Re: [CAD_CAM_EDM_DRO] Re: collets

> To compare with commercial collets: I once bought a set of Lyndex collets
> for a cylindrical grinding fixture I was making.
> The difference in body diameter on these premium grade commercial collets
> was of the order of 0.0004", which meant that the smallest collets rattled
> in the bore that was a snug sliding fit on the biggest collets.
> I had to convince the people at Lyndex that their stuff was no good for my
> application, and even after "mix and match" sorting at the dealership where
> I got the collets, I still wasn't doing much better than 0.0003" TIR.
> Bored-in-place collets do better than that, almost without trying.
> The whole secret is to bore the collet in place on the spindle on which they
> will be run.

Indeed, I have often wondered about buying $6 import 5C's 1/64" under
the intended size and boring in my lathe. What is desired here is NOT
concentricity with the collet OD, but rather concentricity with the
spindle journals. I probably would try it if I had an ID grinder...

Chris