I needed to remove some ball bearings from an old power brush I'm
rebuilding. The outer race was hidden by the shoulder on the plate
it's mounted in, so I couldn't drift it out. I broke out the inner
race and tried grinding a notch in the outer race with a Foredom-type
grinder and a pink stone, which was taking forever.

I had some solid carbide end mills, so I mounted the plate in the mill
and used the mills to cut into the race. Pretty quickly found that,
even though the mill is fairly heavy, I had to lock the table down.
It's not really a great way to do it, though. The mill is a
horizontal, which means I'm working on the backside of the piece. And
I broke two endmills. Finally got through the race, but nicked the
housing a bit.

There must be a better way. Have been considering picking up some
carbide burrs for the grinder. Will these cut through hardened races
quickly? Any better choice of grinding points?

John Martin