Variable Enclosure Fans based on Temperature (no heater)

EducatingSavvas

Hiya - I'm trying to wire up a couple fans (intake and exhaust) into a CNC enclosure so they only turn on at particular internal temperature. They are a bit noisy so this is why I'm doing it.

I defined the thermistor with:

M308 S0 P"e0temp" Y"thermistor" A"Enlosure_Temp"
M950 F0 C"fan1+fan2"
M106 P0 T50 H0

Is this something possible to do without creating a heater. Plus is it possible to refer to the onboard CPU temperature?

Many thanks, Savvas

Argo

I would use daemon.g with that and conditional gcode. Already read through the Duet documentation about the topic?

jay_s_uk

@educatingsavvas you can only set one pin per M950 command

M308 S0 P"e0temp" Y"thermistor" A"Enlosure_Temp"
M950 F0 C"fan1"
M950 F1 C"fan2"
M106 P0 T50 H0
M106 P1 T50 H0

that should do, although don't forget to add the thermistor information to the M308 (at a minimum the T and B values)

EducatingSavvas

@argo it's been a little while since I played around with the conditional gcode but will give it a go when I next have time.

EducatingSavvas

@jay_s_uk I pulled out the thermistor from an old 3D printer so might not know the values for those. But will tinker on the weekend.

Phaedrux

@educatingsavvas said in Variable Enclosure Fans based on Temperature (no heater):

Plus is it possible to refer to the onboard CPU temperature?

Yes it is.

M308 S0 P"mcu-temp" Y"mcu-temp"

EducatingSavvas

@phaedrux

I can confirm this works. My fans are still noisy when they do turn on, but they are on for small amounts of time.

M308 S0 P"mcu-temp" Y"mcu-temp"
M950 F0 C"Fan1"		;Intake
M106 P0 T36 H0	;
M950 F1 C"Fan2"		;Exhaust
M106 P1 T36 H0	;

Many thanks, Savvas

Phaedrux

You might be able to experiment with the min/max speed settings as well as the PWM frequency to see if you can improve the sound.

https://duet3d.dozuki.com/Wiki/Gcode#Section_M106_Fan_On
https://duet3d.dozuki.com/Wiki/Gcode#Section_M950_Create_heater_fan_spindle_or_GPIO_servo_pin