Building Kozo's New Shay locomotive

[SilverSanJuan]

Wow! You made quick work of that! That throat plate looks great. What size torch did you use to anneal the plates?

Todd

 

[crueby]

Wow! You made quick work of that! That throat plate looks great. What size torch did you use to anneal the plates?

Todd

Not sure how to describe the torch size - am using a mapp-gas cylinder with a one piece screw on trigger/nozzle assembly - is a Bernzomatic head, opening is a little under 1/2". I did notice that with the larger copper pieces it took a little while to heat up, the copper really conducts the heat fast (plus it was a little windy out), but I was just getting the areas to be bent up to full temperature, did not matter for the sections staying straight. Once I stood up a couple of the fire bricks to reflect the heat and block the breeze it worked much quicker.

 

[SilverSanJuan]

I have a very similar torch. I'm glad to hear that you are only annealing the areas to be worked. I thought I would need to anneal the whole sheet to prevent warping.

Todd

 

[crueby]

I have a very similar torch. I'm glad to hear that you are only annealing the areas to be worked. I thought I would need to anneal the whole sheet to prevent warping.

Todd

Maybe on very large sheets you would, but these pieces are fairly small, and the whole sheet warms up anyway - copper transfers heat very well.

 

[crueby]

The boiler front end plate machining started with drilling holes for the firebox studs, the blower tube fitting, and starter holes for boring the firetub holes.

In the book, Kozo mounts the front plate (and later the firebox plates) to the lathe faceplate to cut the holes to size with a boring bit (drills this big would never give a clean round hole). However, this is another case where a little ingenuity was needed to do the operation on a small lathe. I could just get the front plate offset enough on the lathe, with the riser block in, but there is not enough clearance to do the same on the firebox plate. So, am doing those operations on the mill, which has a slightly longer reach, plus using the rotary table means the mill cutter only has to reach the inside edge of the hole, not the center. So, I screwed the plate to a piece of wood on the faceplate (same one used earlier to mill the formers), and milled the three firetube holes out to size.

After all the holes were done, checked the fit of the tubes/fittings (third photo). The blower tube fitting does not get soldered in now, that comes along with the firetube assembly later.

Last part of the front plate to make were the two stiffening ribs on the inside of the plate. I trimmed out a couple of cardboard templates to get the shape figured out (the radius of the flange on the plate is a little tricky to match), then cut and filed up a pair of ribs out of copper.

The two ribs interlock to form a 90 degree angle. The ends were filed off at a rolling angle to match the front plate shape.

With the two ribs clamped in place, they were silver soldered to the plate.

Then, the plate was screwed back down to the rotary table, centered up, and the outside edge milled to the dimension needed.

Last, the two firebox studs were soldered on (these take screws from the inside of the firebox to hold it in place).

Next up, simaler steps on the front firebox plate...

 

[crueby]

Did some more on the boiler plates today - started with the firebox front plate and the throat plate. Clamped them together to drill the common holes for the staybolts - drilling them together ensures that the holes will line up properly. As each of the first two holes were drilled they were tapped, with some bolts run in, before drilling the rest - wanted to make sure the plates did not shift while doing the rest of the holes.

Once all size holes were drilled, the sheets were seperated and the firebox holes tapped for the inner end of the staybolts. The throat sheet holes were drilled out to match the outer diameter of the other end of the staybolts - that end has the bolts just slipped through the throat plate and soldered. I still need to go back and bore out the holes for the firebox tubes in the firebox plate - ran out of personal steam before getting that far today though.

Likewise on the back firebox plate and the backplate of the boiler, the two pieces were clamped together and drilled for the staybolts. These two plates get a large hole milled in that will form the opening for the firebox doorway.


The last photo is all the plates at the current stage - still needed to be done: mill in the firetube holes on the front firebox plate (upper left in photo), and mill the outside surfaces on the rest of the plates (only did the edges on the round front plate last time).

 

[crueby]

Lot done today - amazing how fun in the shop on a cold rainy day can make the time fly!
Got the rest of the machining done on the boiler endplates - milled the holes in the front firebox plate for the firetubes (just like in the round endplate last post). Then mounted the throat plate back on the rotary table, using the holder that I had made to machine the throat forms. With the plate bolted onto the former (using the staybolt holes), first milled the curved throat surface to the right radius.

Then, moved the former and plate into the machine vise, squared it up to the table, and milled the side surfaces. These surfaces will mate with the boiler tubes and sideplates.

