By grinding some with a little Proxxon ("Dremel but better") i could finally get the upper bearing off. But removing the bearing really took some force beyond normal. I was counting on that the housing would break and I'd have to get a new one.
The larger lower bearing came off without any problem. The upper one must have been heated and dropped in when mounted. Tolerances where not on my side here.
The notches cut in the rotor, on the left side of the picture, are to adjust weight during dynamic balancing of the rotor.
The brush contacts are hardly worn at all. the previous owner said it had been on a shelf for the last decade and not used much before that either. So swapping bearings should not have been needed, cleaning them would have been enough, but to do that, I still needed to remove them...
Last edited by janaf; 02-01-2012 at 02:11 PM.