FOREDOM CARBON BRUSHES FOR SR PENDANT MOTOR

All Foredom Pendant Drills are 2-pole type and use a pair of brushes which need to be changed when they have been worn down to 6.35mm (1/4") long. Be sure to replace both brushes if one has worn down more than the other. The Brushes are intalled into the sides on the pendant drill one on each side at the opposite end of the flexishaft, they are installed in the brush holders that are made from copper or brass encased in plastic with shallow plastic screw caps which are to be removed to gain access to the brushes.

The leads from the pendant drill motor cord which are connected to the metal brush tubes, which the current flows into the brushes. The bushes are made from compressed graphite, they are carefully controlled characteristics to provide the lowest possible resitance, low fricition and long life.  

These brushes have a flexible copper pigtail is imbedded in the brush, the pigtail is surround by a coil spring. The free end has the correct curvature to match the commutator of the drill. When the brush is inserted into the pendant motor correctly it maintains proper brush pressure on the commutator and as the brush wears and the pigtail terminal contacts the inner metal tube to provide a current path to the brush.