Z Axis Break

This is a break that can be screwed to the Z Axis stepper motor so it stops the snagging of the gantry upon power off/power loss. 

The issue I had with Ender 3 is that when the stepper motors are disabled the gantry drops with a few millimeter and I was not able to recover the prints properly in case of power outage. I have tried to tighten the eccentric nuts but it required such tightness that had a negative effect on print quality (mostly very bad elephant foot and loss of z height). 

This is for 20mm diameter Z Axis coupler, but I uploaded the parametric Fusion file if that needs to be changed.

The strength of the break can be adjusted by the size/tightness of the rubber band.

Printing

Its an easy and quick print, I used TPU, a fairly hard one (95) so there is flexibility. With a not too strong rubber band it is does not hinder the movement of the Z Stepper Motor but does not allow the snagging of the gantry when Stepper Motor is disabled.