Have a newer Afinibot but problem would be common to all similar designs. The 2 lead screws (some threaded rods) have aluminum couplers between the steppers and these rods that are used to alleviate Z axis wobble and misalignment of the drive screw etc. The design of these couplers make them like 2 large springs when the bed/Z height is set if you push on the X carriage you can see the coupler collapse and expand changing your gap adjustment and sometimes just leaving the paper under the nozzle the gap shrinks and paper shim would rip so you think lets adjust the bed lower ahh before you do it the gap opens up again shim slides way too easy so you think bed needs raising. You get everything approximately level then you make a final pass and level has all changed or changes while printing. Perhaps the only solution is a linear slide with two rods and zero backlash nut with steppers at 90 ' to the lead screw which is part of the linear slide. The backlash not really a problem since direction of Z is always up during printing 1 layer height each step. ? Anyone solved this problem 2? Anyone have a problem with linear slides 3? Should I bury the printer and convert to the planned linear slides belt x,y screw 2 Z's nema 17 or 23 all square aluminum tube frame and any extruder wanted ?/