Running PID Autotunning on my hotend
24v 40W heater, on E3D V6 1.75 with silicone cover
Sent Code M303 H1 P0.2 S240
Warning: Heater 1 appears to be over-powered and a fire risk! If left on at full power, its temperature is predicted to reach 798C.
Auto tune heater 1 with PWM=0.20 completed in 635 sec, maximum temperature reached 175.5C
Heater 1 model: gain 778.7, time constant 227.3, dead time 7.5, max PWM 1.00, in use: yes, mode: PID
Setpoint change: P7.0, I0.03, D36.5
Load change: P7.0, I0.35, D36.5
Why would it say its over-powered if it wasnt able to reach the set temperture? of 240C
I will try again with a higher P rating.
Also trying to run AutoPID on my Bed
which is a 110v 750W silicone heater connected to a SSR
Sent Code: M303 H0 P0.25 S80
It was heating up slowly. i thought it would time out as it took longer then 10 seconds per 1 degree
but then i got this error
Message was this.
Auto tune of heater 0 with P=0.25 S=80.0 cancelled because temperature limit exceeded. Use lower P or higher S in m303 command
If i lower the P I dont think it will hit the temp.
Setting a higher P setting with cause the Temp to overshoot even slightly.
how are you suppose to get Autotune to complete?
Dougal1957 last edited by
Increase the S parameter to allow the heater to reach the desired temp (the S AFAIK sets the max temp to allow the tune cycle to get to) sure DC will be allong to comment before long.
StephenRC last edited by
The S parameter may never be hit when autotuning. It's not used for the autotuning to reach, but as one not to exceed.
For the bed, I use 140 since it's less than the temp the thermal fuse I installed trips at.
As Stephen says, the temperature parameter is a "do not exceed" temperature, not a target temperature. So I suggest you increase it.