This power source box is suitable for inserting a printer into a custom made box.

I has been decided to use 100%fill because i need to drill holes for screws after print is made.

You can print a box in standing position without no supports. 

If you print a box lying, you will need supports, I recommend to use hexagonal support type.

You can use a box with reduced height and ignore top part thatis not printable with MK3S printer.