Z axis mod for Reprappro mendel mono or tricolour

thingiverse

This modification involves adding a second M5 nut at the motor end of the Z-axis to remove play in the thread. Begin by removing the Z-axis motor and unscrewing the threaded rod, then place the second nut in the nut case while leaving the spring in its original position. Clean the flange on the nut case and X-axis motor mount with acetone or MEK, then superglue the nut case in place. After the glue has set, transfer the spring to the slot in the nut case and screw the rod through both nuts, ensuring a small gap above the upper nut. Reassemble the Z-axis motor and realign the Z-axis. However, be cautious of issues with bed leveling caused by excessive pressure on the second nut or motor losing steps; consider using low viscosity lubricant, regularly cleaning screws and nuts, or adjusting X-axis belt tension for smooth operation.