I made a tool free caddy for 3.5 inch drives and a rack to mount all of them in a Corsair Carbide 100R pc case.

There is absolutely no extra space in the case with the cables attached, but it can be fit in there! It has a no-fastener slot to add a 120mm fan to keep the drives cool and air flowing in the front of the case.

This print has significant bridging and is almost the maximum size that fits on a Bambu 256mm bed. I used no supports and the draft (0.24mm layer height) preset with matte black PLA. It required some cleanup on the rack, but otherwise was ready to use as is.