Very simple bracket to stack two SSDs, or 2.5" HDDs on top of one another.

Meant for M3x8 screws, but M3x10 should also work. Spacing allows for an airgap and for SATA data and power cables to have plenty of clearance.

The total package is 17mm thick, nominally and PLA should be plenty fine for this.

Feel free to remix for 3 or 4 way stacks too, if you find you have the need and clearance in your  case or installation. Alternatively you can just use 2 brackers on opposing corners of one drive and then two brackets on the other two corners of the drive above to keep stacking them - though I wouldn't advise more than 3.