A case i designed for my old Raspberry Pi 3B+ for use with Noctua NF-A4x20 for active cooling. As i use Raspberry for add blocking on my local network, sometimes CPU temperature got over 70 degrees Celsius, so i designed “simple” solution for it.

For PWM setup i used this guide: https://www.the-diy-life.com/connecting-a-pwm-fan-to-a-raspberry-pi/

Short threaded inserts for M2 screws: https://cnckitchen.store/products/gewindeeinsatz-threaded-insert-set-short-200-stk-pcs