3.5" Hard Drive Rail 12.5mm by 155mm

thingiverse

These rails will perfectly match the slide-in 3.5" racks commonly found in Centurion PC cases, and may also fit other manufacturers' designs. No additional hardware is needed; simply press-fit the pegs into the screw holes of standard 3.5" hard drives or 2.5"-to-3.5" adapter caddies, then slide them into the hard drive rack. To print these rails, orient one of the narrow sides to the bed and use support for the pegs during printing. Even if the pegs feel a bit rough after printing, they should still fit snugly into the drive mounting holes. When you're ready to remove them, using a flat-headed screwdriver will make it much easier to pop them off the drive.