So I wanted to add a 150w PSU, Raspberry Pi, a fan or two, and some other stuff to my Mini. Clearly this wouldn't all fit inside the bottom of this printer, so I decided to add more bottom to the printer! This adds 84mm of internal volume vertically and raises the entire printer about 95mm with the rubber feet I added.
Mean Well LRS-150-12 150W power supply
IEC320 power outlet/switch
Raspberry Pi 3
eBoot Mini MP1584EN buck converter (5v power for Pi)
Phobya 4-Pin to 6 x 3-Pin Fan Splitter
Noctua NF-A9 FLX 92mm fan
Scythe 100mmx12mm fan
Toowei T701A front side power switch
1/4"x11/16" rubber feet
Power/reset/LED PCB scavenged from old computer to control Pi
I'm including the design files in case anyone wants to modify to match their components. You may have to ream out the holes on the sides that connect to the pringer to match your holes, and using washers there is recommended. There is a ridge on the left side moduleon the front wall where the PSU will slot into, then you need to match drill a hole in the bottom to use the screw hole on the rear right screw hole for the PSU and secure it with a M3 screw. Rubber feet are sized for M4 screw/nuts, 92mm fan mount is sized for M4, all other hardware is sized for M3. There are some builtin supports for a couple of pins for the Pi and PSU that need to be clipped out. You need to remove approximately 1.5"x4" of the stock base on the left side to clear the 92mm fan, and rotate the printer motherboard 180 to connect the USB cable from the Pi through a hole you need to drill in the stock base to pass it through.
Be aware that the 92mm fan as designed might not clear the Z motor if you have swapped it with a Nema 17 motor
Use 3 shells and 50% infill for best results. PLA/PETG only due to warping