Multiple Part Cooling Fans (M106/M107 controlled)

General Discussion
1

I have been running Klipper with a toolhead that has two part cooling fans that both run off of the same signal. Therefore, when an M106 command is run, they both operate in parallel. I am experimenting with a new tool head that requires each part cooling fan (there are 2) to be controlled independently. I have the second part cooling fan controlled using a [fan_generic] section and I am able to manually control it using SET_FAN_SPEED command.

[fan_generic extruder1_partfan]
#controls right extruder part cooling fan
pin: PC23

SET_FAN_SPEED FAN=extruder1_partfan SPEED=0.5

The problem is that extruder1_partfan doesnt respond to the M106/M107 commands which makes me question if I am doing this properly. Is it only the fan defined under the [fan] section that responds to M106/M107 commands? My thought was to redefine the M106/M107 commands with gcode macros that call SET_FAN_SPEED to control the other fan, but I am hoping there is a better option.

Am I way off here? Appreciate the thoughts!

Thanks

2

See

and

3

Finally able to get back to this. I ended up just using the [multi_pin] feature to alias both part cooling fan pins in the [fan] section since both fans are on the same tool head. This worked as expected. One thing to note (that should probably be put in the documentation) is that the [multi_pin] section needs to be defined before the [fan] section. This may seem like common sense, but its good to be verbose to prevent confusion.

Thanks for the help!

4

So with this configuration, are you able to set different max_power or kick_start_time for the two fans?

I am looking to add a second fan for parts cooling, but its of different size and air volume than my primary fan, so I am going to want to trim its speed by decreasing the max_power so its pushing the same volume as the primary fan is.

5

Those parameters are defined in the respective fan sections so it should be respected by multi pin and M106.
Best is you test it with those tips and recommendations.