Anycubic i3 mega extruder stepper fan holder aiming at filament (with or without ON/OFF switch)

Following several broken PLA filament due to excessive temperature (for the filament) at the extruder stepper level, I designed a holder for a Noctua NF-A4x10 FLX fan in order to have it blowing air directly at the filament. The filament stays cool and I have never had any broken filament after that !

I added a place to put an ON/OFF switch if you do not want to have the fan spinning all the time when the printer in ON.

Can be used when a filament gear knob (https://www.thingiverse.com/thi