This is a case for a Raspberry Pi 4 with an optional mount for a Western Digital My Passport disk.
This is not really a remix, but I was inspired by https://www.thingiverse.com/thing:1815268. However I remodeled everything from scratch using FreeCAD (FreeCAD file included).
Some background: I used the original design (mentioned above) for a some time, but the small 30x30mm fans kept failing after a while. Also these small fans did not provide very good cooling. I got some Sunon 60x60mm fans for free from work. These have been installed in Barco F22 projectors, and are routinely being replaced at fixed maintenance intervals (around 10000 hours of operation if I remember correctly). The fans use MagLev bearings, and have plenty of life left in them after 10000 hours. The fans are designed for 12V operating voltage, but works fine even at 5V, and then only consumes about 35-40mA. They provide better cooling than the 30x30mm fans I have used, which consume close to 100mA at 5V.
I could not find any cases for these big fans, so I designed my own. I also designed an optional attached case for a Western Digital My Passport USB disk. I use 4TB and 5TB versions of the disks (nice for Nextcloud servers etc.). The Raspberry Pi 4 can boot directly from the USB disk - no need to have any SD card in the Pi.
The holes used for mounting the Pi are for M2.5 bolts. The three holes on the hard disk enclosure (for mounting the whole assembly on a wall or something) are 4mm. The rest of the holes are for M3 bolts.
The "Temperature.png" image shows a CPU temperature log from one of my Pis, running Home Assistant. On the evening of February 11th, there was a power outage. The 30x30mm fan did not start properly - probably worn out. Next morning I mounted this Pi in one of my new cases with a Sunon 60x60mm fan, and the CPU temperature dropped significantly (to about 35-37 degrees Celsius).
I got a request for adapting the design for Intenso harddisk. I added a parameterized generic HD, where the HD width and height can be set in a spreadsheet.
FreeCAD file have been updated, and cases for 11, 13, 17 and 20 mm Intenso disks have been added.