Need Help!- Hardinge Conquest Twin Turn 65

[Jeff_Mezzo]

Been having troubles with the main spindle collets sticking when trying to feed material out to a stock stop. When you take the collet out there are burn marks on the angles portion of the collet. I clean the collet up and it works fine for about 10 minutes and it will start doing it again. I f you slap some grease in around the collet it might work good for a few hours tops. Anyone have any suggestions?

[g-codeguy]

Never heard of such a thing. Don't see how it could be possible unless the collet is turning separately from the spindle. This should be impossible because the spindle has a pin that must fit in the collet's keyway in order to be tightened. You must be missing the pin or it has been buggered up to the point it is no longer long enough to fit in the keyway.

EDIT: I assumed you were running 16C or 20C collets. Not familiar with that model. We are running 6 Hardinge barfeeds. Got the first one about 20 years ago. None are Twin spindles, tho. Did you order it with different collets? Or does it come with different collets than the two I mentioned? We have a Nakamura TW20 that uses B42 collets. There is no keyway on these. However, we have never experienced the problem you describe. No keyway sure makes it hard to automatically load a new bar of hex material.

[Jeff_Mezzo]

the burn marks dont appear to be from the collet spinning in the main spindle, looks like from colloet moving in and out. They key ways are in tact.

[duenow]

Originally Posted by Jeff_Mezzo the burn marks dont appear to be from the collet spinning in the main spindle, looks like from colloet moving in and out. They key ways are in tact.

Grind a small X over the burn marks with a thin cutoff wheel , then use lipstick. I've been doing this for 35 years for all my screw machines.