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Einsy Rambo 12V fans

alvimalvim
in Motherboard
Is there a way to change the voltage for the fans on Einsy Rambo to 12V? I have 2 Noctua 12V fans that I would like to make them work.  

Comments

  • RepetierRepetier
    That is more a hardware thing I can not answer for sure. Guess it will always be the voltage you have on it.
    What you can do is just MAX_FAN_PWM

    /** Defines the max. fan speed for M106 controlled fans. Normally 255 to use full range, but for
    12V fans on 24V this might help preventing a defect. For all other fans there is a explicit maximum PWM value
    you can set, so this is not used for other fans! */
    #define MAX_FAN_PWM 255

    It will still be 24V but if you set it to 63 you get the same energy to the fan as with 12V full PWM over time. You then still use range 0 - 255 and internally it gets scaled down.
  • alvimalvim
    Hi Repetier,

    Thank you so much for your help.
    I have tried using M106 to move the fans but I still have to initiate the movement manually otherwise they don't work. I can still see them trying to move, but it looks like there is not enough power to start the spinning.
     
  • RepetierRepetier
    Do they run if you help them? That is a known problem and the reason we have a kickstart function to give them more power when you start from 0. It's defined here
    /** Some fans won't start for low values, but would run if started with higher power at the beginning.
    This defines the full power duration before returning to set value. Time is in milliseconds */
    #define FAN_KICKSTART_TIME 200
    /** Defines the max. fan speed for M106 controlled fans. Normally 255 to use full range, but for
    12V fans on 24V this might help preventing a defect. For all other fans there is a explicit maximum PWM value
    you can set, so this is not used for other fans! */
    #define MAX_FAN_PWM 255

    But in your case it will kickstart with reduced MAX_FAN_PWM so that might not work if 63 is not enough.

    Try adding
    #define COOLER_PWM_SPEED 2

    and see if that improves it. It reduces the on time in favour for more signals, but resulting in same average power. Might be that the fans like that more.
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