fast89,
- Do scribe test's for reasons I mentioned. The scribe tests that i did were used to measure pitch to 0.0002" and
you don't get that from comparison to a tap. The tolerances are noted in threading on the lathe manual, page 26.
So for a 1/4-20 the error allowed for a 2A over .3" is 0.001". Said a different way.....one thread is 0.50", .3"/.050"=6 threads,
thus 0.001" allowed. If 0.0008" per thread you are over by .0008 x 6= .0048" - .001"=.0038 lets just say 4X.
- Although I have a C3 board for the index never put it into use. I think Russ has used it so he may comment on it.
- How linear and accurate is your Z axis?
RICH