Here's a mount primarily designed for mounting an SSD in a tool less HDD caddy. It'll work fine with screws, you can just screw into the plastic, the tolerances are big enough for that. It will allow you to mount any 2.5" device to a 3.5" bay.
Lots of space around it for airflow and tapered fittings so nothing's loose or vibrates around.
Second picture just to illustrate the actual printed part.
Optimised for ABS.
Printed at 0.2mm layer height, I recommend using supports, they will be tiny and will snap straight off.