Prusa MINI Z Brace

This is a Z-axis brace for the Prusa MINI.

It requires a new z-bottom with the front attachment point removed. The MINI-z-bottom part that I included is modified as needed, and it has a bit of extra clearance for the t-nut.

The brace is designed for button head M5 screws. I used 12mm screws for six of the eight attachment points and two 8mm screws for the ones underneath the y-axis extrusion, but 10mm screws would probably work for all. You'll also need the t-nuts.

This part really stiffens up the z-axis about x (pushing the top of z fore/aft) and about z (twisting z). It stiffens about y (pushing the top of z left/right) quite a bit, but I still wish it were stiffer in that direction. I may try tying the bottoms of the y-axis extrusions together.

You'll notice in the photo that I missed providing clearance for the y-axis bearing U-bolt. I updated the design with the needed clearance.

I included the Fusion 360 file for anyone who wants to improve upon the design.