Raspberry Pi 4 Mini Desktop Case - Ice Tower Cooler + Secondary PCB Cooling Fan

thingiverse

8/21/2020 I made a version of this case that fits the GeeekWorm X872 m.2 NVME expansion board. https://www.thingiverse.com/thing:4576177 If you want to try out the secondary fans without printing a whole case: https://www.thingiverse.com/thing:4270044 5/4/2020 I added a revised structure part. Not a big change, I just increased the side of the hole the m2.5 screws go down into to accommodate larger screw heads. I had a builder tell me that the screws in his Ice Tower were too short to go through the structure part and the Ice Tower brackets and screw into the standoffs. So I got some longer (m2.5x6mm) screws from Fastenal and the heads were too big too go down the holes. So I made the holes bigger. I also added a hollow top panel (plank) that hopefully will print faster and better than the original solid version. And finally, I added a bottom plank which is also hollow, but also has screw holes under the recessed where the rubber feet pads are intended to go. These screw holes are the same dimension as the mounting screws on the Pi (49mm x 58mm). These are intended to accomodate rails for a 2.5" harddrive or SSD up to 9mm thick. The rails are at this link: https://www.thingiverse.com/thing:4333866 04/07/2020: I added three items that have 4040 in the name. These are a USB side with a funnel for a 40mm fan, a duct for a 40mm fan, and an HDMI side without the funnel for use with a 4020 (20mm thick) secondary fan. Some fans are a little thick to fit easily with the 40mm duct. Noctua 40mm fits nice, but they have rubber around the mounting surfaces. Cheap fans that are all plastic are tighter fit. Assembly of these parts - until I have time to fix the CAD - requires all the associates screws (that hold the duct to the structure, that hold the fan to the duct) should be left loose until they are all started. Worst case, you may need to file the screw holes where the duct screws to the structure to move the duct a half a mm towards the Ice Tower heat sink. Also, after extensive testing with multiple fans and several different configurations, I found no benefit to the Back Duct optional feature. So I deleted the update that even mentioned it, although the STLs are still there. --- More pics and writeup here: https://imgur.com/gallery/L55mBlI --- This is a case I designed for the Raspberry Pi 4 with the Ice Tower Cooler by 52Pi. I designed this during the coronavirus quarantine and in some ways influenced by this ongoing experience. For one, there's potentially hours of experimentation potential as there are different fan options to test... if you're stuck at home bored with nothing to and a spare Raspberry Pi and some fans sitting around. Furthermore, since supply shipments are sketchy, I kept the 3D printer filament usage to a minimum, thinned parts wherever possible, provided opportunities to fabricate some parts out of other household materials (like possibly cardboard for the top and bottom panels which are not structural and otherwise featureless). This case is intended to be used with the Ice Tower Cooler, but it adds a secondary fan above the USB ports. This secondary fan can be either 30mm x 7mm or 30mm x 10mm. There are both 5v and 3.3v fans in this size available and some fans claim to be capable of doing both. Giving the maker a whole lot of options to play with for hours of experimenting and charting temps. The second fan is mounted on a funnel which channels air down, around the USB ports and onto the PCB near the RAM chip. There is a grill around the SD card slot for exhausting heated air. Additionally there is an optional HDMI side panel cutout to make room for a 40mm x 20mm fan on the Ice Tower heatsink itself. There are also printable top and bottom panels (try printing them in vase mode to minimize material usage). The slots which hold these panels are about 4mm so they are big enough to hold a variety of materials such as cardboard, foamcore, wood, acrylic - whatever the maker has on hand to save precious filament. I try to avoid support material wherever I can. But the structure part will require support under much of it, the HDMI and the SD side will require a little support support around their ports/SD card socket recess. I recommend rotating the duct part 30 degrees counterclockwise and putting it's discharge port flat down on the bed. This will minimize support material requirement. You may need a raft depending on your bed adhesion as this part has little surface area to stick to the bed. Most of these parts are intended to be printed face down - the bottom layer becoming the outside face. Rotation will be needed for pretty much all parts - sorry about that. --- Hardware Required: 14 m3 x 6mm - 8mm screws. All exterior screw holes are countersunk, but pan head philips or allen cap screws will work fine. The fan duct screw holes are not countersunk, but countersunk screws will work fine. You will also need screws to hold the fan onto the duct. These 30mm fans seem to be all designed to use m2.5 screws. Who the heck has m2.5 screws on hand? Not my hardware store. So I designed the duct to use m2 screws to hold the fan on. 16mm long screws seem to work fine with both the 7mm and 10mm fans that I have. And you really only need two. Otherwise, all the hardware required is what came with the Ice Tower. The stock philips head m2.5 screws and standoffs and heat sink brackets are used to attach the structural component to the Pi board (see pics for proper orientation). --- In my own testing I have found the secondary fan to be worth 3-5 degrees (SOC temp) with my Pi 4 4gb overclocked to 2ghz with minimal difference (within the significant digits margin) between a name brand (Orion) 10mm thick fan and a (no name, cheap Amazon) 7mm thick fan. The difference was ~.3 degrees average over 25 fully stressed data points. But your experience may vary - that's hopefully some of the the fun of this. For a baseline temp with my pi 4 overclocked to 2ghz in this case I had an average temp under load of 40 degrees. With the secondary 30mm fan it averaged 35. Experimenting with a 40x20 fan on the heatsink and a 30 x 10 fan got temps down to 33 degrees. Youtube video showing this item in more detail including my thermal testing numbers in greater detail: https://youtu.be/PcIA3O3OnF8 Video details has links to fans used for the tests. --- 3/31/2020 I added three new files. BACKduct MINIpcUSBexhaustHOLE MINIpcSDduct These parts are to implement an option to have the air that passes over the PCB take a 180 degree turn after passing out the back of the case, and then travel back across the bottom of the PCB to be exhaust out the front panel below the USB ports. The drawback to this design is that the SD card is not as easily accessible. It will be inside the duct which reverses the flow back across the bottom of the PCB. To that end, this new duct is designed to be held on with two screws - the same screws as the back of the case - and a groove that clips on to the bottom of the opening in the back panel. https://imgur.com/a/jIEH4qw I don't know if this mod has any benefit. I haven't run my usual tests. But it's so easy to implement I figured I'd post it. My worry was that over cooling the top of the board but not cooling the bottom of the board could lead to the board warping, damaging the Pi. That's probably not a concern, but I thought I'd offer this change as an option anyway.