Lead and cross slide screw precision?

[cdhknives]

Does anyone have hard data on the thread accuracy of the factory 'as shipped' lead screw and cross slide screws for a 10F?

I was talking to a career machinist friend who was replacing the leadscrew on his lathe and he was looking at precision ground stock... 0.001" class threads with very fine finish and he told me (he checked) the ACME screws from the likes of McMaster are 'merely' 0.006-0.009" accurate.

My lead screw was so badly worn when my grandfather got this lathe the edges of the threads @ the headstock were worn round. He had it flipped end for end and cut to fit, but I'm sure this end is also quite worn.

No I don't expect to do precision die work with this lathe, but if I'm going to replace it (I plan to sooner or later) I'd like to get it back to at least factory class accurate.

 

[pdentrem]

I had replaced mine with a new one from Clausings, I did not concern myself about the accuracy of the leadscrew. I did not ask at the time what it was.

The error of .006-009 per foot is not that large. Unless you are threading a very long shaft and a very long nut, the normal tolerances built into threads will be larger than the leadscrew error.

Now on the other hand, CNC is dependent on minimal errors for repeatablity. That is why they use ball screws and encoders etc.
Pierre

 

[cdhknives]

So no one here knows the tolerance/grade of the original lead screws on our Atlas lathes when they were manufactured?