Collet seat regrind?

So has anyone managed to diy a collet seat regrind? Or know someone in the EU who can do it for me?

So after measuring my new spindle (old one had more problems) I find that the runout is still in the 15μm range (0.0006") and I find that not awesome.

I’ve looked for someone who sells the “Straight Shank Chuck Holder” that is used in the spindle, with a specified runout but it all seems to be chinese “our-calipers-only-have-one-decimal” ebay quality.

And I don’t think its the 608 bearings since they are Japanese quality

There was a discussion of a jig for doing this on a Bosch Colt back when their collet problems first appeared — somewhere around:

Any decent machine shop ought to be able to do it though.

That runout seems a little more than we’d like — please contact us at and we’ll see what we can work out.

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