I created this simple bracket in OnShape in order to mount my HyperCube's PSU (power supply unit) to the bottom of my frame (see attached pictures). It seems to function quite nicely and if you print it oriented the right way it holds up rather well, strength-wise at least...

To install this you'll need: (8x) M5x8 Bolts (for frame) (8x) M5 T-Slot Nuts (4x) M4x10 Bolts (for PSU)

NOTE: In the second photo, the PSU is zipped tied to the brackets; this is another way of attaching it if you don't have M4x10 screws (which I didn't when I first printed it!)

2017-11-26: UPDATED - Fixed extrusion mounting face thicknesses.