Gcode controlled fan

  • For some reason even if I set my cooling to 100% in the slicer, it only sets it to 95%

    Any idea how i can get it to respect the slicer setting?

  • Moderator

    Can you post your fan section from config.g?

  • Sure,

    ; Fans
    M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

  • From wiki: The F parameter sets the fan PWM frequency, in Hz. The default is F250, which works with most fans, Try F100 or lower if you find that you can't control the speed of your fan.

    So seems your fan doesnt like 500 Hz, try default (remove f parameter from M106 command ) or try lower value.

  • @falcar Can you get 100% using the sliders in DWC? Alternatively, what happens if you send M106 S255 via the console? If either of those give you 100%, then it's a slicer issue - most likely there is a max limit somewhere. You can test that theory by opening up the gcode file that you've set to use 100% fan speed in a text editor such as notepad++ and doing a search for "M106". You should see values of M106 255 but if they are around 242, then the slicer is capping the speed to 95%.

  • Yes i can move the slider to 100%

    I'm in the middle of a print right now, but i'll try that when its done.

    The main reason is the fan is quite a bit louder at 95% than 100%

  • you can change the pwm frequency while printing

  • I doubt very much that the PWM frequency is the OP's problem. It might affect the actual speed that the fan runs at, but AFAIK this isn't a tacho fan so DWC can only report the demand speed. The fact that DWC reports 100% when the slider is set to 100% indicates to me that the slicer must be setting the demand speed to 95% if that is what DWC shows.

    I'm assuming that the 95% values that the OP is reporting is what he is reading from the web interfaces or PanelDue, as I don't see how else he could know that it is running at 95%. So that would be the demand and not the actual speed and is therefore frequency agnostic as far as the displayed value is concerned.

    Or to put it another way, one could set the fan at 100%, then stick a pencil or ones' finger in it (not recommended) and the display would still show 100% even though the fan itself is stopped.

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