Klipper Guide:

Credit: https://ellis3dp.com/Print-Tuning-Guide/articles/useful_macros/hotend_fan_monitoring.html

Credit: https://www.klipper3d.org/Config_Reference.html#heater_fan


Requirements: 

  • Machine running klipper
  • Spare endstop port/pin (data pin, not GND/5v/3.3v), please refer to your toolhead board pinout.


Setup: 


Download Ellis Macro: https://github.com/AndrewEllis93/Print-Tuning-Guide/blob/main/macros/fan_tach_monitor.cfg

LDO Tacho Configuration: https://github.com/MotorDynamicsLab/Nitehawk-SB/blob/master/Firmware/Klipper%20Configs/tacho_macros.cfg


  1. Under your hotend fan, set "tachometer_pin" (Remember to set pull up to the pin "^" (example: tachometer_pin: ^P1.29 )
  2. Place fan_tach_monitor.cfg in the same directory as your printer.cfg.
  3. Add [include fan_tach_monitor.cfg] to your printer.cfg.
  4. Change min_rpm and max_consecutive_stops in the HOTEND_FAN_CHECK macro to your desired values. (The default value 3000 works well in our testing, you may want test yourself by stopping/slowing the hotend fan when hotend is heated up to pass your minimal toggle fan speed.)
  5. Place your desired hotend fan failure g-code in FAN_STOPPAGE_ROUTINE




Marlin Guide:


Requirements: 

  • Machine running Marlin
  • Spare endstop port/pin (data pin, not GND/5v/3.3v), please refer to your toolhead board pinout.


Within Configuration_adv.h (Find tachometers section)


Find and define E0 fan (in most case, hotend fan setup would be E0 (Extruder 0/1) with endstop/data pin. 


Example: 


#define E0_FAN_TACHO_PIN PIN19





RepRap Guide:


Requirements: 

  • Machine running RepRap 
  • Spare endstop port/pin (data pin, not GND/5v/3.3v), please refer to your toolhead board pinout or marked fan tacho port.



More Information: https://docs.duet3d.com/User_manual/Connecting_hardware/Fans_connecting


Example:

M950 F2 C"out4+out4.tach" ; Fan 2 uses out4, and using out4.tach as a tacho input