Monoprice Select Mini M5 Lead Screw Mod

thingiverse

The original lead screw and stepper motor combo on the MPSM create rounding errors in height calculations and require odd layer heights. Any other lead screw with a nema 17 would have given even numbers. The M5 commonly used on the Prusa i3 gives even step values on any even number and fraction. Replacing the stepper requires drilling holes in the frame but wasn't that difficult. You can keep the old stepper and it will give you much better values on 0.1, 0.2 and 0.3 mm layer heights but it still won't be perfect. For this mod you will need to print the coupler and lead screw nut. I made the coupler using the customizer: Customized version of http://www.thingiverse.com/thing:1329750 Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=1329750 I didn't design the lead screw nut ,however I did change the name to reflect what we are using it for here. The holes line up perfectly with the original nut holder. The original design is by av8r1: http://www.thingiverse.com/thing:1959596 The lead screw is standard 5mm threaded rod, 0.8mm pitch.