Radxa SATA HAT Case w/ 80mm fan

I wanted a case to hold my Radxa SATA HAT and drives securely and without just leaving them to get knocked over.  This is a quick and dirty answer to that.  It doesn't have an opening for the eSATA port, and the power ports could be a little cleaner, but it's nicely ventilated.  In heavy use with a 80mm fan pushing air into the case, the drives stay below 40C, and the Pi runs at 45C.

You will need M2.5 hardware to mount the Raspberry Pi to the base of the case and the brass standoffs that Radxa provides, and the top was designed to be attached with M3 hardware, but I suspect M2.5 would work as well if you have it.  The OpenSCAD design is included and uses parametric nuts and screw definitions, so it should be fairly flexible.  I ultimately used heat-set M3 nuts, but you could change the scad to use captive nuts instead.

I designed it to be 3 perimeters of a 0.4mm nozzle, but it should be parametric enough to be adjustable to your needs.  Despite the relatively low temperatures of the NAS, PLA will still get brittle over time.  PETG will hold up to the constant low heat application much better.

I printed some feet in TPU because I ran out of self-adhesive rubber feet, but either would work fine.

The current height of the top will accept a 20mm tall 80mm fan if you use standard fan screws from the outside.  There's very little clearance on the inside, if you were thinking about using machine screws & nuts, you should stick to 80mm tall fans, or edit the “CaseTopZ” parameter in the .scad and export a new STL.

A Noctua NF-A8 80mm 5v PWM fan does a good job of cooling without being too loud - at idle the drives are only 1-2C over ambient and the CPU is down at 35C.  The only time I hear the fan is when I'm rebuilding the ZFS modules and the CPU is running at 100% for a few minutes.  Otherwise it's below the noise threshold in my office.