New heater tuning algorithm

Deltasquare

What is the limit to the PID values that are available?
I have a very fast heater and would like to use the integrated PID tuning, but unfortunately it heats too quickly (3 seconds to target temp), until now I have only gotten errors. "not heating at expected rate"...

MikeS

@Deltasquare are you sure of your temperature readings? 20-200°C in 3 seconds is really fast. Is this a SpaceX motor at launch?

lui2004

Hi

i have updated my Duet wifi to newest RRF 3.2 what i must change to use the new heater tuning algorithm ?

thats my actual settings for heater:

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B3950 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0                          ; create bed heater output on bedheat and map it to sensor 0
M307 H0 B0 S1.00                               ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                        ; map heated bed to heater 0
M143 H0 S120                                   ; set temperature limit for heater 0 to 120C
M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.06e-8; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1                           ; create nozzle heater output on e0heat and map it to sensor 1
M143 H1 S280 								   ; set temperature limit for heater 1 to 300C
M307 H1 B0 S1.00

and how i can tune the bed and thermistor ?

thanks a lot

Phaedrux

@lui2004 You tune it as normal using M303

https://duet3d.dozuki.com/Wiki/Gcode?revisionid=HEAD#Section_M303_Run_heater_tuning

Deltasquare

@MikeS
I am 100% sure.
However it's not quite up there with the Marlin engine in sophistication.... but close.

Alucardi

This post is deleted!

lee7670

@dc42 now that 3.2 has been out for some time, would it be possible to get a better description of what the new M307 parameters do? the documentation is very vague and (https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control#Section_Manual_adjustments_to_the_heater_model_parameters) still refers to the deprecated parameter A (gain). Specifically, heater rate has no units on it. Would it be possible to see a quick diagram of what the heater loop looks like and where all the parameters feed in? I'll need to have one of our controls engineers fix a particularly troublesome heater and it would be good if they had a diagram of what's going on so we can tune on the fly.

dc42

@lee7670 I have updated the wiki page on heater tuning.

lee7670

@dc42 Thank you, this is very useful!

gorf26

Seeing the subject has been brought up again..

I have just change out my hotend and heater and tried auto tune, always finishes but seems to have errors and gives me the values for the 307 in config, after entering the new values and i turn on the heater to 210 i always get a heater fault not rising fast enough. but from watching the DWC the temp seems to be going up fast.
So returned and this time no error and a new pid value so i enter that and got the same heater fault

If i put just use the default m307 values with no pid values it heats up fine no errors..

also have a pt100 with the duet pt100 board and it a diet2 wifi

this is with firmware 3.2.2 release

Thanks gary

Phaedrux

@gorf26 Instead of manually copying the values, can you try using M500 to save them to config-override.g and then compare what you had to what it saved. See if there is a difference. What values are they?

dc42

@gorf26 what M307 values does it tell you to use when you tune it?

gorf26

@dc42

M307 H0 B0 A113.8 C611.3 D0.4 V23.0

I have gone ahead and installed 3.3RC3 and that has seemed to fix it, I tuned the hotend again and it tuned with no errors, used the m307 it suggested and when cooled down i heated it to 240c and no fault error now.

Still a little trouble with the bed tuning gives me a waring message every time and a suggested a m307 value
i enter that in the config and it heats up fine.. so guess i won't worry about it to much..

Thanks gary

Phaedrux

@gorf26 said in New heater tuning algorithm:

a waring message every time

The warning is normal. It's telling you how hot it predicts the heater could get in a failure situation.