Hello All,
I finished up my first engine, a Duclos Fire Eater, some time back and have been waffling on the next. Finally decided on the Upshur Farm Engine - only one at a time!
Been very slow going as it seems no matter what stock I have it's always the wrong size, so been ticking along very slowly. Made some decent progress today.
First photo is the parts (actually, I should say the 'good parts' - I've made a lot of 'spares' or perhaps 'test' pieces) I've finished. The interesting piece is the Al bar with the two bronze rings - that is later cut apart and is the basis for the two flywheels.
This was made by cutting the Al bar a few thou (~0.003") larger than the ID of the tin-bronze ring, then the bronze ring was heated to ~200° while the Al bar was frozen to ~18° - the combination of the bronze expanding and the Al shrinking gave me about 0.0015" or perhaps a bit more to fit them together. One does not have a lot of time to make adjustments once they are joined as the temps start equilibrating and it shrunk very tightly together.
Next photos show the flywheels being cut out and some sizing before doing the web profile. (Before anyone says I shouldn't part with the a center in the workpiece, let me state I did not part them off with the live center in place - the second photo just shows how I cut out the 'extra' Al. The two were parted normally after getting most of the waste removed.
Last photos show closeups of the bi-metal flywheel, I'm very pleased with the way it's coming along and think this will add to the appearance. Now I've got to get cracking on the other bits and bobs.
All the best,
Mike