I had a different cooler before, but i liked the idea of completely enclosing the motor in this design better. And the idea of blowing some air into the extruder is really unique.
Without any cooling my extruder regularly hit the 50° and above (measured with an IR thermometer). The old cooler got it down to 36°, now it's running on a smooth 30°.
shouts to Kn4kworst for a really good design! <3