Summary This is technically a remix of this design MP Select Z-Axis Bracket. by kingofl337. I redesigned it to accommodate shorter 12 mm socket head M3 screws for easier install. I also added a bit more tolerance to the fit of the back hex nuts. You'll need to print two setts of these for top and bottom of the rails. Print Settings Printer: MP Select Mini Rafts: Doesn't Matter Supports: No Resolution: 100 microns Infill: 40% Notes: I used higher amount of infill so the part would cut down on vibration. Post-Printing Installation These are pretty easy to install. once you have the two z-axis panels off. if you need help with that. Life and Times of Tyler makes some really great videos. I used some screws and nuts I got from Inventables.
M3 12mm length 0.5mm pitch Socket-head screws M3 0.5mm pitch nuts No washers needed
To make installing these easy I dropped the hex nuts in the back bracket part and put a piece of masking tape over them to temporally hold them in place I Installed the top bracket in place but loosely installed the bottom bracket in the middle then slid it down into place before tightening it.
Tighten each screw a bit then go back and tighten again until they are a bit hard turn.