Raspberry Pi 4 fan case (supports RTC)

I noticed that many of the current Raspberry Pi 4 fan cases placed the fan directly over the CPU. While that is nice in theory, it prevented having an RTC. This design tries to keep a low(ish) profile while allowing for a heatsink and DS3231 RTC spanning the first 5 header rows.

This is not a "snap" case. Since my primary purpose is for astrophotography, I wanted something that I didn't have to worry about popping open in the middle of an imaging session. I used M3x25 screws to secure the case together.

The fan is a Noctua 40mm (NF-A4-x10). It can be attached via screws or the vibration dampening pegs that come with it (just trim the ends). I cut the wires and placed new headers on for the 5V and ground lines. This worked reasonably well with my RTC which uses 3V.

By using a filament that changes color at different temperatures (Amolen tri color lava), I was able to optimize the placement of ventilation holes. This allowed me to drop the temperature a few degrees at idle and under a stress test. For my personal purposes, I don't intend to put that much load on it, but you can see in my images how the underside of the RPi 4 produces a lot of heat. Which means, you don't want to sit RPi cases flat down.

To that end, I made two different stands. One is more general purpose, to elevate the RPi. The other is made for telescope finderscope mounts. M4x0.70 flat head screws can be used to secure the stand to the case bottom before inserting the RPi. Or, you can use the Noctua vibration dampening pegs as legs hand have the case upside down.

The RPi fits snugly. You'll want to insert it at an angle, getting the A/V and power aligned before pushing the rest of the RPi into the bottom.

While I printed mine in the color changing PLA (for SCIENCE!), I'd recommend using something with higher thermal tolerance if you plan on running it hot.

Print instructions

Amolen Tri Color Changing PLA, 1.75mm (case)
Matterhackers Grey Build PLA, 1.75mm (stand)
0.15mm layer height to make the holes come out nicer