Motor Brushes For Model Trains

June 10, 2014

Until the recent development of can motors, the electric motors in our locomotives had an open frame. In an open frame motor, all the internal parts are visible, the magnets, armature, and brushes.

Bushes come in pairs one plus +, and one minus -, depending on the chosen polarity, and rub on the commutator to transmit current to the armature, making the motor turn. Brushes are made of a carbon substance, quite small, usually round, and held in place by a light spring wire or leaf. As they wear the face of the brush takes the shape of the commutator. This wear sometimes causes the carbon to eventually fill the tiny grooves on the commutator, and require cleaning.