Universal M-25 - Checking Gap between Shaft and Brush; Grounding Armature Coil; Diameters of Shaft and Bushing

Checking Commutator Wear
1. Check to see if the contact face of the brush is scored.
2. If scored, grind off with sand paper or on a lathe.
3. When the wear between the maximum and minimum diameters exceeds 0.4 mm,correct the
wear
to within 0.05 mm on the lathe. Allowable limit is not less than 2 mm smaller than the
reference
value of outside diameter.
Commutator diameter
Reference
value Allowable limit
28.0
mm 27.0 mm
1.1024 in.
1.0630 in.
161