Last to get done were the firebox plates and the back plate, milling the side flange surfaces, using the same setups as milling the forms in the first place.

Last photo show the five plates all machined, and the staybolts test fitted to make sure all the holes still lined up (they did - phew!).

Next steps are to make a set of cross ribs for the backplate, will look just like the ribs on the front plate (shown in previous post). Then can make the firebox door tunnel - short tubular piece that will connect the firebox door openings in the firebox backplate and the larger backplate. That piece will be made from a strip of sheet copper rolled to size and soldered into a tube shape.
Couple more pieces, and can stand it up on the frame to see how it looks (remember the frame? Been off at the side collecting dust for a while! About to make the display base with a 3' length of curved track for it).

 

[Swifty]

Looking very nice, I'm still following with great interest.

Paul.

 

[Herbiev]

So am I. Looking great

 

[crueby]

Thanks for the interest guys!

Slight derail today - was soldering up the staybolts and fittings on the plates, but when I got to the large backplate could not heat it up quick enough to melt the solder before the flux was gone. So, went up and picked up a larger torch at the store. Hopefully it has enough oomph to do the job - amazing how quick copper wicks away heat. Hmmm, is oomph a technical term? Need 34% more kilaoomphs... Lets see, one candle is a millaoomph... :noidea:

Hope the new one can handle the larger assemblies. If not will have to invest in a larger hosed version - am currently using mapp gas handheld units. Will give it a try tomorrow.

 

[crueby]

Okay, got the new larger torch, that is working much better on the larger parts. Got the ribs and fittings soldered into the large backplate, and got going on the firebox tube. This tube connects the large holes in the backplate and the firebox plate, giving access to the firebox from inside the cab - it will get a hinged door later. To start, took a strip of copper, annealed it, and rolled it into a ring around a wood dowel (soft enough to do most of it by hand). Then ran a thin sawblade through the gap to get the angles of the ends to match up, and it was ready to rivit together. Made a little strip (same width as the gap between the plates will be), and turned a couple little rivits out of copper. First photo shows the first rivit hole drilled.

In the second photo, the first rivit has been headed over, and the tube is held in the vise and clamped for drilling the second hole - the vise is holding the ends together, and the clamp is holding the strip down.

With both rivits (rivets? however that is spelled....) in, the tube was ready to silver solder up.

Once that was done, I chucked it up in the four-jaw, centered it, and turned in the edges to match the holes in the plates. When the strip was rolled into the ring, the edges thicken up a little, so this step trued it all up for a good solder fit.

Fifth photo shows the plates test fit with each other, ready to solder the ring into the firebox plate.

Last two shots show the ring soldered up, and a final test fit with the backplate.



Last to do on the plates is to make and install the hinges for the firebox door. Then it will be time to make up the boiler tube sections.... So far it is going well, the copper is easier to work with than I had expected.

 

[bouch]

The boiler front end plate machining started with drilling holes for the firebox studs, the blower tube fitting, and starter holes for boring the firetub holes.
View attachment 72621
In the book, Kozo mounts the front plate (and later the firebox plates) to the lathe faceplate to cut the holes to size with a boring bit (drills this big would never give a clean round hole). However, this is another case where a little ingenuity was needed to do the operation on a small lathe. I could just get the front plate offset enough on the lathe, with the riser block in, but there is not enough clearance to do the same on the firebox plate. So, am doing those operations on the mill, which has a slightly longer reach, plus using the rotary table means the mill cutter only has to reach the inside edge of the hole, not the center. So, I screwed the plate to a piece of wood on the faceplate (same one used earlier to mill the formers), and milled the three firetube holes out to size.
View attachment 72622

Wondering if it would have made more sense to use a boring head instead of a rotary table and an endmill here...

 

[crueby]

Hi Bouch, I did some of the smaller bushing holes at the side with theboring head, but the head that sherline makes is a pain to adjust accurately and I gave up on it. One of these days I'm going to modify it to a better screw adjustment - they use a tiny adjust screw with a floating bar that moves when tightening it down. I've seen better designs on the forum that would work much better.

 

[crueby]

First part of the boiler shell is under way - started with a rectangular sheet of 2mm copper cut to the right dimensions, and the wooden trueing discs made earlier. Since I did not have a section of pipe about the right size or a rolling machine, I made up two more of the trueing discs to make a stack taller than the copper was wide, and clamped that in a bench vise. With the copper annealed, started forming it with a nylon hammer around the wood forms (did both ends first, then was able to push it around the middle section by hand).

