There are already a few expansion card holders out there, but I wanted one with 16 slots in it, so I made one. You can print a top and bottom, or you can print 2 bottoms. It goes from 1 to 16 slots, and everything in-between. 3D printer required. You can download it here.
Mr moneybags with his 16 expansion cards over here XD
Nice job and nice silver filament.