QU-BD Z rod coupling

thingiverse

The Z axis rod of my QU-BD Oneup kit had a drilled hole off center and misaligned with the rod, causing the extruder assembly to shift (not in the Z direction) as the rod spun. I suspect this would result in Z banding on the vertical sides of prints. Additionally, using lock tight to mount it to the motor was undesirable. Instead, I applied hot glue for a snug fit, which may not be necessary. A benefit is that if the Z axis is lowered too far, the coupling will force itself off the motor, preventing damage. I learned this the hard way. An added coupler has been provided for motors without a flat ground shaft, with a reduced diameter by 0.07mm; however, there's no guarantee it won't slip on the shaft.