For the HercuLien, do you guys wire the two fans on the hotend always

For the HercuLien, do you guys wire the two fans on the hotend always on,
[ just to the power supply], or do you connect them to the control board so you can turn them off and on? And if connected to the control board, are they together or on separate control pins? I can do either with the Smoothieboard, just wondering what the prevailing opinion is.

I wire mine so they turn on and off at 50C

I have mine directly to PSU but burn out fans quicker. How do you set up that wiring @Eclsnowman

I use the same strategy as @Eclsnowman on my Herculien. The relevant lines from my config file are below.

automatically toggle a switch at a specified temperature. Different ones of these may be defined to monitor different temperatures and switch different swithxes

useful to turn on a fan or water pump to cool the hotend

temperatureswitch.hotend.enable true #
temperatureswitch.hotend.designator T # first character of the temperature control designator to use as the temperature sensor to monitor
temperatureswitch.hotend.switch fan2 # select which switch to use, matches the name of the defined switch
temperatureswitch.hotend.threshold_temp 50.0 # temperature to turn on (if rising) or off the switch
temperatureswitch.hotend.heatup_poll 4 # poll heatup at 15 sec intervals
temperatureswitch.hotend.cooldown_poll 60 # poll cooldown at 60 sec intervals

#configuration for switch controlling fan on E3D hotend
switch.fan2.input_on_command M42 # gcode to turn on
switch.fan2.input_off_command M43 # gcode to turn off
switch.fan2.enable true
switch.fan2.output_pin 2.6 # pin that controls the fan on E3D
switch.fan2.output_type digital # on/off control (no pwm)

@Zane_Baird What controller are you using?

i wire mine to 24v as i cant get my azteeg board to turn them on at the ports described in the instructions

@Bruce_Lunde I’m using a smoothieboard on my herculien. I don’t think it’s accurate after my rebuild, but here is a picture of my wiring ( with a description (

I definitely have it slightly different now, but it only means you have to change the pin numbers.

Thanks for sharing that @Zane_Baird

@Bruce_Lunde No problem. If you have problems or questions just let me know. I can also share my config file for that setup if you need it, but I suggest you work that out for your particular setup so you know how changes will affect it.

Thermostat fan control is so easy that I don’t see why not use it unless you’re out of FETs. Yes, ideally the machine should be printing whenever it’s on, but no need to make a racket when it’s not.

I’m of the other opinion. Ingentilire is on 24x7, ready…waiting…but only turns the e3d fans and board cooling fan when th extruder crests 50c, like @Eclsnowman

I have just gone through so many hot end fans. It’s a difficult job those heat sink fans serve. Hot location, and lots of acceleration forces acting on the bearing (or in most cases bushings). If I can save some life on the fan by turning it off when not needed… Count me in :slight_smile:

For awhile I used a 4020 blower to cool my hotends… That was only because I was waiting on 24V 30mm fans. I will get on board with the next controller that give me a variable voltage selection on a switching PS for fan outputs only. That way I can source the fans a little easier

@Derek_Schuetz ​ I wire mine as shown (open in acrobat to see my sticky notes in the PDF). Then there are a few items in Marlin to config… But I am on my phone in a hotel. So I will have to look later. Just need to make sure pins.h is setup with those outputs as the heatsink fan output. And then define the turn on temp in config.h I think.

I followed Eric’s settings at a specified temp to turn on the hot end fan automatically. Works great on my Azteeg X3. I rarely use the bed fan since I mainly print ABS but can turn that on when creating a print file from Cura. The hardest part of all this is setting is the firmware and finding what pin to use for a specific controller board.