B9Creator Z Axis Motor Problems
1. Run Gold arm all the way up and down to feel for any catching.
2. Unscrew the gold arm from the back-lash nut.
3. Slide the gold arm up and down to feel for any catching.
4. If you feel any catching, look for burrs on the z-threads and/or the slide rail. Also try adding a small amount of lithium grease to the z-threads, and a small amount of 3-in-1 oil to the z-slide rail.