Anet A6 Posi-Drive Leveling Upgrade

An Anet A6 printer uses a stepper motor on each Z axis screw. Both motors use microstepping to achieve small layer height. Problem is, microstepping was developed for smooth movement, not for accuracy. The two motors can not possibly remain in sync with each other. By the top of your print job, the extruder is no longer level with the bed. Over mulitple prints this accumulates to where the first layer no longer sticks to the bed on the high side.

The Posi-Drive Leveling Upgrade syncs the two