Talking about extreme precision while the machine is not precise at all.
TrueUp Kit Version
Build in 'Cartesian Style Bots' published by Keith Davis, Aug 10, 2017.
A Cartesian printer using bushings for the Z axis instead of wheels or linear bearings. The design also synchronizes two Z axis screws with a timing belt for a level lift. The ratio of the drive pulley and Z axis pulleys produce .005 lift per full step on a 200 step motor, eliminating layer resolution "drift" caused by microstepping.