I recently ran into this problem and I’m not sure how to solve it. The auto Z axis on our machine has stopped working.
When I send it commands from Ground Control, the motor turns and the screw turns, so I believe the motor is working fine and the screw is attached well and properly. However the router does not move.
I did the anti-z-backlash adjustment with the washer and bushing recently, and tested it after that. All seemed well.
I suspect the tab is popping out of the router body. I colored with a black marker above and below the notch in the router body and it appears the tab moves below the notch without taking the router body with it, when I am giving it Z Lower commands. The spring for the clip/tab assembly is still in place and properly installed, the tab appears to function normally when I remove or install the router after bit changes.
I have also been playing with the clamp tension to try to fix this, both loosening and tightening but neither seems to work.
Any help or suggestions? Is nobody making a replacement tab for these things yet that actually works? Is the secret somehow more spring tension on the tab?