Switching a Fan Between On and Thermostatic

CCS86

Hi guys,

I have a fan to cool my Maestro that is currently configured for thermostatic control with the following config lines:

M308 S2 Y"drivers" A"DRIVERS"                          ; configure sensor 2 as temperature warning and overheat flags on the TMC2660 on Duet
M308 S3 Y"mcu-temp" A"MCU"                             ; configure sensor 3 as thermistor on pin e1temp for left stepper
                    
M106 P2 H2:3 L1 X1 B0.3 T49                            ; set fan 2 value

After turning up the stepper current, I found that MCU temp isn't a great analog for stepper driver temp. With MCU temp only a few degrees above "resting" temp, I was throwing stepper driver overheat warnings.

My question is if I can keep thermostatic control as a default, and force the fan on full time during a print? Or, will turning the fan "on" overwrite the thermostatic control.

I could always reassert the thermostatic config in my end gcode, and I guess it would have to go in my stop.g file as well.

It would be even better if we could setup stepper driver as a true sensor, instead of just an overheat flag.

Phaedrux

@CCS86 said in Switching a Fan Between On and Thermostatic:

I could always reassert the thermostatic config in my end gcode, and I guess it would have to go in my stop.g file as well.

This is what I do. You can also tie the fan speed to the bed and hotend temp so that when they are at temp (and likely printing) the board cooling fan will also be running.

@CCS86 said in Switching a Fan Between On and Thermostatic:

It would be even better if we could setup stepper driver as a true sensor, instead of just an overheat flag.

You can if you have an open thermistor port and attach a thermistor to the driver. However you'd have to choose one driver to monitor which may or may not be representative of the other drivers.

In general the Maestro drivers run hotter than the Duet Wifi, and more cooling is required, so I think option 1 is probably the best way to go. More cooler is better than not enough cooling as electronics go.

CCS86

@Phaedrux said in Switching a Fan Between On and Thermostatic:

@CCS86 said in Switching a Fan Between On and Thermostatic:

I could always reassert the thermostatic config in my end gcode, and I guess it would have to go in my stop.g file as well.

This is what I do. You can also tie the fan speed to the bed and hotend temp so that when they are at temp (and likely printing) the board cooling fan will also be running.

@CCS86 said in Switching a Fan Between On and Thermostatic:

It would be even better if we could setup stepper driver as a true sensor, instead of just an overheat flag.

You can if you have an open thermistor port and attach a thermistor to the driver. However you'd have to choose one driver to monitor which may or may not be representative of the other drivers.

In general the Maestro drivers run hotter than the Duet Wifi, and more cooling is required, so I think option 1 is probably the best way to go. More cooler is better than not enough cooling as electronics go.

That's a good call on using bed and/or hotend temp!

Can you define thermostatic trigger temps per sensor?

Phaedrux

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

I don't think so...

CCS86

That's what I figured.

I'll just set the temp trigger to ~52* for both hot end and MCU. That will make sure that the fan is on during any print and cooldown period, plus if it is idle and gets hot for some reason.

Thanks!