This is a USB Case that I designed specifically to hold 10 x SanDisk Cruzer CZ36. Of course, this may not be a perfect fit for your drives, so I have included a link to the OnShape models for anyone to copy and use at will. Sign up at OnShape.com - fantastic 3D modeling software, and free!
https://cad.onshape.com/documents/2aea3554550bab694129b55b/w/7b900a87fb43c4b512387a4f/e/cb26c09ced77ea259d1f3e90

Each half of the case prints easily without supports. Maybe throw a raft in there if you want a cleaner finish.

Post print: Drill out the holes in the hinges if you need to clean them up. Shove a metal rod through there- should be snug. Glue some magents into the 4 square holes if you wish.
Rods: http://tinyurl.com/3mmRod
Magnets: http://tinyurl.com/4mmCubeMagnet

Enjoy!