Building Kozo's New Shay locomotive

[crueby]

Got the truck support columns made - they bolt to the lower bolster, and guide the upper bolster on the springs. The angled slots in the upper bolster ride on tongues sticking out of the columns, which allow them to angle side to side and roll forward/back as needed on uneven track. These columns will also hold the upper framework for the rest of the truck structure.
To start, cut some slices off a piece of 1-1/8" square bar stock brass, and milled them down to the final dimensions (16mmx20mmx28mm).

Then, milled in the recess on the inside surface to make the guide tongue/base, a pair at a time.


On the outside surface, a recess was milled into the side

and the middle was milled to the same depth - this left a pair of columns sticking out.

After that, the holes in the top/bottom were drilled/tapped, and the outside face was angled back with a larger mill.

When assembled, the upper bolster is suspended on the main springs, and held from coming out by a small plate screwed to the top of the columns. The upper bolster has a pin in the center that holds it to the crossbar on the main frame, and also has a pair of blocks that ride on the crossbar.

The upper bolster is free to move up/down, tilt side to side, and roll forward/back a bit.

Next up is to make the webwork of flat bars for the rest of the truck, and then the really fun bit of milling, the journal blocks that hold the axle bearings. Those are complicated shapes, fortunately Kozo gives a good step by step sequence for milling them out....

 

[RonGinger]

Those are complicated shapes, fortunately Kozo gives a good step by step sequence for milling them out....

Kozo does a fantastic job of all his parts. I wish I wanted to build a locomotive so I could follow his plans. I have every one of his books, and have spent hours reading through them. There is a wealth of ideas in there for all manner of assembly and fabrication.

You are doing a great job, and I love all the photos. And all on Sherline machines was well.

 

[MatiR]

Hi Crueby:

Superb work, especially with Sherline equipment, which I have. I am an "off-and-on" model engine builder and post something here every year or two, some which has pushed the limits of Sherline stuff. Too lazy to add links, but Search should find them.

I bought the Kozo New Shay book, and the Climax book (which do I like best), a few years ago and thought that maybe Sherline could not handle it - you have proven me wrong. Your work might just get me going on this!

I have a Jan Ridders pressure-controlled 2-stroke engine 95% complete for about a year; got to get it done and get on with a locomotive, hopefully. I have been interested in narrow gauge, shortline locos all of my life; perhaps this will get me going.

Regards, Mati

 

[crueby]

Hi Mati/Ron,

The sherline machines are working out great for this project, nothing they cant do on it. I think it would have problems on a larger scale version, but the 3 1/2" guage works out fine. I got the lathe originally for doing parts for my ship models and little by little got drawn into the world of steam and added the mill to avoid all the wasted time switching the headstock. I love bothb building and learning new skills, on this one the silver soldering and sheet metal work was a nice step forward.

Chris

 

[Ed]

I'm kinda new at this, but I have a question. How do you know what gear cutter to get. I see there are a lot of gear cutters for sale. I would like to get a set of cutters that would do must of the gear gutting a hobbyist would do. Is there a set that would work and what would that set be? Thanks and I hope this question isn't too stupid. Ed

 

[crueby]

Hi Ed,

The gear cutters come in sets by "module" or "dp", which are two ways of expressing the same thing. Each cutter in the set will cut a gear with a given range of number of teeth in that module size - one cutter may do 10 to 15 teeth gears, next in set 16 to 24 teeth, and so on. Gears cut with cutters from the same module set will all mesh together properly regardless of how many teeth. Gears from different module sets will not.
So, the decision is what set to get. That will depend on what size teeth you need on gears for your projects. For what I have done so far, a set of 0.7 module cutters has worked out, have done several clocks and engines. A couple of the larger clock gears, at the weight end of the gear train, needed larger teeth for strength, so I hand ground the one cutter needed for that (being very slow speed motion the accuracy needed was not as tight as would be on a high speed engine).
If you are doing a large hit/miss engine you would need cutters for a larger tooth pattern. For watch gears, a much smaller tooth. Plans for an engine should specify the module or dp size of the gears needed.

Hope that helps.
Chris

 

[swst]

Great job! :bow:
I love watching your progress and your photo.Thm:
I feel very strange, all parts are made ​​with brass.
Why all parts to make with Brass.

 

[crueby]

Great job! :bow:
I love watching your progress and your photo.Thm:
I feel very strange, all parts are made ​​with brass.
Why all parts to make with Brass.

Thanks!

Most of the parts are c360 brass except for wheels/axles/drive shafts (steel) and boiler (copper) in Kozo's book, probably for ease of machining, maybe corrosion resistance, he does not give a reason. I have substituted steel for some parts like the long frame rails since steel was cheaper. Given the thick dimensions for so many parts of the original locos, brass works out plenty strong for the model. Lots less wear on my cutters too...!

 

[crueby]

The framework for the wheel trucks is done, ready for the journal boxes (which hold the axle bearings). The truck framework is made from 2mmX8mm brass bar, sawn down from sheet stock with a slitting saw.

