The Mark III is essentially a 3D-printed Raspberry Pi server rack, capable of housing up to 14 Raspberry Pis, each powered by the official Raspberry Pi power over ethernet (PoE) HAT, along with 14 2.5-inch SATA SSDs connected to the Raspberry Pis via a USB 3.0 to SATA adaptor.
The project began with a 3D-printable server rack model found on Thingiverse. Wanting to improve the design, Uptime Labs made some changes with the model. Multiple iterations were produced until arriving at the Mark III.
This unit can house even more Raspberry Pis than the original model and uses less filament to produce overall. This setup is huge but compact, requiring five 80mm fans mounted to the side for cooling.
Visit the Uptime Labs website for more details on how this project works or download the files and recreate it yourself. Be sure to check out our list of Best Raspberry Pi Projects for more cool creations from the maker community.