as most, received an athearn hi-f set about 1960 something. Later, my father updated the locomotive with a new motor/drive. The name Kemtron sticks in my mind. Anyhow… it is a large motor, with the magnet on top. There is a gear on the front of the armature, which engages a large nylon gear on a 1/8th inch shaft running thru the motor. You had to cut the towers off, and it uses o-rings instead of rubber bands. Made a pretty good runner out of the old Athearn drive. Anybody else heard of this?