Simple BTT Pi4b case

This is a simple screw together case for the BigTreeTech Pi4b adapter board.

No supports required, printed in PLA.

This is the same layout as the Raspberry PI 4 but without the hole for the audio socket.

I originally designed it to use M3 screws but then found out the the holes in the board were just too small to fit M3 so I redesigned it to use the screws that came with the BTT Pi4b adapter and CB1 cpu board with heatsink. There are small feet included that fit on the screws that hold the case together.