Alignment – the best way I’ve found to perfectly align belts is
- get motor mount (without motor) snug on hanger, then loosen a tiny bit so it moves
- install wheel and pulley with no speedring (washer) between the hanger and inner bearing.
- push motor mount flush up against wheel pulley so they are touching each other
- keep those held tightly together while you tighten motor mount clamps
- make sure mount is flush against, and touching, the wheel pulley, and there is no gap or misalignment
- finish tightening mount clamp all the way
- make sure again that mount is flush against, and touching, the wheel pulley, and there is no gap or misalignment
- when you’re all done, take the wheel and pulley back off, add a single 1mm speedring (washer) and just like that, the pulley will be perfectly aligned and 1mm away from the motor mount plate
- if you need it further away when you are doing tensioning, then add more washers
And also make sure your pulleys are concentric and don’t wobble at all