Re: [CAD_CAM_EDM_DRO] Stuck collet

yahoo@... wrote:

> What is the trick to getting the collet out of the spindle, when you
> are using a doubled-ended end-mill?
>
> If I hit the end of the mill, through the hollow spindle, I am going
> to break a perfectly good mill end.
>
> I also have had a hard time getting the bit out of the collet.

Depends on the type of machine, and the type of collet. But, I'm
assuming you have a collet with a threaded hole for a drawbar.
What you do is back the drawbar out about 3 turns of the thread,
and then tap the drawbar towards the collet. The threads prevent
the drawbar from going too deep into the collet and damaging the
tool. Depending on the taper, these can be from easy to massively
difficult to get loose. The shallow tapers like Morse and B&S
can bind up quite tightly. If you have a severe binding, you may
need to heat the machine spindle while icing the tool and collet.

But, usually, the drawbar will drive the collet free without much
trouble. You may be tightening the collet more than is needed.

Jon