Except for the diagonal bracing on the top all the bars are cut/drilled to the plans. The diagonal bracing is drilled one end, then marked for the other end - these bars have a slight bend to them so they can cross over each other.

Once the diagonal bars were all in place, they were trimmed to fit the outside corners. In the last photo, the wheel sets are propped in place as they will be in the final assembly. Still need to make the journal boxes to hold the wheel bearings - that looks to be a fun (complicated) set of steps....

 

[SilverSanJuan]

NICE! Look at all that beautiful brass. Great work!!

Todd

 

[crueby]

Got a start on the journal boxes. The left and right side boxes are different shapes, but they share a lot of positions for the mounting holes and the bearing cover plates, so I started all of them, then will do one side's boxes at a time when it comes to the detail shaping. The 4 boxes for each side were first milled to overall size,

then bored the holes for the line shafts in the right hand boxes,

and the mount holes/cover plate holes in all of them. This part went pretty quick, since once a hole was located in the first one (using the edge of the milling vise as a reference point) the table was locked down, and I could repeat the same hole in all 8 blocks. Tapping 32 holes 3-48 and 32 more as 2-56 took a bit longer....

The next steps are for the right hand journals only - these are recessed for the bearing block and also to clear the bevel gear on the right hand wheels. To start bored for the bearing block (this hole will be squared up in a later step to match the square-outside bearings),

then moved the 4-jaw chuck with the block still in place to the mill, and lowered the surface around the bearing 3mm, leaving the top edge for mounting to the truck.

Then recessed to leave a ring that fits into the center of the bevel gear,

and finally angled the area around the ring at the same angle as the bevel gears.

At that point, the other 3 right-hand blocks are next up to be milled through the same steps.

Next time will have the sides and back of the journal block shaped, and can start on the left-hand blocks....

 

[crueby]

Next step on the right side journal boxes was to mill out the bearing recess square (was bored to size on the lathe first for position and depth). The bearings are rounded on the top/bottom/back edges, so that it can tilt - the left side bearings are sprung to let the axles tilt independantly on rough track.


After that, the back side of the box was inlet at the bottom, and recessed up the middle. This recess will be redone once the back side is angled - this cut keeps the end of the recess square to the face.

At this point, all the other shaping/drilling is done, so it is time to cut the recesses down each side, leaving the 'feet' where the boxes attach to the rails. I did the main cut from the back, then had to finish it from the front since I dont have a mill that small with long enough flutes.

Last setup was to angle the box in the mill vise (used a wedge to get them all angled the same, was quicker than setting up the tilt table) and milling the angled area on the back face.


That finished the right side journals - was not as complicated as I was afraid it would be, Kozo gives a very good sequence for them.

Last photo is the journals test fit into the trucks - the left sides are propped up since the left journals are not done yet.... Looking very different as each piece goes on - cant wait to get the left journals made now!

 

[SilverSanJuan]

Fantastic work, crueby!

 

[crueby]

Cold couple days up here (wierd for mid-august, usually in the 90's now, been hanging around in the 50s and low 60s), so getting more done in the shop than usual.... Getting tired though, time to walk away for the day before I have a brain-fart and make a mistake!

Got the left side journal boxes done - started by milling out the rectangular center cavity, where the bearing slides up and down,

then milled out the recesses on the back side - one goes through, the other does not.

After that, angled off the back side just like the right side boxes, and

cut in the sides to leave the feet.


The completed boxes look simaler to the right side ones, except that the bearings are in a slot to move vertically. An adjustable-tension spring on top holds them down.

The screw sticking out the top is the adjuster for the spring tension. The spring tension on the center bolsters is not adjustable, just the one on the axle itself.

Last photo shows a test fit of the front truck on the frame - major milestone for this project, really looking like a loco now (can you hear the smile from there?? ). The gears mesh well, and the suspension works too. Still a bunch to do on the trucks - brake assemblies to make, and the gears need to be drilled/pinned in place on the line shafts, plus a coat of paint to put on the truck framework.

 

[crueby]

got more shots of the frame with both trucks on now. That brings it up to about 21 pounds so far - enough weight for it to turn the wheels/gears easily with a push to the frame.

Looking more like a train (or a government designed lazy-susan??)

 

[SilverSanJuan]

Time to get some rails.
Looks great!

 

[ddmckee54]

Have you started making engine noises yet? You probably will the first time you set it on the rails.

 

[crueby]

Have you started making engine noises yet? You probably will the first time you set it on the rails.

Dang! You saw me!!


I got some rail stock ordered. Also started milling out the brake shoes, though not as Kozo did it - he started with a large diameter brass disk, I started with some offcut blocks and shaped them on the rotary table - photos to come....

 

[Gonzo007]

Looks great. Keep the pictures and build log coming.

Colin

 

[canadianhorsepower]

very nice work , how long is this going to be ??
32 long but how hi and heavy??