I needed a pc case for a living room pc so i made my own pc frame design as most of the models here are for ITX motherboards. 

I made it the simplest with the least filament amount I could and in a way it fit on a standard 220 x 220 bed.

To build this PC frame you will need: 

-M3 threaded inserts

-16 M3x20 screws

-4 M3x10 screws 

-2 M3x30 screws for the PSU

-Motherboard Standoffs (3D printed spacers can do the job)

PETG filament would be safer for this print to resist temperatures but I printed it with standard PLA and had no issues.

EDIT: Added a revision of the two bottom side parts to allow better compatibility with more PSU. Also added more holes to the middle bar for the SSD bracket mounting.