Limit Switch Holder for MPCNC

thingiverse

My MPCNC rails are a snug fit, measuring around 23.5mm in diameter, give or take 0.2mm. These tight tolerances make them a perfect match for the inserted square nut before the screw even reaches it. Upgrading to dual end-stop firmware on my MPCNC requires minimal modification - I wanted to avoid removing the bolts that hold the bearings in place and replace the roller plates without running additional wires through the gantry conduits. This would have necessitated changes to my wire management system, which I aimed to avoid. To print these parts, set your 3D printer to three perimeters with zero infill. Adjust the perimeter extrusion width to 0.45mm for optimal results. Layer height can be set as low as 0.2mm, although other settings should work just fine. Use five layers on top and four on the bottom - there are no overhangs that would require support. I printed these parts with eSun PLA+, which provides ample flexibility to ensure a smooth fit over the conduit. Regular PLA should also work well. When installing, insert the switch before tightening down the screw, ensuring it's seated correctly. The design relies on a single screw to apply pressure on both the switch housing and the rail, securing everything tightly when the screw is snug. When tightening, pinch the two ends together firmly to align the screw with the inserted square nut. I used M3x18 screws and flat square nuts, but this design can accommodate up to M3x20. The screw hole will also fit 6-32 machine screws, although matching nuts might not be necessary due to the ample material providing enough purchase for self-tapping.