I wanted to replace my RatRig V-minion stock 40mm controller fan for a quieter Noctua A6x25 60mm fan, so I went and modified the top panel for the stock electronics case.
Added a honeycomb grill.
Uploading the Fusion 360 file in case you want to modify anything.
I followed the wiring diagram in Nick Sherlock's post:
https://www.nicksherlock.com/2022/01/driving-a-4-pin-computer-pwm-fan-on-the-btt-octopus-using-klipper/
In a nutshell:
I'm replacing the stock controller fan, so I used:
[controller_fan controller_fan]
pin: !PD15
hardware_pwm: True
cycle_time: 0.00004 # 25 kHz
max_power: 1.0
fan_speed: 0.5
idle_speed: 0.5
shutdown_speed: 1.0
heater: heater_bed
kick_start_time: 2.0
tachometer_pin: ^PG11
tachometer_ppr: 2
The author remixed this model.