Bench Tests: Commutator
- Clean surface and polish with No. 400 sandpaper if required. If surface is scored, out of round or pitted, turn commutator in a lathe to restore surface. Commutator runout must not exceed 0.016" (0.40 mm).
- Minimum diameter of commutator is 1.06" (27.0 mm). Mica depth on all models should be 0.016-0.031" (0.40-0.80 mm). The minimum mica depth is 0.008" (0.20 mm). If beyond minimum, undercut with a hacksaw blade to standard depth.