If you ever need to cluster up to 14 Raspberry Pis and an equal number of 2.5 inch hard drives, you might want to look at the Raspberry Pi Server Mark III case from [Ivan Kuleshov]. The original Mark I design came from Thingiverse, but the Mark III is a complete redesign.
The redesign allows for more boards along with a reduction in the number of parts. That takes less plastic and less time to print. The design is also modular, so there should be new components in the future.
In addition to the 3D printed parts and the electronics, you also need five fans and some miscellaneous hardware and cables. The setup is made to accommodate a power over Ethernet HAT, but apparently you can also get it to work without it. You also need a power supply for the fans, so we aren’t sure the Ethernet power matters that much. We have to wonder what [Ivan]’s up to with all these computers and hard drives in a rack mount.
The 10 STL files and some other data is in one downloadable ZIP file. Of course, some of these you print multiple times, so expect to keep your printer busy for awhile.