Raspberry Pi 4 breakout riser fan mount

Once again more of a build log than a printable. Of the cases I've used for Raspberry Pi 3 or 4, the iUniker is one of my favorites but doesn't give easy access to the GPIO headers. After making due with it for a while I decided it was time for a HAT style GPIO breakout board. I don't expect to need active cooling but wanted to keep it just in case. Luckily, I needed to raise the breakout board above the case for access to the terminals anyway and that gave barely enough space for a fan.

This setup creates about 24mm of space between the Pi and breakout. Fan placement is such that M3 hex nuts avoid typical heatsinks on the processor and RAM (14x14x7mm and 14x9x5mm respectively). For height clearance, a 30x30x7.5mm fan was used. Extra height could be cheated by using heat set inserts instead of hex nuts. This could either allow a 10mm tall fan or give more clearance below for heatsinks depending on if you put them in the fan or mount respectively.

I used a SMT short female header to tap off the fan power but I'm not sure this was the best choice. It probably would have been cleaner if I was tapping 3.3v instead of 5v on the other side but I wasn't really happy with the solder joints anyway. I think soldering directly to the base of the header pins would have given a more robust connection. There is almost 4mm of length at the base of the header pins to work with. Wire-wrapping would also be an option if you have the tools and want something easier to undo. Additionally, the short header setup forced the wiring go around the outside which made it tricky to close up the case without pinching the wires.

This setup was designed around this case and breakout board, but not specific to it. Because it sits within the Pi model B footprint it should work with any case with an open top. Other breakout boards or HATs with the same 8.5mm female header underneath will also work as long as no components protrude more than 2mm from the bottom.

Hardware as shown:

- iUniker Pi4 case [ amazon ]

- Freenove Pi breakout board (or similar) [ amazon ]

- Extra-long 2x20 stacking header [ adafruit ]

- SMT 2x20 short female header [ adafruit ]

- 30x30x7.5mm 5v fan [ amazon ]

- (4x) M2 x 10mm+3mm male-to-female standoff [ amazon ]

- (4x) M2 x 20mm button/socket cap screw

- (8x) M2 washers

- (4x) M3 x 12mm button/socket cap screw

- (4x) M3 hex nut

Assembly:

- trim case top cover holders off the upper half of the case.

- secure the Pi to the lower half of the case using the male end of the standoffs

- a M2 tap makes this much easier

- I used washers between the Pi board and standoff but don't believe they are necessary

- mount fan

- slip the fan wires through the cutout in the mount

- secure fan with screws and nut/inserts

- (optional) add 2-3mm of foam tape to the top lip of the divider to help keep the fan pulling air from the front edge and not warm air coming around the sides

- attach stacking header to the Pi

- wire fan power

- I've discussed my misgivings about the short header above but it works fine

- I used a tiny buck converter to give me some manual adjustment in the fan speed/noise

- set mount on top of standoffs and slip upper half over

- snap halves together

- attach breakout board onto exposed header and seat onto mount posts

- thread M2 screws down into the standoffs below and tighten to secure

- I used washers but I don't believe they are necessary

- depending on your print tolerances and how straight your standoffs went it you many need to work a bit to get things lined up