Thread dial issue

[bluearc]

The dial will engage with the lead screw and the lower gear of the thread dial will turn however, the top part with the numbers on it will not turn.
Will appreciate any help.

Thanks,
Bluearc

 

[SLK001]

There is a set screw on the gear. Tighten it.

 

[SLK001]

Here is the procedure for properly setting up a thread dial. Had to .ZIP up a .PDF, 'cause the PDF was too big.

View attachment thread_dial_10-16.zip

 

[hsracer201]

It isn't going to turn the top part while engaged...

That only turns till you lift the handle.

 

[SLK001]

It isn't going to turn the top part while engaged...

That only turns till you lift the handle.

The half nuts have to be engaged for the TD to "freeze" (stay in sync with the lead screw).

It would help if you told us what lathe you're talking about.

 

[bluearc]

There is a set screw on the gear. Tighten it.

Here is the lathe I am referring to;


SOUTHBEND 9X30
CATALOG# 415-AV
SERIAL # IS 85574

I believe it was mfg'd in the 30's

It will engage the lead screw ok but the numbers plate on top will not turn.

 

[hsracer201]

Can you clarify something for us? Take the thread dial off the lathe and while it is in your hand does the gear spin in sync with the dial? Can you make it slip?

 

[iwananew10K]

no power test(lathe OFF) half nuts open, apron in neutral-

does it turn when you crank the carriage back and forth via the apron hand wheel?

if so, exactly what racer said.

 

[SLK001]

Here is the lathe I am referring to;


SOUTHBEND 9X30
CATALOG# 415-AV
SERIAL # IS 85574

I believe it was mfg'd in the 30's

It will engage the lead screw ok but the numbers plate on top will not turn.

When meshed, if the half nuts are engaged, the numbers do NOT turn - that is what is supposed to happen. When the half nuts are disengaged, the numbers WILL turn.

I'm assuming that you don't have a QCGB and use gearing to change feeds and thread pitches and that the half nuts are used for both feeding and threading.