I wanted a modular rack mount case I could print on my smaller 3d printer. The choices I found on thingiverse was not exactly what i wanted, so I designed my own.

Fixed the chasis_blank.stl as it was not long enough for some reason

Creality

Ender 3

Doesn't Matter

Yes

.2

10-25

Please note that some parts are 206mm at their widest, so you will need a printer that can print at least 206mmx206mm. I printed it on an ender 3, which is 220x220 and it worked out well. I printed supports in certain spots and not in others. I had to do some finishing after printing, but it turned out pretty well. I used m3x8, m3x12 or #4/#5 self tapping flat head screws for screwing everything together. The holes for the raspberry pi mounting are smaller, m2.5 should work. I just used some screws i found laying around for mounting the pi. When everything is mounted and screwed together, it's pretty sturdy.

I used nothing but tinkercad to design this. I took measurements from online rack dimensions. I printed some test prints to make sure the interlocking worked like it should and then printed every part and assembled a complete 1u case. It fits nice and tight inside the rack like it should. The total height should be 44mm and it should just fit into a standard 19" rack. I have tested it and it fits into the racks i have available to me. I used multiple colors for printing, but I would guess that it would use about 1kg of filament to build one 1u case. Being that you can get filament for as low as $15 US, this is a pretty cheap enclosure.

This is the main brace to be used for the exterior walls. This is the green part in the tinkercad images.

This is a hollow interior brace so that you can pass wires or whatever between cavities. This is the yellow part in the tinkercad images.

These are chassis to be used to mount your electronics to. The blank one is one you can import into your favorite designer and change to suit what you want to put in the case. The rpi3 one is an example of a raspberry pi 3 mounted on the chassis. This is the orange (rpi3) and brown (blank) parts in the tinkercad images.

The rack ear is the side of the case to mount to the rack. The rack ear cover is the cover that mounts to the ear and the rest of the case. This is the purple (cover) and gray (ear) parts in the tinkercad images.

This is the main cover to be used on top or bottom of the case. The chassis and main cover are similar in that the chassis includes an exterior brace built into it and the main cover does not. This is the red part in the tinkercad images.