1

I know you can solder a mosfet and use the extra fan spot on a CTC Dual and control it with gcode. Can you control the case fan on the mightyboard with gcode in the same manner? If so how?

2

Do you mean the fan that blows across the stepper drivers?

that fan, although plugged in to a similar header to the “EXTRA” output, is actually connected directly across the power supply rails and as such is not controllable.

3

As slippyr4 said, that’s connected directly to power through the MightyBoard. Also, given that it’s cooling the stepper drivers, you probably don’t want to mess around with it, those drivers are passing a lot power through them for the size of the driver chips…so they really do need that cooling. (So, even if you did swap its connection to the ‘Extra’ output, it probably wouldn’t be the best idea to throttle down the active cooling for the stepper drivers, or the rest of the electronics for that matter.)