Over the past few years, I have collected a number of raspberrypi computers. This growing collection has been hanging from a piece of particle board by network cables and power cables so it has looked very unorganized.
Recently, on Thingiverse I found a rackmount blade center for mounting multiple PIs.
It took about 35 hours total to print it out on the 3d printer at work but I was thrilled with the result.
cutting out the opening to mount the rack - the cut wasn't as even as I would have liked but I was in a hurry
the rack is screwed into place - all of the drawers have been removed
I love it!