The crankshaft is the axle that connects the flywheel hub to the piston assembly. It is made of two parts: a rectangular aluminum piece and a rod of steel fitted together.
First, I cut the rod off on the cutoff saw. Since the rod was so small (and steel!), I decided to grind it down to size on the grinding wheel. I sized the rectangular piece similarly.
Next, I drilled and tapped the holes in the rectangular piece. There are 3 holes: one in the center, for the steel rod to fit into; one on the front but off center to allow for the up and down motion of the displacer to move the shaft; and one to add counterwieghts to the latter.
Finally, I fashioned a small aluminum round which fit into the displacer rod ring on the lathe and screwed everything together. The crankshaft was finished!
