This is a REMIX from the brilliant Raspberry Pi B+ Shell Case by Beaubasaur - kudos!!! :D
The reason I remixed it is to make it compatible with the Raspberry Pi 3b and 4b which have 4x GPIO pins for the POE hat board at the ports side of the GPIO rail, which required the frame to be lifted higher to clear those pins.
I also wanted to make it easier and more ecological to print, so, I shaved the 3d logo off flat to the frame to be able to print easier without supports and made the frame itself 4mm thick which was substantially thinner the original.
The original author of the frame suggested using 1.75mm filament as pins to close the top and base together which I thought was an amazing idea, until it would not hold or line up correctly as the holes were a little too big - so, I added plastic locator pins to the top of the case legs so they can sink into the base without the need to add my own pins after printing.
Everything is remixed/designed with ease of print, the amount of plastic used and the time taken to print kept in mind.
Printed on a Flashforge Finder using PLA @ 0.24mm layer height, no supports, 210 C extruder temperature, 100% infill (for strength, as the frame/case is meant to stop things damaging the Pi)
Uses around 5.1 meters of PLA for a complete print weighing in at just over 15 grams and takes about 1hr 15mins from start to finish, depending on the printer used and print settings.
Case is compatible with all Raspberry Pi's that have the same motherboard mounting pattern, i.e. Raspberry Pi 2, Pi 3, Pi 3b+, Pi4b, etc.
May fit other SBC's with same motherboard mounting pattern.
EDIT : I have now added a riser that you can use to support your chosen HAT board, in my case a POE HAT board. Simply open the riser STL file, disable uniform scaling in the size settings and then set the Z axis to be whatever height you want (the distance between the Raspberry Pi and the HAT board when it is fitted to the GPIO) minus 4mm to allow for the height of the pin. The riser is 8mm and the pin is 4mm, so the total height of the riser is 12mm. The height of the top of the frame case with the logo is 12mm clearance from the Pi board which is more than enough to clear the GPIO pins without the need to print the risers. You may need two or four risers depending on your HAT board, which is why I published it as a single riser which you can copy and paste as many times as you like on the same build plate.
The frame is 4mm thick on both the top and base.
The pins are 4mm tall and 2mm thick on the top and the riser
The clearance between the Logo Top and the Raspberry Pi is 12mm without the riser
An excellent design by the original author, beautiful and eloquently engineered. If you need a quick case to get your bare Raspberry Pi off of your desk and allow absolute maximum airflow for overclocking, intense workloads, GPIO testing, etc. then this is the case for you!!!