Hardinge Precision Tool Room Lathe

[pjs1inc]

Any of you guys had a problem with the collet not releasing the work piece?

I have to slam the arm 2 or 3 times before the collet releases.

TIA

[txcncman]

Yes. Happens all the time. Not just on Hardinge machines. Happens most when collets or spindle taper becomes worn and then you overtighten the collet to compensate.

[pjs1inc]

Yes. Happens all the time. Not just on Hardinge machines. Happens most when collets or spindle taper becomes worn and then you overtighten the collet to compensate.

Is there such a thing as an easy fix to the problem?

Thanks!

[underthetire]

Or the alignment pin gets messed up, or the grove for it in the collet. Too short of pin (worn) and the collet grabs it every time.

[txcncman]

You will have to trouble shoot the problem. Start by visually looking at the alignment pin inside the spindle. Is it missing? Bent? Worn? If the alignment pin seems ok, get a brand new, quality (not made in China) collet and a piece of bar stock and check if you still have the sticking problem. Crappy collets sometimes have the alignment groove cut undersize. See if the alignment pin leaves drag marks on the groove on the collet. Use the minimal amount of tightness of the collet to hold the material without slippage. If you still have a sticking problem, most likely the spindle taper will need to be reground. If the new collet and correct tightness solves your problem, then you know just getting all new quality collets and using the correct tightness will solve the problem.