On Oct 9, 10:36*am, Doug White wrote:
I am milling a part I want to fit reasonably closely to something (close
slip fit, ideally). *Something like -0.000"/+0.001". *I have it clamped in
my mill vise, and I have a stop set to locate one end. *I'm milling out a
small pocket, and the best I can do for measuring the width & length is a
digital caliper. *The thing it fits on is too big to try in place.

Thus far, I haven't taken it out of the mill. *I few more passes, and it
should be done. *My question is whether I have a prayer of taking it out &
returning it with adequate precision if it ends up a bit tight? *I was
figuring that if it doesn't quite fit, I could count on it not locating
exactly the same. *That way another pass with the same settings should open
it up a hair.

My experience says that I should (barring chips getting in the way) be able
to relocate the part within 0.001", but I'm not sure how much better than
that I can count on. *Depth isn't as critical, so a little "vice lift"
won't kill me.

Doug White

With power off, back off the cutter a little and advance it until it
barely pinches a strip of paper. After you check the fit you can see
if it still pinches at the same dial setting.

If you blacken the cut surface with a marker you can detect very light
contact with the spinning cutter.

jsw