Special Heater out of control
I am using 2 Heaters
Heater6 = 150W
Heater7 = 100W
I am using it through Duet Expansion board (PWM Heater)
I have tuned it several time. but it is getting out of control temp increases or decrees by 15C.
here is my setting.
M307 H6 A113.8 C160.0 D49.5 S1.00 B0
M307 H7 A280.4 C232.7 D30.4 S1.00 B0
M570 S240 H6 P40 T25
M570 S240 H7 P40 T15
![alt text]( image url)
PID control is difficult when the heaters have such large dead times as those. You can try increasing the dead time (D parameter in M307) - try doubling it - but you may be better off switching to bang-bang control.
There is some more information at https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control#Section_Setting_the_model_parameters_manually.