Yes, the copper segments do wear down over time, and particularly for a motor
under heavy loads like a windlass
. However, they can only wear down to the level of the insulator before they stop working. You can get many more years of service
from it by carefully filing the insulators back down below the contact segments. Usually, a hacksaw blade fits in there perfectly. If not, then look for some micro-files or coping blade or thinner jigsaw blades.