Armature Test
- Using ohmmeter, check continuity between commutator and core. If continuity is present, replace armature. Check for continuity between commutator and shaft. If continuity is present, replace armature.
- Place armature on "V" blocks. Using a dial indicator, measure runout. Normal runout is .002" (.05 mm). Maximum runout is .016" (.4 mm). If runout is not within specification, grind or replace armature.
- Wipe commutator clean. Measure armature outer diameter. Grind limit is 1.22" (31 mm). If commutator is at, or less than, grind limit, replace armature. Check depth of mold between segments. Normal depth is .02-.03" (.5-.8 mm). Minimum depth is .008" (.2 mm). Replace armature if depth of mold is at, or less than, minimum.