I using BLTouch sensor for compensation.
During the prints I found that the Z axis stepper looses some microsteps due to the bed compensating microsteps during the X-Y linear movements.
Due to this I designed this motor holder for my Ender-3, now I don't have step loss on Z axis.
As experienced the servo has usually 0,5˙ max position error, that means 0,011mm precision on Z axis.
It is also compatible with my BMG direct extruder design and later dual Z belt drive upgrade.
Minimal required parts:
2x - M5x20mm screew
2x - M5 slot nut
2x - washer for M3 screews
For fixing a motor I used two of it's own M3x40mm screws.
Some info about the closed loop stepper motor:
Sliced with Simplify3D
Horizontal size compensation: -0,15mm