You can also just make up a temporary "lathe" for something like that. A couple of pillow blocks for an arbor, etc.
I've done stuff like this for wood but how would you go about the toolrest for metal?
Steve, two possibilities.
1.) A simple woodturning style tool rest and a hand graver -- this is how the original metal lathes worked, and for something like a flywheel, I think it would be quite workable -- particularly for aluminum, which I'm guessing would be cast for this engine.
2.) I could easily temporarily remove the cross slide from my Gingery lathe and run it onto a bar of cold rolled steel as ways -- since that's what the ways are composed of in the first place.
It may be possible to do the same thing by removing the cross slide from another type lathe fastening it down on the temporary setup, and just using the top slide for motion. The range of motion needed to finish the rim of a flywheel is quite small, and this is a one time job, equivalent to faceplate work, so a little ingenuity would see it accomplished with minimal materials, I think.
Probably my first choice would be # 1 above, as a flywheel rim isn't required to fit anything, but must only be made concentric to the bore and smooth.
