Chamber Heater Control
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Hi.
I have a large chamber volume, and it takes a fairly long time for it to come up to temperature. I've been unable to get the DWC to successfully control it, because it times out before noticing an appreciable difference in temperature. Even the PID tuning routine does this. Is there a way to configure a heater as "best effort" or something so it doesn't abort the print if the temp isn't achieved?
-Ben
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@benha see https://docs.duet3d.com/User_manual/Connecting_hardware/Heaters_tuning#setting-the-model-parameters-manually.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@dc42 Ah! Thank you. I'll mess with that.
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I also have a chamber heater and to reach 90°C my heater has to run 100% all the time and must never stop. (If it stops some things would get messed up in my case.) So I actually set it to something like 95°C to 100°C. From time to time I get an emergency warning that the chamber heater could not achieve the set temperature (because ambient temperature fluctuates a bit) and the print pauses.
How to avoid this? Or what is the best way to deal with this?
It is bang-bang controlled and the values are:
M307 H3 R0.535 K0.731:0.000 D4.25 E1.35 S1.00 B1
Does this have to do something with the dead-time (value D)? Best would be to set a range of temperature, where there should be no heater warning - for example if the range is set to +/-20°C and the chamber heater temperature is set to 100°C, then there should not be a warning in any situation from 80-120°C. -
@Christoph13524 have you tried using the M570 command to increase the permitted temperature excursion?
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@dc42 Thanks a lot! This looks like exactly what I am looking for!
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@dc42 So I just added the command M570 H3 P10 T20 for my chamber heater and now I get a lot of random heater faults during normal operation that worked pretty good before.
The weird thing is that I now even get heater faults when the current temperature is only a few degrees away - shouldn't there be any fault with +/- 20 °C now?
The heater is freshly tuned.
