Building Kozo's New Shay locomotive

[crueby]

Got the rest of the bushings done - first pic is the steam outlet fitting plus the water inlet and manifold bushings. Second pic is the collection of fiddly-bits so far (had to label them to keep track of which is which). Next can start on the steam dome base and the big collections of stay bolts.... Probably a couple days worth of those, lots to do. After that will come the wood forms for the sheet metal (then it can start looking like a boiler).

 

[SilverSanJuan]

Perfect idea for storing all those finished parts. And they look so pretty in there.

Todd

 

[crueby]

Got the steam dome base made - More to this one than just a cylinder so a few more pictures.
Started out with a bar of phosphor bronze, drilled the center hole (stepped hole to take the outlet pipe) and turned the rim down to size - stepped to fit in the hole in the boiler.

Parted off/cleaned up the part,

and put it on the rotary table in the mill to drill/tap the rest of the holes. The rotary table made it very easy to lay out the holes, which lie on two circles - just centered the table on the drill, and cranked it out the needed distances. Then drilled a hole, turned it 90 degrees, ready for next one.

Back on the lath, started the parts for the clamps that hold the base to the boiler shell for soldering. First, bored out the center to the same diameter as the small side of the base part, and parted it off.

That dish shape was then sawn into three pieces, the outer two are the needed parts.

They were then milled to width/length, and a hole drilled for the mounting screws.

The last two photos show the whole assembly. The clamps will be filed to an arced shape to fit the boiler shell later. Tightening down the bolts will draw up the base to the shell, and all the parts are soldered into place at that time.


That completes the boiler bushings. Next up are a whole lot of bronze staybolts....

 

[crueby]

First batch of boiler stay bolts are done. There are two type, first are a simple stud with a thread at one end for the front and back ends of the firebox (they get screwed into inner plate, soldered at threads, then other end is soldered into outer plate). The second style have a large head, and a flat nut.

The studs were turned to dimension in the lathe and threaded at the end with the die held with the tailstock, and then parted off.

The studs were then turned around, and the other end cleaned up and chamfered.

Third photo is all 11 studs done.

For the headed bolts, they are turned down to size and threaded, then parted off.

The nuts are drilled/tapped out of the leftovers, and parted off to size. The first edge of the nuts has a small chamfer, once all are made I will go back with a threaded holder and taper the outer edges of the nuts (does not effect function, just looks better).

First one down, just need to make 23 more of the headed bolts...

 

[SilverSanJuan]

I'll bet you're having too much fun.

Todd

 

[crueby]

I'll bet you're having too much fun.

Todd

Didn't think my grin reflected in the metal that well!

First 13 stay bolts done, 11 more to go... A return to warm weather for a couple days (30s yesterday, high 70s today) So I am headed outside!

 

[SilverSanJuan]

Enjoy that warm weather while you can. It is getting cold here.

Todd

 

[crueby]

Well, got through the big-pile-o-staybolts making, and have begun the wood formers for the boiler sheets. These will be used to hammer the copper sheets over to form the actual boiler parts (with lots of stops to re-anneal the copper again). The formers were laid out on the wood, and cut on the bandsaw slightly oversize, and will be machined down to final dimensions on the mill (a bandsaw is a very handy tool, but hardly a precision one). the blocks are from some Sapele offcuts from a display case/drawer unit I did two years ago (shows up in background of some of the engine progress photos now and then). It is a very hard, heavy wood, and very stable, should work well for the formers. I was a woodworker long before getting into machining metal, so this will be kind of a nice blend of the two arts...

 

[crueby]

Next step is done on the boiler former blocks - got them milled down to size. For the round ones, I screwed a sacrificial block to the faceplate, drilled for a bolt on the lathe to ensure the bolt was centered, and screwed that assembly onto my rotary table (which has a screw adapter for centering chucks on the table). Then I could bolt the round formers down and mill them to exact size (spiral mill leaves a finer cut on this wood than the lathe bit does, plus the odd shape ones later would not work on the lathe anyway).

Same was done for the smaller end formers.

For the formers around the firebox, which have a circular end and a straight base, did the same thing but stopped turning the table where it met the straight sections (third photo).

There are also a pair of formers for the forward end of the firebox area, which are just a rectangular section with an arc cut into the top. This needed a different holder, one with a tongue sticking out to bolt the former to (bolt holes needed to be right distance out to put the arc in correct place). I could not use a larger circle for this, since I dont have enough reach on the mill.

On the wider of the two, (fifth photo), there was not enough room to rotate it all the way past the cutter, so I did as much as I could on one side,

then finished it up on the other side of the column (did not move the former on its holder to ensure it stayed centered).

With both of the throat formers cut, bolting the together shows the step formed - the arcs are different by the thickness of the copper. This will allow using a pipe section to finish hammering down the flange there - will all become clear when that piece is made. Kozo really thought these formers through, looks like a good sequence he has in the book.

