PID Tuning Number of Cycles
In coming from Marlan I am used to using the Cycles parameter for PID Tuning. Meaning that it will heat and cool the number of cycles i specified in the M303 command.
I do not see that option in the Duet. Is it not needed?
Based purely on the quality of the tuned results, it would appear it isn't.
So after running the PID tuning twice and inputing data in config.g, my tool temp is not fluctuating badly. I am trying to print at 230 but it keeps going from 226 to 232. Any ideas as to why. Here is my heater part of the config:
M305 P0 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 0
M307 H0 A90.00 C700 D10 V23.6 B0 ;PID Tuning Bed
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4725 C7.06e-8 ; Set thermistor + ADC parameters for heater 1
M307 H1 A260.3 C175.6 D1.1 S0.8 V23.8 B0 ;PID Tuning Hotend
M143 H1 S280 ; Set temperature limit for heater 1 to 280C
Are you tunning with the part cooling fan running as it would during a print? That can help get a more accurate model.
Are you using a silicone heater block sock? Those can help stabilize temps a great deal.
Are you sure you've got the right thermistor values for your particular thermistor?
Are you sure you've transcribed the PID values correctly? My preferred method is to use M500 to save the values to config-override and then copying those over to config.g
I also see you're using s0.8 to limit the own power. Have you tried tuning at full pwm duty cycle?
Have you seen this?
I did see that. To answer some of your other questions
Part cooling fan was on
Silicone sock was on
Thermistor value was from E3d website for the V6
Double checked on getting the same values into M307
I did not specify the S0.8, but that is what came back when I did the M307 command. I only had M303 H1 S275 as the imput.
Also I had the bed at printing temp and near the nozzle.
Phaedrux last edited by Phaedrux
So the bed was powered when tuning the hotend?
Try without and see if the values are much different.
Also, are you tuning from cold state?
Yes from a cold state. When this print is done I will try again without the bed powered.
If the results are the same you could experiment with reducing the dead time. It's at 1.1 in the value you provided. Try 2. I think that may help smooth out the waves.
Well I went through a number of tunings today. I have to set the PWM to .7 or lower to get rid of any waves. Also I decided to use the M500 command and use the config-override.g file to eliminate any transcribing errors to the config.g.
What is the heater cartridge?
@phaedrux 24v E3d
@GeorgeM I note that you have "D10" as part of the M307 command. is that what M303 gave you as an output?
Also check you config-override.g to see if there is not a different M307 in there
(note edited as I highlighed B0 instead of D10 originally)
@t3p3tony I dont remember now if that was from the M307 command or from the documentation.
@phaedrux Don't know. How/where would I find that?
@GeorgeM please run M303 again and post the results
You should read the documentation here that was linked already:
It looks form the original M307 you posted that the tuning value is not what you had configured
@t3p3tony I'm not home currently. Will redo tomorrow.