I created a one-sided cooling for my Ender 3 with a 5015 fan, because I think this system is the best and is also used by a branded quality 3Dprinters.
Cooling is ready for mounting on a basic cooling box.
See the attached pictures for instructions on how to print and where to place your supports.
The fan 5015 is fixed by a screw to the nut, which is inserted from above into the prepared hole.
Enjoy cooling performance !
(my print - 0.14 layer hight - 0.4 nozzle)