[Jim27]

Wanting to put a treadmill motor on an X2 spindle. Have the plans for the belt drive and can make the bore of the motor pulley whatever makes sense. Most treadmill motors have left hand thread which is the wrong way for the X2 as it needs to turn the direction that unscrews it. How is the pulley fastened to the shaft for this case? I suppose I could file a small flat on the shaft and use a setscrew. Could just use a setscrew but getting it apart again would be almost impossible if I ever needed to.

[shooter123456]

When I did it, I just cut the threads off and used a set screw. I never had any problems.

[maxspongebob]

Yes, grind a flat and use a setscrew. If you don't grind a flat, the setscrew will dimple the shaft and the pulley will not come off easily afterwards. The flat will also help the pulley from spinning if the setscrew is not tight enough.