Simplify 3d Cooling Fans Help

  • I have the duet 2 ethernet and would like to use the 3 Pwm fan outputs for different things. I would like to have fan 0 be a thermostatic controlled fan for my Hotend so that it turns on when its over a certain temperature. The problem comes with the part cooling fans. I would like to have two of them, one for each nozzle. I don't know how to set this up properly as simplify 3d doesn't seem to give many options for cooling fans.


    I have found the below lines of gcode that might relate to the topic, but Im unsure what to do with them and how to control them.

    {TOOL0REPLACE "M106 S0" "M106 S0 T0"} ; tool 0 uses fan 0
    {TOOL1REPLACE "M106 S0" "M106 S0 T2"} ; tool 1 uses fan 2

    I was thinking that it might be possible to simply put something in the layer change script that sets each fan through gcode on every layer change to accommodate a lower speed on lower layers, but I would also like the bridging fan speed override to work with both nozzles.

    Anything anybody knows on this would be invaluable to me!

    Thanks, Ethan

  • Hi Ethan,

    These are things that you would change in your Duet configuration, not in S3D.

    To have the hotend fan thermostatically controlled, this should be your config line for that fan.
    M106 P0 S0 I0 F4 H2 L1.0 T50
    Change H2 to your heater number, Set the T value to the temperature you want the fan to come on at. Set L to the fan speed you want. 1.0 is full speed.

    To use 2 fans (example fans 1 and 2) as part cooling fans you link them in your Tool Setup.
    M563 P0 D0 H2 F1:2 S"Extruder 1"
    The F value associates those fans with the part cooling fans for that tool.

  • Wow, thanks. I have a question though... Where would I put those in in the Duet Configuration and would things like bridging fan speed override still work for the nozzles?

  • You should have a Fans section in your current config file. In the Duet Web Control click on Settings, then on the System Editor tab and click on config.g to edit it.

    The Tool configuration should also be in there.

    The Bridging Fan Speed Override controls the part cooling fans and is used if you set your fans on the Cooling tab in S3D to something lower than what you want for bridging. So if you set your part cooling fans to 60% you can set the Bridging Fan Speed Override to 80% for example to get a little extra cooling during bridging.

  • Thanks for the help. So does that mean that the bridging fan speed override affects all fans and the fan speed also affects all fans? If so, when I set my Hotend fan to thermostatic control, will the S3D fan settings not affect that?

  • The thermostatically controlled fan will not change. It will be invisible and will just run any time the heater goes above the temperature you set.

    The Bridging Fan Speed and any settings in S3D will only affect the part cooling fans.

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