High power heater cartrdige PID settings?

C6D

Hello all,

I'm having a little bit of difficulty getting the best PID settings for my current printer setup.

Setup:
Duet
24V
DyzeEnd Pro with a 60W heater cartridge
PT100
Water cooled

I've run Autotune to 450deg C at 0.75PWM and the following figures were presented to me with a warning that the unit can reach 1060 deg C.

GAIN: 1035
Temp Constant: 378.5
Dead Time: 3.6

When I bench test these they worked well, I also setup start gcode for my less power hungry filaments which simply sets the PWM to 0.5. All this worked really well.

However when I put these figures into my printers config I keep getting heating up errors telling me the unit is not heating up fast enough.

Now I have deleted the config.overide from both machine as too be honest I don't know why it is there.

Could it be that somwhere else there is more failsafe PID settings which I'm missing?
Has anyone else experienced this? If so what can be done to fix it?

Any help would be greatly appreciated.

Cheers,

Andre

Phaedrux

If you're changing the PWM factor after the tuning that could explain it. You could run PID tuning at 75% and at 50% and then load those tuned values as needed.

I've run Autotune to 450deg C at 0.75PWM and the following figures were presented to me with a warning that the unit can reach 1060 deg C.

That 1060c figure is based on 75% power, and in a failure situation you would be getting 100% power, so that 1060c is lower than what you might actually get. 60w will slag your hotend in a failed on state. So definitely have some precautions in place.

C6D

Thank you very much for the reply.

I'll try that.

With regards to the config.override in the systems folder do you know what that is for?

A Former User

@C6D see https://duet3d.dozuki.com/Wiki/Gcode#Section_M501_Read_stored_parameters and also M500 to store them. Emulates marlin and repeteirs eeprom function, sort of.