I wanted a better way of fine tuning the Z end stop. Trying to undo a nut and adjust each time was unreliable for me.
I run the nut up onto the adjusting bolt to help stabilize the adjustment knob. By lifting it above the bearing mounting bracket, you can rotate and adjust the height of the bolt.
It's got 12 stops that fit loosely against this bearing housing. This gives 30 degree adjustments to the height.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/jgZUhLR9vSW
Printed mine with 0.2 mm resolution in ABS 220 degrees C, 25% infill on glass bed at 110 degrees C. My own preference is 4 layers before infill top and bottom.
Could easily be printing in PLA or other material, key is the side that touches the bed should be perfectly smooth and level to allow even adjustment.
It should fit somewhat loose to allow sliding up and down the bolt and nut.