Remixed from nigeljohnson73's design here: https://www.thingiverse.com/thing:629886
Version 2 of my first RPi4 customizable / parametric fan mount. Fits any fan size up to 70mm. With customization, it can fit larger fans. Secure with M3 / M4 bolts (or whatever you customize it to be).
Customizer doesn't work with imported models, so use the openscad client to customize. Needs pi_front.stl in the same folder as pi_front_with_fan_v2.scad
Print pi_front_with_fan_v2_extended.stl and pi_back.stl in most cases.
If you wish to attach the two halves with M3 screws (I recommend nylon screws. Failing that, widen the 2.5mm diameter holes of the RPi to 3mm), then print pi_back_with_screw_holes.stl and pi_front_with_fan_v2_extended.stl