Temperature controlled fan on [fan0] stops



  • Hello-

    I'm using a Duet Wifi 1.02 on an ender5 printer with an e3d v6 hotend, firmware version is 3.01-beta1 (2020-01-14b3). I have three fans: one for the hotend and two part cooling fans.

    Initially I hooked up the hotend fan on fan0 and the two part cooling fans on fan1 and fan2. The config.g snippet for fan/tool setup:

    M950 F0 C"fan0" 25000
    M950 F1 C"fan1" Q25000
    M950 F2 C"fan2" Q25000
    M106 P0 C"fan_e0" S1 H1 T45           ; fan 0 - hotend cooling - H1 temp controlled
    M106 P1 C"fan_e1" S0 H-1              ; fan 1 - part cooling - controlled from gcode
    M106 P2 C"fan_e2" S0 H-1              ; fan 2 - part cooling - controlled from gcode
    
    M563 P0 D0 H1 F0:2                    ; tool 0
    

    When printing starts, the hotend fan stops. Prusa slicer puts an M107 at the head of the gcode, probably that's what kills it. The part cooling fans work as expected, controlled from gcode. I can restart the hotend fan with M106 P0 S255.

    However, when I hook up the hotend fan to fan1 and the part cooling fans to fan0 and fan2, everything works as expected (hotend fan turns on at 45C and stays on when printing starts):

    M950 F0 C"fan0" 25000
    M950 F1 C"fan1" Q25000
    M950 F2 C"fan2" Q25000
    M106 P0 C"fan_e0" S0 H-1              ; fan 0 - part cooling - controlled from gcode
    M106 P1 C"fan_e1" S1 H1 T45           ; fan 1 - hotend cooling - H1 temp controlled
    M106 P2 C"fan_e2" S0 H-1              ; fan 2 - part cooling - controlled from gcode
    
    M563 P0 D0 H1 F0:2                    ; tool 0
    

    Is there anything special about the fan1 port? Shouldn't fan0 also work as a temperature controlled port?

    Thanks-
    Lajos


  • Moderator

    @lajos said in Temperature controlled fan on [fan0] stops:

    M950 F0 C"fan0" 25000

    Perhaps the missing Q has something to do with it?



  • @Phaedrux Sorry, that was a copy/paste issue. There is a Q on the first M950 line (can't edit the original post). Looks like this:

    M950 F0 C"fan0" Q25000
    

  • administrators

    What's special is that M106/M107 commands with no P parameter (as commonly generated by slicers) are routed to fan 0 by default, unless you change that in your M563 commands. So it makes sense to use fan 0 for the print cooling fan, and fan 1 as the hot end fan.


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