On Fri, 2 Mar 2012 20:13:56 -0700, "Bob La Londe"
wrote:

The HF mini lathe hasn't been used since I got the slightly bigger much
older, and much better HF lathe. I wanted to use it the other day though
because it has gear selectable forward and reverse carriage feed. The I
remembered I stripped those little nylon gears. I am sure I can get a hold
of HF customer service and get a part number for those gears if its not in
my manual for the machine, but I was wondering if somebody knew of a source
for metal replacements? I know Little Machine Shop was the threading gear
set in metal, but I didn't see the rest of the gears for the machine.

My next thought was maybe to try and make some metal gears, but I have never
done that before. Any suggestions on the approach for that? Best alloy for
reasonable wear?







You'll need a dividing head, and involute gear cutter for the
diametrical pitch and pressure angle and the approximate number of
teeth in your gear. eBay is a good place to shop.

With these two tools, its a piece of cake, cut a tooth to depth,
rotate head, cut next tooth.

You might read "Gear and gear cutting" by Ivan Law to get a good grasp
of the subject. You'll need machinery handbook to calculate your
depths and blank and rotation values, etc.

To replace a plastic gear, I'd use AL. Otherwise, I've made gears out
of 4140 and then hardened. I've had one running in my backhoe for ten
years now.

This is a good basic skill to have. You're sure to be confused at
first, but then it will seem easy. Just like learning to ride a
bicycle.

Karl