The magnetic force on the armature when it receives electricity wants to move it forward or backward within its magnetic shell. So that movement when the locomotive is to reverse jams it in your situation. A thrust washer might solve the problem. A minute movement of the worm on its motor shaft might solve it. Would need to be small movement.?
On Monday, January 27, 2020, 1:34 PM, Dave Smith via Groups.Io <SUNNYFIELD@...> wrote:
A bit off topic of group but it is model railroad related!
I wonder if someone you might have a suggestion for me about the following. I have an On30 Bachmann Porter engine that uses a worm gear to drive the axle gear. The locomotive runs fine in the forward position but stalls (jams) in reverse. I disconnected the running gear and wheels and it does the same. Motor spins internal gears in forward but jams in reverse. I removed the gear that sits between motor and axle and the motor and worm gear run fine.
Is there an adjustment that needs to be made to the positioning of the work gear? Some where I seem to remember that a thrust washer is used on the motor shaft containing a worm gear.
Any thoughts as to why it would run in one direction and jam in the other?
