Getting the Pinion to stay on the motor shaft?

[brian015]

I guess the point some of us are trying to make is that pinions should not come off like this if they are properly tightened. The OP has already tried blue loctite with no success. It sure sounds like there's another problem and that simply getting the set screw tightened down on the shaft better is not the real solution. The misalignment of the gears appears to be the real problem.

Again, my experience with many different setups is that I've never needed to do anything special to keep a pinion on - except in the one case that I know my gears were misaligned - when I fixed my motor mount alignment, my pinion problem went away.