Jon Elson wrote:

Bruno wrote:
A friend just got a Birmingham 12x36 lathe and tells me the leadscrew
is 8 TPI, yet the thread dial gear is 14 teeth, with 8 marks on it.
Anyone else out there with a similar lathe? Does it have the same
thread dial? I would think a 16 tooth thread dial would be
appropriate. What's the thinking behind 14, and will it really work?
Have him get a magnifier and count again. It is IMPOSSIBLE that
a lathe was built with a 14-T threading dial gear, unless the
guy who sold it to him is well known for practical jokes!

I'd expect if 2 teeth were missing, he'd clearly notice.

Jon
I asked him twice. He said he checked three times and always came up
14. He just got the lathe delivered yesterday and he's about 1500
miles from me, otherwise I'd run over and count myself.

I can't figure out how it would work, so I'm trying to figure out what
they were thinking when they made it. Perhaps they also made a 7 TPI
leadscrew ;-).

-Bruno