Armature

INSPECT
1. The armature.
A. If any of the solder joints between the armature windings and the commutator bars have come loose, replace the armature.
B. If the commutator is rough or damaged, replace the armature. Do not undercut spaces between bars in the commutator.
Clean
^ Dirty commutator with 400 grain polishing cloth and blow away all of the copper dust with compressed air.
2. Use a growler to check the armature for internal shorts.
3. Connect a self-powered test lamp between the commutator bars and the armature shaft. If the test lamp lights, replace the armature.
4. If the no-load test indicated that the armature may he rubbing against the inside of the frame and field, inspect the outside of the armature for signs of rubbing.
^ If scoring appears on one side of the armature. Replace the armature.
^ If scoring appears all around the armature laminations, check the frame and field for an out-of-position pole or for an object lodged inside the field. Repair or replace the field as needed.