I designed this bracket to allow me to mount a 150mm x 86mm ATX PSU under a (Ikea Lack) table. It should work for a number of different configurations of ATX PSU, with mine having a 120mm fan on the bottom of the PSU.
Printed with supports in its current orientation but you could flip it and use less supports.
Print 2, i.e. 1 for each end of the PSU.
atxbracket.stl | 57.2KB |