PID autotune fails for hotend

Re: PID autotune fails for hotend

dc42 — Sun, 07 Oct 2018 03:51:15 -0400

The message:

Quote

Warning: Auto tune of heater 1 failed due to bad curve fit (A=2048.7, C=131.1, D=5.7)

is telling you that the heater power is much too high. The values it gives may be correct for your hot end, but the firmware regards a gain (A parameter) above 1500 as indicating that something went wrong.

Re: PID autotune fails for hotend

Brummie — Sat, 06 Oct 2018 02:41:32 -0400

H word is the heater number.
You probably meant P word.

The point is, I tested for the max P value, that passes autotune successfully - but using those values in print raised the same error.

... but I got it anyway - had to reduce the P value even more.
First test print is already running :)

cheers

Re: PID autotune fails for hotend

o_lampe — Sat, 06 Oct 2018 02:36:06 -0400

You could reduce the H parameter to 0.5 and try again.

PID autotune fails for hotend

Brummie — Fri, 05 Oct 2018 23:52:34 -0400

Hello,

my heater was too weak to operate at higher temperatures, so I build a heater block for two heaters.
On first test the heater didn't stop at given temperature but jumped over 300°C - so I searched for pid tuning.

In GCode-console I entered: M303 H1 S230
... and this happened:

05:24:33 M303 H1 S230
Auto tuning heater 1 using target temperature 230.0°C and PWM 1.00 - do not leave printer unattended

05:24:39
Auto tune phase 1, heater on

Then an error message popped up saying

Error: Heating fault on heater 1, temperature excursion exceeded 15.0°C

Auto tuning went on with these messages

05:25:05
Auto tune phase 2, heater off

05:25:18
Auto tune phase 3, peak temperature was 292.2

05:27:20
Warning: Auto tune of heater 1 failed due to bad curve fit (A=2048.7, C=131.1, D=5.7)

Is there a way to manage this hotend?