Got most of the way formed before the copper work hardened (second photo).

After re-annealing it, was able to form it up the rest of the way (third photo).

Then, made a strip of copper to run down the inside of the joint and riveted it first to one side (4th pic)

then the other (5th pic).

At that point I soldered up the joint, and pickled/brushed it clean again. Now is when the trueing discs get their name - tapping them down the length of the pipe trued up the shape to a nice straight cylinder again (the soldering had the effect of annealing, so it would shape okay), as shown in the 6th photo. Note that I had to cut a slot in the edge of the disc to clear the joint strip/rivets.

After that, took a couple light passes on the mill to true up the edge (Kozo's measurements for the starting copper sheet take this step into account).

Last photo shows it with the hole for the steam dome and steam outlet fittings marked for cutting. Another nice trick Kozo did - has you scribe light lines in the copper when it is still flat and easily measured - that way laying out the fittings later is just a matter of measuring in from the end. The scribe lines dont show in the photos - I traced them in marker to make them stand out. Kozo cut the steam dome opening with a fret saw and filed it to shape - I am going to see if I can come up with a way to hold it in place to bore/mill it, not sure since it is such an odd shape to hold....

 

[crueby]

After a little hemming/hawing/dithering, decided to try the milling/rotary table approach on the steam dome opening - worked just fine - less chatter than with the boring head, which due to the way the boiler curves would have been an interrupted cut on every revolution. One thing I gotta say though - copper + sharp end mill + light finishing cut = some incredibly sharp and tiny little shavings, just the right size to stick themselves into the pores of your hand!!

Second/third photos show the steam dome bushing in place in the finished hole, a nice slide in fit.



After that, drilled and tapped the hole for the steam outlet fitting, which will be connected with a short length of bent tubing to the center hole of the steam dome bushing.

Fifth photo shows the two fittings set in place, before putting in the clamps on the steam dome.

Next photo shows one of the clamps in place before rounding off the upper surface - this is how it was left when making them earlier.

Seventh photo shows the two clamps after rounding off the upper surfaces on the disc sander, and the clamps bolted into place.

At this point, the two fittings are ready for soldering into place.

Time for a beer! (handy having a friend who runs a microbrewery - always something excellent tasting to celebrate with!) *beer*

 

[SilverSanJuan]

Take a look at this page: https://www.flickr.com/photos/90015082@N00/sets/72157608204743742/page3/

Scroll down a little and you'll see how Greg set up the boiler of his A3 to drill and bore the holes.

Keep up the great work, and thanks for all the photos!

Todd

PS. I posted this before I saw what you just posted above. Looks Great!

 

[crueby]

Take a look at this page: https://www.flickr.com/photos/90015082@N00/sets/72157608204743742/page3/

Scroll down a little and you'll see how Greg set up the boiler of his A3 to drill and bore the holes.

Keep up the great work, and thanks for all the photos!

Todd

PS. I posted this before I saw what you just posted above. Looks Great!

Todd, that is a great set of photos! Did he do a build thread for that engine? Different model but a lot of commonality between them. Thanks for the link.

 

[crueby]

I got asked where I bought the copper rivets for the boiler - since there are only a dozen or so needed I am making them by sawing off a square strip of copper sheet from the leftover pieces and chucking them up in the four jaw with enough hanging out for one rivet. Couple passes to tutn it round then parting it off. One instant rivet. Square head, but since that will be on inside does not matter. Made a bunch in a few minutes, quick shot with the torch to anneal them, and ready for use.

Last time I was building a lapstrake boat and needed them by the thousand, I bought copper nails and roves for riveting the planks. For this, no need to buy...

 

[crueby]

Fantastic fall weather out there today (high 70s, sunny, had to be outside before it snows by the weekend!), so only went into the shop for a few minutes - made the connector pipe from the steam dome fitting to the steam outlet. All ready to solder up. As I recall the only other thing left on this section of the boiler is to make another joint strip for the end of it.

 

[petertha]

I... One instant rivet. Square head, but since that will be on inside does not matter....

Sorry I'm not a boiler guy, what's the significance of square head? I just assumed they were always round for manufacturing reasons.

Also on most/all your copper machining, looks like dry for the most part vs. cutting fluid. Some rod I had was kind of sticky on the tool steel cutters & benefited by WD40 or tapping fluid used for aluminum. Who knows what alloy flavour it was though. Seems like you are having no issues?