Heatbed and PID
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Just to confirm, you've got temp1 thermistor on the heater0 (bed) and temp0 thermistor on heater1 (hotend)?
And you've got a semitek thermistor on both bed and hot end?
Have you ever let the PID tune run to completion or have you always canceled it after a few hours?
Was tuning started from room temp?
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@phaedrux Yes for basically all the questions. I once let it run 3 hours, but then stoped it because i had to go away. The PID for the hotend works perfectly tho. I get really like 0 degree variation. But on the bed i just cant get it working.
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Can you post a photo of the bed assembly?
150x150x6mm and 300W of AC power should heat up fairly quickly, but maybe takes a lot longer to cool down. That's usually what the tuning cycle is waiting for the longest.
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@phaedrux
so this is what my bed assembly is looking like. Yes it needs kind of long to cool down.
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Is that a Voron0? Closed sides but open top?
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@phaedrux its a selfmade printer. Yes sides are closed by now, but top will get enclosed some time soon aswell.
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I believe there is plans to make the tuning cycle time limitable in such cases. Not sure when that's coming though.
As it is, you can probably get a good tune from it by letting it play out, though with a lot of heat retention that could take awhile.
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@phaedrux okay i will let it run trough now, im home all day so i hope it does not take like 10 hours xD
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@phaedrux so after a bit i got this message this time
Warning: heater behaviour was not consistent during tuning
Auto tuning heater 0 completed after 6 idle and 25 tuning cycles in 2735 seconds. This heater needs the following M307 command:
M307 H0 R1.189 C136.8 D6.60 S1.00 V23.8
Edit the M307 H0 command in config.g to match this. Omit the V parameter if the heater is not powered from VIN. -
@phaedrux okay so i was able to fix it. I let it run trough for like 4h, then i had it oscilating, so i rised the d value a bit and now im getting a stable temp.
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Glad you got it. A little manual nudging to get it stable is pretty common. The tuning algorithm is still being improved upon to better deal with the edge cases like very large beds or very high powered heaters or chamber heaters etc.
