Raspberry Pi rack mount bracket for a Raspberry Pi 4 on a Monoprice 1u mount (x4) (Amazon: ) Works for Pi 4, but will be working on a Pi 3B soon. Fusion360 files included. Prints as two parts, a front piece and a bottom/base piece. No supports needed and optimized for 0.2mm layer height. I used two M4x12 to mount to 1u bracket (a M4x8 works but is a bit short). Then the PCB can be attached with M2.5 screws (or m2.5 standoffs if you mount a facover on the pi). pi-rack-bottom v2 has larger mounting points for the pi.