On Tue, 10 Apr 2012 14:12:11 -0400, "Wild_Bill"
wrote:

Roasting speeds are generally attained by using a worm gear reduction.

And as long as you're not delivering any serious torque, they're a lot
easier to make.on home-shop machine tools.

I've never made one that big, but I did make a couple of small sets
for my fishing-rod rotisseries, for distributing epoxy around guide
wraps. I cut the gears with ordinary thread taps in my SB 10L lathe,,
and the worm is just a threaded shaft.

--
Ed Huntress