Taylor-Dunn B0-254-48 Operation, T Roubleshooting And Replacement Parts Manual page 109

Undercutting the commutator
1. Using a small straight cut saw blade, cut the
commutator insulation to the proper depth. Refer
to undercut depth in Service Limits.
2. Once all segments have been properly undercut,
mount the armature in a lathe and smooth the
commutator with fine emery cloth.
3. Inspect the armature for shorts. Refer to Motor
Inspection section for information on testing the
armature.
NOTE: Copper debris in the undercut area can
give a reading of a shorted armature.
Motor
Motor Service
Hacksaw blade
Incorrect Correct
Commutator
Example of freshly cut commutator
Page 9
Undercut
Armature
Insulation
Min. OD