DC motors: "altered brush timings"
March 8, 2009
In this thread, under Chris' noise question, Cliff suggested that motors sometimes are optimized to run in one direction. To the detriment of the motor's performance when running in the opposite direction. Ken observed the same thing in car-window-wiper-motors. Now I want to know more about this.
Have a look at the motor I use for my Theo Jansen Leg experiments.
It is scavenged from a cordless power drill (about 18 years old). Notice the three slots in the metal case and the one (green) plastic tab in the plastic cover holding the brushes in place. The markings on the motor are mine.
Is this motor "optimized" for use as a power drill? Presumably, more power is required to run forwards (drilling, driving screws in) than backwards (occasionally unscrewing screws). Is this motor case prepared for three different commutator settings? Did I assume correctly when naming them "R"everse, "0" Neutral and "F"orward?