MakerGear Forum

Hi:
Had my M2 for about a year and it's still prints great. I've had some issues which I've been able to work through, especially with the help of other forum members.
So here's my latest quest ... I would like to get more control of the speed of the 50mm fan. At the moment I have three options, 100, 99 and 98% (through S3D). Anything lower than that and the fan shuts off or doesn't start at all.
I know I read a post (a while back) that dealt with the firmware and certain "adjustments" that would enable a wider range of fan speeds. I've searched the forum without success. Does anyone remember the post or know of a post that might assist me in my search?

Thanks,

Mike H.

The fan control on the M2 uses PWM to regulate fan speed. The electronics and extruder fans are both PWM, and you can us M108 S0 through M108 S255 to set a value.

The cooling fan for your prints though...it doesn't use PWM, so its either on or off. M106 S0 or M106 S255

The main reason for this is the cooling fan is a single 24 V fan, where the Elec/Extrude Fan is 2 12V fans in series. To my knowledge there aren't any (many?) 24V fans that can use PWM, so you could try mimicking the elec/extrude fan and put two 12V pwm fans there, wired in series and then away you go.

Thanks jsc, Matt.

There was a post that referenced files on Github, and the (old) Makergear forum which detailed the process of altering the Marlin firmware, not only for fan control but for the addition of the "Viki" control. I'll keep looking.

Thanks

Mike H.

Try uncommenting //#define FAN_SOFT_PWM in Configuration.h. That may allow you to have more dynamic range on your fan settings. Depends on the fan, though. Fans generally don't like their power chopped up, which is why computer case fans have extra control wires to set their speed.

If that doesn't work, you can try adding a capacitor and resistor to form an RC low pass filter (https://en.wikipedia.org/wiki/Low-pass_filter#RC_filter) to convert the PWM square wave into something more resembling a steady voltage.

Thanks jsc. I'll try the first suggestion. The second is "above my pay grade" and better left to someone who won't set the house on fire

Mike H.