[REQUEST] Add optional temperature tolerance to bed heating M190
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EDIT: Using M116 H0 S[tolerance] works perfectly for this.
Hello,
I'd like to request a temperature tolerance for bed temperature waiting.
I have a bed that takes a minute to heatup, as such while heating up from cold it typically overshoots by ~1.5C. My uninvestigated hypothesis is the temperature takes a while to saturate the bed and become steady state, as such the top of the bed takes some time to reach temperature such that the heatloss from the bed in steady state to the amibent conditions is equivalent to the power input from the heater (cold bed loses less heat).
However once at steady state, my bed is rock-solid and will rarely differ from the nominal temperature, (maybe +- 0.1C). It would be nice to have a temperature tolerance so that I can wait for the bed to come into the tolerance (in my case, say 0.2C), wait ~15s, and then wait for the bed to come into tolerance again (because it would've overshot the target temp in it's non-steady state warming) to ensure the bed is actually at temp. This is more ideal than just putting a 5min wait timer as printing after the printer is already warmed up from a previous print, the delay doesn't occur to nearly the same extent (or at all) as the bed is already saturated.
My example implementation: M190 R[bed_temp] T[temp_tolerance]
Waits for the bed to heat/cool to the target temp within the temp tolerance specified by the T parameter. If T is not specified the default tolerance (I think it's 1.5C?) is used.
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@Merlin246 Sounds like an ideal problem to use a script to solve, that way you can tune it to match your system.
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@gloomyandy what do you mean by script?
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@Merlin246 A file with RRF conditional gcode in it, either called directly using M98 or use the feature that allows you to call a script/macro to implement gcodes that are not implemented directly by the firmware.
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@Merlin246, the way I deal with that is that I first heat up the bed and then heat the extruder. Heating the extruder takes about the right amount of time to stabilize the bed temperature. Of course it is not as elegant as to have a script do the warming up but it works very well.
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I think M116 can do what you're asking for.
M140 S[target] M116 H0 S[tolerance] -
Did you PID tune your bed heater? A well tuned bed should not overshoot in a relevant amount
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@oliof I did, and when the bed is fully heated it's rock solid. My hypothesis is that it takes a while for the bed to reach steady state, and as such the surface of the bed isn't at temperature, so it loses less heat than it does in steady state (because it's cooler).
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@achrn it does! Thanks for the suggestion, going to be using this from now on
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undefined T3P3Tony has marked this topic as solved
