Easy to attach and detach from 30x30 aluminum extrusion of the MINI's z axis, no screws are necessary!
Easy access to the Pi's SD card, no more disassembly required!
In case you are also using a PiCam module, a dedicated version featuring a hole for the flat cable is provided.
The Pi case is divided in two halfs to insert the Pi easily and match perfectly with each other: attached via zero-gap Snap-fit joints.

If you like this design, please consider buying me a coffee to support me in the creation of many other useful designs as a sign of gratitude for the huge amount of time and effort. Thank you very much and happy printing!

Updates

13/02/2022: Redisegned T-Slot-Clip so that the PTFE tube does not interfere with the cables on the side of the Raspberry Pi (see picture below).

Printing

Layer height: 0.2 mm;
Material: PETG (recommended), PLA;
Supports: Only for the MicroSD-cover overhangs;
Orientation: the models are already in the proper orientation.

In the Lower-case there's a 0.2 mm thick bridge to prevent the corners of SD card slot from falling making too difficult the insertion of the MicroSD-cover (see picture below). Once print finishes, just cut it out as if it were a support.

Assembly

Attach the T-Slot-clip to the alluminum extrusion;
Insert the Pi into the Lower-case and secure it with four M2.5x4 mm screws;
Slide the Upper-case into the T-slot-clip;
Take the Lower-case with your Pi attached and join it to the Upper-case by simply pressing them together;
Insert the MicroSD-cover into it's slot in the Lower-case;
Insert the Hexagon or Hexagon-hole into their slots on the Lower-case in wichever pattern you like (you might need to glue them to the Lower-case depending on your printer accuracy);
Now you're good to go ;-)