by bill from nh » Fri Apr 12, 2019 8:46 pm
The 501 needs the crown gear to be on the right side of the pinion. The armatures in these 501 motors are timed 15-20 degrees. I assume the home track motor used the crown gear on the left side of the pinion. If so, when you reversed the polarity on the 501, you retarded its timing by some 15-20 degrees. The motor runs slower & hotter in a situation like that.
In addition to the 501 having a hotter armature than the home set motor, it has stronger magnets too, which should result in better braking. The 501 will also draw more power than the home set motors.