems.






The one on the steam port on top would interfere with the petticoat, and on the bottom is a tight fit to the blower nozzle.  The connection to the blower nozzle is close the inside wall of the smokebox and would mean a tight bend on the tubing.

Using various fittings I came up with this:






Seems to fit with no issue, although an elbow at the blower nozzle might be good too.


----------



## kvom

I found and ordered a quantity of SS hex nipples on Amazon that can replace the brass ones used in the prior photo.  No luck looking for a 45 degree with mail and female like the brass one.  I think I can make one with 2 female threads and use a nipple for the male end.  OTOH that 45 degree brass nipple is quite thick, and even if it were to corrode it should be easy to remove/replace.

I am reluctant to modify the SS compression fittings at this time, as they are $20 each.  The steam supply setup seems pretty good as it needs only a short curved piece of tube.  The blower side is more awkward, but there is plenty of room forward in the smokebox to make a fairly wide curve.  I'm not going to finalize it until everything else is set, including the valve piping from the turret.

Speaking of which I'm wanting to use brass pipe for the blower valve connection vs. the copper tube I had before, which I felt was unsightly.  The valve (I believe it is from Locoparts) has a female thread on one side and a male solder connection on the other.  To use threaded pipe on both sides I needed to duplicate the tube end piece that had been soldered on previously.  Fairly easy lathe job starting with some 7/16 brass rod.






Spent the rest of the afternoon setting up the CNC mill to thread the many pieces of 5/16 brass pipe that will be needed.  First attempts will be hooking up the blower valve and the whistle.


----------



## Lakc

Would it be a bad idea to use double flare fittings like a brake line?


----------



## kvom

After much fiddling plus discussion with a very experienced builder, I decided to use brass compression fittings along with the SS tube.






Tube bends were relatively straightforward, and there's no interference with the petticoat.  Then I have basically finished up the redo of the piping.  Other than the turret being replaced, I redid the connections for the blower, whistle, and water glass.






A few minor tasks left before next attempted steam up.


----------



## scottyk

Love your build!  I just read the entire thread from the first page, I was hooked couldnt stop reading and looking at the pictures.   You have a incredible amount of work into that loco and should be very proud.   Nice!


----------



## kvom

Short update:  last week I took it to the track for a hydro test on the boiler, which passed.  However, several pipe joints had seeps and need to be tightened.

This week I returned to the track and attempted a steam up.  Still some small seeps, but I had problems in firing.  First issue is that my stack blower is to fast, pulling so much air that the fire gets blown out.  Since I don't have a speed control I restricted the flow by blocking the best part of the output.  Got it heated uop with the needle off the peg, but couldn't get is past 20 psi.  Adding some more coal put the fire out!

Post-mortem is that I likely had too much coal, as it wants a thin bed on the grates.  I found some unburned wood I'd supposedly added to help start the blaze.

I'll try it again soon.


----------



## georgjorge

Hello,

could you be so kind to supply me with the PRR-font? I am using Mach3 to control my home converted super X3 cnc mill.
Best regards
georgjorge


----------



## B36Peacemaker

Kvom, I know this thread is dead, but I'd like to sincerely thank you for documenting your A3 build! It was an great inspiration for me to begin my own A3 in 1.5" scale back in 2017. I read through the entire thread one day in high school after I bought Kozo's book, and watched years of your work come together in a few hours. 

I started with no machining experience at all, and working on-and-off over three years in other people's shops I've completed the tender and locomotive frames, fire grate (first thing I built), tender wheels/axles, suspension and axle boxes, and just today the journal boxes for the tender. Usually I'll work on it for a few months, get sick of it, then come back to the project. Just how my mind works I guess, but I'm entirely committed to finishing it one day! I don't have the luxury of CNC, but I've referred to your thread a few times for guidance.

If you see this, did you ever complete your locomotive? I'd love to see some pictures!

-William Liebbe
Houston, Texas


----------



## kvom

I sort of finished it (no headlight) but decided actually running it isn't my thing.  It's been sitting in the vault at the track for three years.  I probably ought to try to sell it to someone who would run it.


----------



## B36Peacemaker

That's a shame. How much would you sell it for? 

You might have luck putting it on the Discover Live Steam website.


----------



## kvom

I have about $4K in it out of pocket.  Would sell it for that.  The tender is not an A3 tender and would be additional $900.  For the time being I'm not going to the track because of the pandemic.


----------



## johnnyo

I too had started this engine in 2008 and let it sit in my shop for maybe seven years or so while I built many other models. I finally picked it up again last summer after visiting the Finger Lakes Live Steamers and Steam Town in scranton, Pa. I took advantage of the stay at home orders and got it running on air. I am now designing the boiler and using many resources from these sites and steam clubs like The Cinder Sniffers. I have read many build logs, yours included KVOM, and learned much. I just got the Australian model steel boiler code and started reading up. I have seen these boilers built many ways right down to one with 1/4” thick tube sheets and only 3/16” plates. Can I ask you KVOM for some insight to your build? I have a few questions and would love to share my knowledge and experience so far. Heres apic or two.
Thanks
Johnny O


----------



## kvom

Sure, ask away.  I had my boiler built by Godshall.  The error in the plans for the steam dome location was a bummer though.

