Bed PID tuning and M307 settings

Aurimas

Hi guys,

I am pulling my hair out.
Duet3 Mini 5+ board - makes no difference
I have big bed that takes time to heat up.
fairly slow. it bombs out when heating.
I run PID tune. It gives the result, but complains that it was inconsistent.

see below:
Warning: heater behaviour was not consistent during tuning Auto tuning heater 0 completed after 4 idle and 25 tuning cycles in 3341 seconds. This heater needs the following M307 command: M307 H0 R0.246 K0.857:0.000 D2.04 E1.35 S1.00 B0 Send M500 to save this command in config-override.g

I add the settings into the config and straightaway it gives me an error when I am trying to heat it up
Error: Heater 0 fault: temperature rising too slowly: expected 2.18°C/sec measured 0.22°C/sec.

I tried changing R and D values - makes no difference at all. Expected rise value is still the same and always gives me an error.
do you guys have any ideas?

Phrayzur

@aurimas I've been having the same problem... Check this post out...

https://forum.duet3d.com/topic/28218/cr-10s-heated-bed-error-temp-rising-too-slowly

Phaedrux

How big is the bed? How powerful is the heater?

What values did you try for D?

Aurimas

@phaedrux as I said in the description - it is big. But it doesn't matter. After PID tune it should respond properly, but it doesn't. And that's the problem.
I have tried R values from 0.001 to 5 and D from 0.5 to 100.
The expected rise value is not changing and that is the problem

Aurimas

@phrayzur not related. I have done PID tune already - no good