Is it possible to tweak the bed heater algorithm?

KTW

My printer is practically unusable at this point, since the bed heater algorithm faults it almost every time i turn on the printer.
Is it possible to change the check, so I don't need to perform a M303+M307 every single time I need to use the printer?

Always the same error:
Error: Heater 0 fault: temperature rising much more slowly than the expected 0.2°C/sec

jay_s_uk

@KTW either save the outputted values into your config.g or use M500 to save the values into config-override (ensuring you have M501 at the end of your config)

KTW

If only it was this easy.
I am already doing this every time.

deckingman

@KTW Not sure if it'll work in this case but you could try M570 to adjust the fault detection parameters. So e.g. M570 H0 P10 T5 S300 would set the time to 10 seconds, the excursion value to 5 degrees and cancel the print after 5 minutes of exceeding those values.

matt3o

I also had to tweak my values. It is feasible but depends on your bed. What are you tuning params?

jay_s_uk

or roll back to 3.1.1 to use the other algorithms and then don't tune with the new ones.
I had to do that on the heated bed on one of my printers

KTW

@matt3o

M303 H0 S70
M307 H0 R0.363 C315.930:315.930 D5.30 S1.00 V24.4 B0

KTW

@deckingman
Thank you, I will try this.

deckingman

@KTW If that doesn't work, you could also try increasing the "D" (dead time) parameter in your M307. Try (say) 10 secs instead of the 5.3 that the tuning algorithm calculated.

dc42

@KTW please post your entire config.g file, also the config-override.g file if you have one.

matt3o

@KTW said in Is it possible to tweak the bed heater algorithm?:

@matt3o

M303 H0 S70
M307 H0 R0.363 C315.930:315.930 D5.30 S1.00 V24.4 B0

if it were my printer I would try

M307 H0 R0.3 C400 D6.5 S1.00 V24.4 B0

if you are on SSR you don't need V

KTW

@dc42 here is my config files.
I have added the command "M570 H0 P10 T5 S300" suggested by @deckingman and this seems to have helped.

config-override.g
config.g

Phaedrux

What kind of a heated bed is it?

KTW

@Phaedrux
It's a 220V silicone heater,
similar to this one:
https://makersupplies.dk/en/heatbed/823-heatbed-silicone-heatbed-300x300mm-220v-350w.html

matt3o

@KTW as far as I understand the problem is that the sensor is integrated, for some reason RRF can't cope with that.

Phaedrux

See the reason here: https://forum.duet3d.com/topic/22155/error-heater-0-fault-temperature-rising-much-more-slowly/9?_=1616081192454

There is still room for improvement on the new algorithm to better take into account the thermal mass of the bed plate itself.