[TR] Overdrive Update

[Randall]

> What did you use to machine it?

> What's it made of?

It's just mild steel, a scrap I happened to have on hand.  Shank to a broken
bit for the lathe as I recall; but the shank is not tool steel.  I was a
little worried about the soft steel holding threads (the screw is hardened),
but it worked out fine.

I happen to have a vertical mill, so that's what I used.  But it could be
done quickly enough, by holding the piece in a vise and grinding away the
unwanted parts with one of those cheap angle grinders from HF or whatever
you have on hand.  Even file it if that's all you've got.  (But I'd say the
angle grinder is worth the price even if this is all you'll do with it.)

-- Randall