Hotend Cooling fan behaving erratically Toolboard 1LC

Surgikill

Hi all,

I'm setting up a Duet3 6HC right now. I have a Toolboard on a Hemera. The Hotend cooling fan is plugged into 121.out2. For some reason, the RPM of this fan does not stay constant, even though it should be at 100% when the hotend is above 55C. M107 from Prusaslicer will reduce the rpm of the fan. Running heater tuning will also reduce the rpm of the fan. I do not know how much the rpm is being reduced, but there is a very audible difference.

Relevant config.g

;Tool 0 (supervolcano hemera)
M308 S1 P"121.temp0" Y"thermistor" T100000 B4138                ; configure sensor 1 as thermistor on pin 121.temp0
M950 H1 C"121.out0" T1                                          ; create nozzle heater output on 121.out0 and map it to sensor 1
M307 H1 B0 S1.00                                                ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280                                                    ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"out9" Q500                                            ; create fan 2 on pin out9 and set its frequency
M106 P0 C"CPAP Blower" S0 L0.15 X1.0 H-1                                                  ; set fan 2 value. Thermostatic control is turned off
M950 F1 C"121.out2" Q500                                        ; create fan 1 on pin 121.out2 and set its frequency
M106 P1 C"Hotend Fan" S1.0 H1 T55                                             ; set fan 1 value. Thermostatic control is turned on

; Tools
M563 P0 S"main" D0 H1 F0:1                                      ; define tool 0
G10 P0 X0 Y0 Z0                                                 ; set tool 0 axis offsets
G10 P0 R0 S0                                                    ; set initial tool 0 active and standby temperatures to 0C

TRATOON

@Surgikill is there a reason why you didn't use 121.out1 for your blower? Also, is there a reason you mapped both fan 0 & fan 1 to tool 1? If not, try changing the f parameter in m563 to just 0 as that is your part cooling fan.

Surgikill

@TRATOON That fixed it, thanks.

I used out2 because that's what I used I guess. Documentation said they were both good for fans, and the fan that I have is a 2 wire fan, so I didn't want to take up the more versatile output with a shitty fan. I might change it over to a 4 wire noctua. Need to see.

TRATOON

@Surgikill have you had any issues with your print cooling fan? Mine seems to always be running at 100% and doesn't responds to off/slow down commands.

Surgikill

@TRATOON I'm running a cpap blower, so I'm not using a part cooling fan on the toolboard. Port your config and I can take a look at it and see if I think there is anything odd about it.

It may also be your slicer settings. Not sure what slicer you are using, but maybe you have 'cooling fan always on' enabled?