Am I able to modify this engine so I can lock the direction in which it travels? If so how?
Another way to modify your engine for one direction travel is a little more radical but it works great. You replace the circuit board with a 50 volt 6 amp bridge rectifier, most electronic stores have them to include Radio Shack. You lose direction control and even gain some power that way. Wire the motor leads to the plus + and minus - signs on the rectifier and the squiggly lines ~ to track power. DO not wire DC can motors straight to the track!