This is my version for a printout cooler for the K8200 or 3Drag.
For the hotend is quite rectangular, I dame it a square.
It's made for a 40mm fan.
I used the adapter to put a 70mm CPU fan to it.
The file "fan_mounts.scad" fives a frame and mounting holes for some regular fan sizes. Please divide the size by 10 (92mm size makes 9).
Edit: Added another lid for a bit more air flow to the printout.
I soldered the lid to the case by using an old soldering iron.
I found out, it's the best way to put PLA parts together.