On 21/01/17 18:53, Bob Engelhardt wrote:
I have a Jet 1024 lathe with a QC gear box. The box has a broken gear
that is really oddball in that its dimensions are inconsistent with
published standards. Such that I cannot find a replacement in any of
the usual places.

Anyhow, I intend to make a new gear on my horizontal mill and will
have to buy a gear cutter. That means that I need to know the
pressure angle. I found a website with a procedure to do that, but it
requires CAD and before I get into that, I'm trying here.
(http://mikesworkshop.weebly.com/chan...ure-angle.html)

Here is a photo of a couple of teeth on my gear and profiles of the
same DP from Boston Gear. The Boston Gear profiles are a different
diameter, so I can't compare by overlaying. I can't tell which angle
is closest to mine. Anybody know gears well enough to tell?

http://imgur.com/a/7O4O3

Thanks,
Bob

BTW - the lathe is from 1980 or so - if that helps.
There are some programs or javascripts on the net which will generate
gear profiles such as http://woodgears.ca/gear_cutting/template.html and
others so maybe try a few and print off the result to compare with. Have
you considered it may be a module gear size rather than DP.