Unexpected fan behavior



  • I placed the following code into config.g:

    M106 P0 S1 F500
    M106 P1 S1 F500

    P0 is print cooling, P1 is heatsink cooling. Print cooling turns on when i power on the printer, but heatsink cooling does not. I physically swapped the cables and print cooling remains off, whereas heatsink cooling turns on. This would seem to indicate the fan pins at location P1 are damaged, except that the fan spins up for 2 seconds when the machine first turns on.

    What's going on here? I would expect the same result from the same command but that's not what I seem to be getting.

    Print cooling fan: Mechatronics 50x15 24v blower B5015E24B-BSR
    Heatsink fan: Mechatronics 40x10 24v axial MA4010H24B-RSR



  • @dc42 said in fans not working:

    To test a fan (fan 1 in this example):
    Send "M106 P1 H-1 S0". The fan should be off after sending this.
    Send "M106 P1 S1". This should turn the fan on.
    Send "M106 P1 S0.5". This should run the fan at a slower speed.
    To test fan 0 or fan 2, use P0 or P2 instead of P1 in the above commands.

    The results of these commands are as expected. Fan P1 stays off at S0, the fan turns on at S1, and the fan makes an obnoxious buzzing at S0.5 speed. Why though does fan P1 not start powered on when given the same config.g parameters as P0?



  • Seems that Fan1 (P1) is termostatically controlled by default. So you have to cancel this by M106 P1 H-1 to turn it on with S1. Or connect this fan to always on fan connector if you want it to be on with power on.


  • administrators

    @gibbeth said in Unexpected fan behavior:

    @dc42 said in fans not working:

    To test a fan (fan 1 in this example):
    Send "M106 P1 H-1 S0". The fan should be off after sending this.
    Send "M106 P1 S1". This should turn the fan on.
    Send "M106 P1 S0.5". This should run the fan at a slower speed.
    To test fan 0 or fan 2, use P0 or P2 instead of P1 in the above commands.

    The results of these commands are as expected. Fan P1 stays off at S0, the fan turns on at S1, and the fan makes an obnoxious buzzing at S0.5 speed. Why though does fan P1 not start powered on when given the same config.g parameters as P0?

    See https://duet3d.dozuki.com/Wiki/Connecting_and_configuring_fans.


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