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?