Your build looks quite far along already and high quality.  I see you have the axle pump installed.  I was advised against it by experienced people at our track.


----------



## B36Peacemaker

What's wrong with the axle pump? Would injectors be preferable?


----------



## kvom

Axle pump takes energy circulating water when boiler is not being filled, but is easier to manage.  I used injectors, which take getting used to.  Ideal is electric pump IMO.


----------



## B36Peacemaker

This thread is now officially hijacked for my own purposes! I will be documenting progress on my A3 build, which is exactly like kvom's, except that I don't have CNC capabilities. Now anyone looking to build this locomotive in the future will have TWO projects for reference! If we hit an image limit, I'll start a new thread.

A buddy of mine let me drive his 2-8-2 Mikado around the club track, which has inspired more progress on my own locomotive. Been working on the brake system for the engine this past week. Today I made the bracket which holds the foot brake pedal in place. Used some scrap 1.5x1.5 CRS, since I didn't have any 1.25x1.25 as the plans implied. Since I hadn't drilled/tapped the holes in the footplate yet, I changed the spacing of the bolts to better fit my wider-than-spec bracket (1.5" instead of 1.25").

This is one of those parts that is an odd shape, seemingly designed to give the first-time builder a hard time! A simpler shape would get the job done, but I decided to oblige Mr. Hiraoka and machine the profile as drawn. Here's the profile marked out:






I drilled the required holes first, so the drill bits wouldn't have to break out of the metal at a weird angle:






The surface finish on the main hole is absolutely atrocious, due to my clapped-out 9/16 drill bit. Plans say to ream, but I don't have a reamer at the moment, and it's not really necessary since the bronze bushings that get loctited into this hole will be turned to fit anyways. This is an example of a non-critical component that can be "close enough" and still work just fine. As long as it works I'm happy.






Next I got creative with the bandsaw, hacking away as much material as possible to spare my endmill the work:






I used calipers and a rule to markup the straight edges, but totally eyeballed the radius. Again, not critical.






I ended up making a few more cuts, but this is basically what I was left with:






Next it's off to the mill to cut away more metal. I lined up the scribed lines with the top of the vise jaws, then milled down until I hit the line:






I repeated this process for all straight surfaces, then roughed out the radius with several cuts:






I finished rounding off the profile with a disc sander, then cleaned up the part with files and sandpaper. The last operation was to counterbore for the rear bolts with my 5/16 endmill:






Finally, I clamped the bracket to the footplate, spot drilled the holes, then drilled and tapped them 8-32. Here's the bracket mounted in its final position:






All-in-all, this one part took about three hours to make. If you're gonna build one of these locomotives, you have to be able to enjoy the building process! More brake progress coming soon...


----------



## B36Peacemaker

Short session at the makerspace to turn the two bushings for the bracket I made yesterday. Don't have any bronze laying around at the moment, so I used some scraps from a chess set I made last year. The "black" pieces had bases made of melted bullet casings that I poured into a steel mold, then turned to shape. The "white" side had stainless bases (white bishop made from .444 Marlin case shown in picture). Anyways, cartridge brass is probably not the best bearing material; but it machines nice and is better than steel-on-steel:






Once I loctited the bushings in place, I re-reamed them by hand to make sure they were concentric. This was necessary since they were not a perfect fit in the bracket (due to loose tolerances and that crappy surface finish):






Finished bracket mounted back on the locomotive. Tested it with a 1/2" rod to confirm the re-reaming had worked. Kinda neat that I've got parts made from casings now; thinking about casting the bell and number plate from bullets as well, just for the neat-o factor.


----------



## 428Bird

Man I just ran across this build and read the entire thing in one sitting. I ordered the book and am anxiously waiting it's arrival. I do have a couple of questions though;

1. Does the book have dimensions for 1.5 scale, or did you just double everything?
2. You mentioned that you needed to build/install brakes. Does the 3/4 scale model not have brakes? If not, how did you design them?
3. Has anyone ever tried to stretch the frame to make an 0-6-0, or add a pilot truck?

Nice work!

Britt Bettell


----------



## B36Peacemaker

Britt,

Kozo's book includes a section in the back on how to scale the locomotive up to 1.5". It guides you through the differences in the two scales. Some components are different than the 3/4" scale version, such as the frame, boiler, pistons, etc., while others are completely new, such as the braking system.

As far as modifying the design, you're on your own! I doubt anyone has tried it; the work required to redesign the loco is probably not worth it.

I see you're from Houston; are you a member of the Houston Area Live Steamers? You'll need a place to run your locomotive eventually! And I know a few guys there that can help you with live steam questions.


----------



## kvom

I'm away from home at the moment, but what I did was as follows.

Any dimensions inside the frame are scaled to the track ratio, 7.25/3.5.

Anything that is outside the frame is 2:1.


----------

