Glenn Lyford wrote:
Hi all,

Not having immediate success (but by no means having tapped out
all available vendors or sources yet, either) I have not yet found
suitable gears to feed the quick change gear box on the Hendey.

I did in the course of poking through some of my boxes come
across a 3"OD x 6" long hunk of 6061-T6 aluminum (aluminium for
those across the pond).

I think this is your only mistake. Don't bother to make gears for
anything that is turned under power from aluminum. Gearing a
hand-operated knob that moves a valve will probably work with
aluminum gears, but the change gears in the lathe can transmit
considerable torque on coarse threads. If they don't break off,
they are going to wear really fast.

Jon