The Home Machinist!

Looking good!

Hi Tristan,

I was looking at page 27 to get ideas for machining the large gears. One question I have is how did you turn the 4.000 countersink/lip without running into the heads of the clamp bolts? Thanks again.

-jlakes85

You're getting there Tristan, ahead of me anyway. I'm pressing the crankshaft together. Keys everywhere, light press and Loctite 648. I sure hope it lines up!

John, I bored the hole through the gear with the gear held on a fixture with bolts and then turned the lip by holding the gear through the center hole. I believe I used some spacers of soft metal between the jaws of the chuck and the gear so I could turn the whole of the lip, but I don’t remember for certain at this point

Sounds good. I eventually came to that conclusion as well unless you use an even bigger disk with tapped holes to toe clamp on the peripheral of the gear, which I definitely wasn't looking forward to

I remember what I did, it just came back to me.
What I did for the big gears was drill and counter bore the holes in the face of the gear with the mill, holding it by the factory hub. I then used screws to attach the gear to the fixture in the lathe and cut the factory hub off with a handheld band saw, was not fun but got the job done. From there, I turned the old hub off and bored the hole all the way through. Once it was to size, I turned the beginning of the recess from the bored hole out to the screws so it was the proper depth. From there I removed the gear from the fixture and then gripped the inside of the hole with the 4 jaw chuck and got it centered. Once it was set, I bored out the rest of the recess to the appropriate size.

Ditto for me. I just did 4 gears the same way Triston did them.

John B

Been a while since Ive posted an update here.... School kept me busy and Ive been running an experimental signal system at the railroad so both have cut into shay time, but things are moving a long.
First the brake cylinder has been finished and mounted. Its a little stiff on air but I think it will get better with use and on steam. The brake valve still needs to be made though. Next the boiler was pulled from the frame, cleaned, and then painting in VHT graphite engine enamel. Its a good looking color and I plan on putting it on the smokebox and stack as well. While the boiler was off, the front boiler supports got a coat of paint and then bolted down. And the king pins for the trucks were removed so the holes for some hitch pins could be drilled. Now the shay can be rerailed with a coupler crane. Around the time the boiler was going back on, the mailman brought some goodies. Two new standard injectors from Eccentric Engineer. They look sharp inside and out and cant wait to see how they work for me. I have one of the two pictured next to a SuperScale Economy and an Olhenkamp for comparison. Finally, tonight I got a fresh order of DOM tubing for the smoke stack and petticoats. The two petticoats were hot formed to get the flares. They still need to be cut to length and then a support frame built for them. The dimensions are from some computational fluid dynamics studies I did in Solidworks a while back and my data shows my design should be comparable if not slightly better than a Master Mechanics front end for the same size barrel. Hopefully this proves to be true. Only a couple things left to figure out for the smokebox before it can be finished. I need to figure out a blower setup, either a ring or a single piece of pipe, and how to get the line out of the side of the smokebox. And I also need to figure out how to attach the cast iron smoke stack ring to the steel pipe for the stack. Maybe careful brazing?

Soot n' Cinders wrote: ↑Sun May 20, 2018 11:00 pm I also need to figure out how to attach the cast iron smoke stack ring to the steel pipe for the stack. Maybe careful brazing?

If the ring has enough wall and thickness, and you'd like a nice, clean look that can be disassembled, you might consider drilling and tapping the ring, and using fasteners from inside the smoke box. Brazing, for me, would likely be a last resort kind of thing.

H

After much head scratching, I finally spent the day hogging off metal and machining the smokestack base. The radius isnt exact, but neither is the diameter of the smokebox. I scribed a line matching the radius of the smokebox on the side of the base casting where I'd get a 3/16" thick flange. Then I got out my 1/2" roughing mill and started carving out metal up to my line. From there I used an angle grinder and some sandpaper over the smokebox to finish out the radius. Then 6 mounting holes were drilled through the base and the smokebox and slid screws in. Now onto the frame for the petticoats and figuring out how to join the pipe for the smokestack to the mounting ring.

Im getting bad at remembering to update this... Too much time spent at work I guess lol.
Either way, the petticoats now have a frame and are bolted inside the smokebox. Put my PVC test stack on as well and ran some air through the engine and it seems to have plenty of draft, so hopefully she'll have no problem making steam. Last thing for the smoke box interior is figuring out how to do the blower ring and getting it through the shell.
Also have a sight glass on order from Locoparts and various fittings coming from PM Research so Im slowly working my way closer to lighting the first fire.

Looks very prototypical.
~RN