Anyone ever swapped the brushes on their AC motor from the early Sherline mills? I've got a Spectralight 0200 that needs a swap on one of the brushes. My motor is the old AC type, made by Triem, with the following specs:
1/2 HP; 10,000 rpm; 115 V; 5.3A.

From what I can tell with my calipers, the brushes are 0.248"x0.248" and probably a little longer than 0.500". My searching has found the following brushes (only difference is in compound). Anyone have comments on whether these would work and which grade/compound would work? From best I can tell the resistance is fairly high, so my current plan is to go with the H25.

Brush Compound 1 (H3)
Brush Compound 2 (H25)
Grade Information

Thanks,
Joel