Controlling 2 fans with ramps 1.4 marlin ans motherboard 35

Hi, reprapers,
I Have 2 fans one for cooling down the hotend, and one to cool down the print whent printing overhang.
I configured marlin to set my ramps 1.4 as motherboard 35 which should allowed to control 2 fans.
One is plugged in d10, the other is plugged in d9, but when using M106 S255 command only the one plugged in d09 starts...
I guess there is a specific command for the one in d10 but with one???
Thanks for the help guys,
Victor

A hotend fan could just be connected to 12v (as you want it on all the time you're printing), but if you want to control it try M42

Yeah, but i would like to shutdown the hot end fan at the end of the print...even if the 12 is still on.I tried M42 which seems a nice option for me, but it doesnt do anything, the pin 10 i am trying to control stay at zero withs M42 P10 S255
Any ideas why?
thanks for your help anyway

I don't have Marlin available to check right now, but isn't motherboard 35 an extruder and 2 fans, so I assume it expects pin 10 to be the Extruder the same as motherboard 33, with fans on 8 & 9.

mother board 35 is extruder plus 2 fans, but the extruder is on pin 8, and 9 & 10 are for fans.

Quote
victorjung
Yeah, but i would like to shutdown the hot end fan at the end of the print...even if the 12 is still on.I tried M42 which seems a nice option for me, but it doesnt do anything, the pin 10 i am trying to control stay at zero withs M42 P10 S255
Any ideas why?
thanks for your help anyway

Don't do that. The hot end will still be hot and you don't want the heat to travel up the hot end. There's a slight risk the extra heat could damage a printed part further up, but the biggest risk is the heat will breach the heat break. If you're using PLA that will cause blockages.

This feature is built into Marlin already. You just need to set the extruder fan pin number, threshold temperature and PWM value (0-255). This way you don't have any GCODE modifications to turn on this fan. Uklan is correct, you don't want to shut off the fan immediately after a print stops. This feature allows your hot end to properly cool before turning off the fan to avoid heat creep.

See Configuration_adv.h. The example below will turn on the fan attached to Pin 9 (100%) when the hot end temperature is above 50C.

// Extruder cooling fans
// Configure fan pin outputs to automatically turn on/off when the associated
// extruder temperature is above/below EXTRUDER_AUTO_FAN_TEMPERATURE.
// Multiple extruders can be assigned to the same pin in which case
// the fan will turn on when any selected extruder is above the threshold.
#define EXTRUDER_0_AUTO_FAN_PIN 9
#define EXTRUDER_1_AUTO_FAN_PIN -1
#define EXTRUDER_2_AUTO_FAN_PIN -1
#define EXTRUDER_3_AUTO_FAN_PIN -1
#define EXTRUDER_AUTO_FAN_TEMPERATURE 50
#define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed

That's even more perfect! thank you so much salsabettis!

Hi, thanks Salsabettis I found this extremely helpful.