Now that I have a half-height rack and a 3D Printer, I figured I should finally move all my Raspberry Pis from sitting in odd places in my office to the rack. And what better way than to print my own 1U Raspberry Pi Rack mount unit?
The rack unit you see above was assembled from 6 'frames', 6 hot-swappable Pi carrier trays, 2 rack mount ears, and a couple lengths of threaded rod for rigidity.
It was printed from these plans from russross on Thingiverse; Russ Ross also made an assembly video, and shows how you can build a 2U 12-Pi enclosure using the same basic design, with interchangeable Pi trays!
There is more detail and a full walkthrough of my home rack in this video: