Here's the 2.5 Inch HDD stand in 6 or 8 drive options.
There's honeycomb vents on the sides to keep temperatures down and to minimise print material while still maintaining good strength.
I printed it in PLA with 100% infill at a 0.3mm layer height on the Ender 3 without issue.
The drives are held in place with countersunk m3x5 screws.
I hope you find this useful.
Tips are welcome to keep the duck fed :-)