E3Dv6 tuning

CButtaci

Hi, i've been trying to PID tune a E3Dv6, 30w. My config setting suggested after tuning are as follows;

;E3Dv6 Heater
M143 H1 S280 ; Set temperature limit for heater 1 to 280C
M305 P1 T100000 B4725 C7.06e-8 R4700 ; Set thermistor + ADC parameters for heater 1 (E3Dv6) R4700
M307 H1 A496.1 C243.8 D5.2 S0.5 B0 ; Heater tuning parameters

I'm struggling to keep a constant temperature at the hotend. If set the temperature to 220C (No FANS) it seems to fluctuate between 218C - 222.6C. Does that sound normal? I'm trying to print in VASE mode using clear PET-G which is giving me a sort of striped exterior. It seems to follow the fluctuating temperature variance.

My Prusa i3 MKII using Marlin seems to keep the correct temperature within 0.4C, even with the cooling fan switched on.

Cheers,
Charlie

EDIT: I'm running firmware v1.21 (2018-03-21) on a Duet v1.01

resam

Any reason why you limited your heater to 0.5 PWM? This is effectively only 15W out of 30W...
You can try to increase the D value, 8.0 or even 10.0 have worked for me in the past.
You can also try to lower your C value, maybe 200 or 150 would be worth trying.

CButtaci

Thanks Resam,

To be honest there was hardly any difference between PWM 1 and 0.5. I did try changing the dead time but not as high as that.

I'll give your suggestions a go.

Cheers.

dc42

If the temperature is oscillating regularly when the hot end is stationary, increase the dead time until the oscillations top.