Pi 4 'Open Top' mount with 30mm fan

thingiverse

This pi4 box thing is obviously not going to win any beauty awards, but if you plan on parking your pi4 inside a dark junction box in some corner of a closet (alarm type installs), this Frankenstein of a box has some obvious benefits over the 'normal' looking pi boxes. With my pi3b's, I grew fond of UltiArjan's well-designed case. It is excellent for fanless setups, and I was using one without the top inside a junction box for my home auto setup. When upgrading my HA system to pi4, I wanted a similar physical design for the new hardware, so I hacked this together by remixing some parts from UltiArjan's original design, and I added some extra features to it for the pi4. The mount part is the same as the original, but with 'wings and holes' to make mounting much easier. The bottom part is just (rather unceremoniously) chopped here and there to make room for the different plugs on the pi4. The fan bracket is my design to fit a 30mm fan to the assembly. As shown in the second photo, the fan can be securely mounted with just one screw, which allows it to be rotated out of the way for easier pin and SD card access. I chose to set it at an angle to reduce boundary layer thickness and increase turbulence of the fan airflow (ie, for better cooling). Note if you do keep inside a j-box like I did, the jbox will still need to be ventilated! You can use a ventilated enclosure, or just drill a bunch of holes in a grey box. I did a combo of drilling holes and I added a small enclosure fan for the jbox as well (my box also contains backup batteries, chargers, power supplies, and some other Arduino stuffs). So a second fan was required to avoid heat build up, but may not be necessary depending on your exact environment and enclosure choices.