Hi,
If the thread looks good then my guess would be that there is a gear ratio problem in the drive train somewhere. Is there a chance the manual or label on the machine is wrong? I had a problem with my 7x10 lathe where the gear selection chart in the manual was not correct.
You don't have to disengage the half nut for imperial threads. You could try leaving it locked, just as if you were doing metric threading and note the results. If there is no difference when using either method then I would double check the gear ratios. |