Ted Sowirka posted:Some great work and useful information here! One more question about these switchers, if you still have it apart... what's the gear ratio? (How many turns of the armature does it take for one revolution of the wheels?) Also, are the gears "back-drivable," i.e., with the power off, can you turn the wheels and does the motor turn by doing so? Thanks again for sharing!!
Ted, the motor pinion has 9 teeth, the bull on the worm shaft has 19 teeth. That gives a ratio of 2.11 to 1. The worm is a 3 lead worm. The worm wheel has 21 teeth. That would give a gear ratio of 7 to 1. The overall ratio is 14.77 to1. So the armature would make about 15 turns to get the wheels to make one full revolution. With a three lead worm the wheels should be able to drive the worm, assuming proper lubrication. The additional spur gear set between the armature shaft and the worm shaft will make this a little more difficult. These 227 series locos run noticeable slower than most post war locomotives do.
