silicone heat bed tuning

[tdybare69]

i have hooked my duet2 wifi to my 12v powers supply,and 750w silcone bed via a ssr. how do i fine tune the heat bed in the config files?

[Phaedrux]

You should run a PID tuning cycle on it.

https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

[tdybare69]

this is what i recievedfor the M303 H0.
M307 H0
Heater 0 model: gain 317.3, time constant 665.7, dead time 9.8, max PWM 1.00, calibration voltage 12.1, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P38.0, I0.470, D262.1
Computed PID parameters for load change: P38
M303 H1
PMM307 H1
Heater 1 model: gain 898.2, time constant 180.8, dead time 2.9, max PWM 1.00, calibration voltage 11.9, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P12.4, I0.541, D25.2
Computed PID parameters for load change: P12.

[zapta]

750W at 12v is about 60A. That's very high current and not a very common combination. what kind of wires are you using there?

[jens55]

He is using the 12V signal to control an SSR that switches a line voltage heat bed on and off. He is not using 12V for the actual heat bed.

[zapta]

@jens55, I see, this is a AC mains heater. Makes more sense.

[dc42]

@tdybare69 said in silicone heat bed tuning:

this is what i recievedfor the M303 H0.
M307 H0
Heater 0 model: gain 317.3, time constant 665.7, dead time 9.8, max PWM 1.00, calibration voltage 12.1, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P38.0, I0.470, D262.1
Computed PID parameters for load change: P38

That sounds reasonable (the PID parameters for load change have been truncated). You will get a warning about the temperature that might be reached at continuous full power, because of the high power of your bed heater; so you should include a thermal cutout in the bed heater circuit.

[tdybare69]

@zapta 14GA