At this point all the formers are cut, milled to shape, and drilled where needed. Still need to go back and round over the corners of the edges the copper will be hammered over - will use a small 1/4 round bit in the trim router for that.

Once that step is done, will be time to start cutting copper sheet! Think I'm gonna cut each blank, and take some of the offcut scraps to experiment with the hammer (have wood and plastic head mallets for the forming)....

 

[petertha]

Cant wait to see this, I'm very interested in the process.

 

[crueby]

Cant wait to see this, I'm very interested in the process.

Me too! My first time doing sheet metal work, Kozo's instructions seem very complete so I am hoping it goes well. Otherwise I'll have some weird looking copper funnels and measuring cups!

 

[Swifty]

You have almost got me wanting to build a locomotive, I'm following along with great interest.

Paul.

 

[crueby]

You have almost got me wanting to build a locomotive, I'm following along with great interest.

Paul.

G'head, build one! You know you want to.... Your shop is calling out to you.... :hDe:

Great projects - when done, you can watch the engine run, plus the whole thing moves (they dont seem to be able to get away though, fortunately!). If you build one to large enough scale you can even ride the sucker!

 

[crueby]

Got the corners of the formers rounded over (1/16" radius bit in trim router), and also made the patterns for the endplates out of some card stock (wierd, a step that involves no swarf!).

Next step, trace them out on the 2mm copper sheet and start cutting...

 

[SilverSanJuan]

Beautiful! I did some reading on the wood you used. There were some comments about having some issues with tear out when machining it. Doesn't look like you had any trouble with that. They look great!

Todd

 

[crueby]

Beautiful! I did some reading on the wood you used. There were some comments about having some issues with tear out when machining it. Doesn't look like you had any trouble with that. They look great!

Todd

I've used Sepele on a couple furniture projects, even carved a rifle stock from it, never had any problems with the wood. Cuts like a figured Cherry wood. The grain is twisty compared to northern zone woods, which gives it a great ripply sheen, but is very stable, no warping. Like any dense wood, sharp tools are a must. It takes a varnish looking like a figured mahogany.

 

[crueby]

Wow - that worked out a lot easier than I had been expecting. Got the boiler endplates cut out

and formed. Annealed the copper with a torch and let it all cool down, then started in on the shaping. Using a plastic-headed hammer started hammering on the exposed flanges - got about 1/3 to 1/2 of the way over very quickly, then as the copper work-hardened it would get to a point were it would just bounce the hammer off.

Took all the parts to that stage.

I took that as a sign that it was work-hardening, and took it back out to reheat and cool down again (about 20 minutes or so to cool, its cold out today). After that, got most of the way over (all the way on the parts that were just straight sections).

Another re-anneal step, and the parts were formed all the way over.


The one that needed a fourth anneal was the throat plate, which has two side flanges going one way and the curved section going the other.

Once all the plates were formed, they were given a short soak in the Sparex acid pickle and wire-brushed under running water to clean them back up. Looking very good so far, ready to machine the edges to final dimension (which also gives a fairer surface for silver soldering).


There are still the tube sections and firebox to form, probably will do that after machining the endplates. They will be simpler bends, since they wont have flanges to deal with.

 

[petertha]

Very nice. Particularly the piece with flanges in reversed direction. So 2mm thick plate, that's 0.078" relative to 1/16" nose-over radius. I would have guessed that would be tight but it worked great!

- anything special about the copper composition itself? (this supplier shows C101 & C110 in plate. I wasn't even aware of so many grades)
http://www.onlinemetals.com/productguides/copperguide.cfm

- when you heat it, do you look for a specific discoloration or use a temp gauge of some sort?

- on the cool-down side, should this occur slowly, quickly, or doesn't matter?

 

[RonGinger]

Nice work, and as usual, very nice photos.

Copper is fun to hammer form like this. It does work harden quickly, and like you I have usually had to do 3 cycles of heating and hammering. You need to heat the copper till its red- low light level in the room helps for this. You can cool it quickly- Dump the parts in a bucket of cold water. that not only cools them very quickly so you can gt back to work, it knocks off most of the scale and the copper looks bright and shiny again.

 

[crueby]

It took a couple experiments to learn the right color to heat to. Was out in sunlight so was hard to see. No harm though, if I did not heat it enough it would not form much. Once I got the color figured out it went quick. I heayted and formed all the parts in batches, so only had to wait for cooling a few times for all of them.

In Kozos book he says to let it cool without quenching so that is how I did it. Not sure why he says not to quench. Possible distortion on larger parts maybe?? There are several things like that in his book that I'd like to ask him about. Not knowing, I took his word for it.

As I recall I had gotten the c110 grade from onlinemetals, waited for one of thier 25% off sales for it. The boiler sheets cut so far are about 8 pounds of copper, not counting all the bronze fittings or copper tube! Gonna be a heavy boiler.

Next up will be to start boring all the tube and bolt holes in the endplates, hose holes will give a way to hold it on the faceplate to mill the flange faces true.