Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4625667.

My full size ATX motherboard mounting plate. It strictly follows official ATX specifications and fits nicely with my I/O shield. My preferred version houses 5mm brass bolts that accept screws rather than the version that takes standoffs. The original version included mounts for the ATX 2.2 Hole R and Hole S, but upon printing it, I found my Sabertooth board had heatsink screws underneath it that interfered with these and I had to break them off. This latest version therefore does away with those mounts in favour of screwholes for optional standoffs. Best of both worlds.