Bed PID tuning



  • Just switched the bed to PID as supposed to BangBang since i've got it hooked up to a external mosfet and a dedicated 24V 400w PSU (the rest of the machine runs on 12V).

    At the end of the tuning i got this messange (in "warning yellow") :

    "Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 220C.
    Auto tune heater 0 completed in 1176 sec
    Use M307 H0 to see the result, or M500 to save the result in config-override.g"

    Should i pay any attention to this? Can't really find anything about the subject anywhere.



  • Its just a warning telling you that you tuned the bed to a temperature significantly lower than what would be the expected steady state temperature in case of a failure leaving the bed powered on outside of the control loop. (which shouldn't happen).

    So its up to you to consider if in the unlikely scenario of a failure if 220C would pose a problem, or take measures to prevent 220C from being a possibility. (thermal fuse, lower voltage, screw connections with no flamable parts near the bed, etc)



  • @bearer
    That's what i kinda suspected, but isn't that just as likely to happen when/if it's running BangBang?



  • Possibly, but maybe the bit-bang tunign isn't able to predict the steady state temp?


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