PID'd bed keeps failing on heat up
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Ladies and gents,
Quick sanity check I guess.
To PID tune bed you do "M303 H0 S70" and "M307 ..." output you dump into your config file and it's good to go after the reboot right?!
If I've missed something can someone please remind me?!If I'm right then I do have a problem... Every time (95%) I heat the bed from room temp (20ish) it goes up to to 45-55c and fails without reaching set temp (eg 70c) with lovely "Error: Heater 0 fault: temperature rising too slowly: expected 0.30°C/sec measured 0.08°C/sec"
I've done dozen of PID tunes in case of whatever the reason but it's still not happy, also it completes PID fine without any extra warnings.
If I heat the bed in 2x stages, 1st set to 40c and then when stable set to 70c - no problems what so ever.
This one is a bit iffy heated bed solution for sure but sure thing after PID it should "familiarise" itself with the thing right?!
(I've retrofitted Up Plus with Duet board, it has 80w super volcano like heater cartridge in the block bellow the bed)Thanks a bunch
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@kr15_uk It's happening to me as well. I'm installing a Mini 5+ on an Ender 3 clone (better than saying Xvico Pioneer). If someone provides an answer, I'll link to you so I get it too.
Thanks for asking this question.
Mac
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Firmware version?
What M307 command did PID tuning give you?
Is the temperature reading otherwise stable?
How does the temp graph look in DWC?
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@phaedrux
M307 HO R0.491 K0.745:0.000 D6.25 E1.35 S1.00 B0
(See screenshot of successful no warnings PID tune)When it gets to the temperature it's all happy and stabile.
Did just now PID, updated config file with new parameter, let bed to cool down to ambient temp (25c today) and set it to heat up to 70c - it failed at 58c so I had to reset the heater and resume heating, it reached 70c and been sitting on it for 10mins now stabile flat.
And I'm all up to date on latest firmware and DWC (3.4.1) but it's been like this for a while now, I believe as far as 3.2 but I might be wrong on specific version but it's been a while.
Thanks.
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Thanks for the details. I've noticed a few faults like this myself in recent firmware.
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@phaedrux I think it needs some sort of "soak" time, that could be configured, that would allow thicker beds to come up to temp before the PID tune is started.
Owns various duet boards and is the main wiki maintainer for the Teamgloomy LPC/STM32 port of RRF. Assume I'm running whatever the latest beta/stable build is
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@kr15_uk I had the exact same issue then i switched to a new thermistor and the problem stopped.
Now im getting the opposite error on my hotend ....
lol -
I can report a very similar behaviour regarding heated chambers. PID tunning works, the tunning completes. But then using the reported values, heating always fails with the same error you have.
This behavour in my case started with 3.4 firmware, with old style PID it was working ok, so I guess the new PID model is not having a happy time with very slow heating elements? -
@jay_s_uk said in PID'd bed keeps failing on heat up:
@phaedrux I think it needs some sort of "soak" time, that could be configured, that would allow thicker beds to come up to temp before the PID tune is started.
I have an 8mm aluminum plate over the silicone heating mat.
The thermistor is in the middle of the silicone heating mat.
The silicone heating mat is insulated at the bottom with a 10mm cork plate.I don't think an additional warm-up time for the aluminum plate will have any effect or change anything in the measurement result !?
Except the thermistor is a bit away from the heating mat, which I have never seen before.Google Translate
----- Original Text -----Ich habe eine 8mm Aluplatte über der Silikon-Heizmatte.
Der Thermistor ist in der Mitte der Silikon-Heizmatte.
Gedämmt wird die Silikon-Heizmatte nach unten mit einer 10mm Korkplatte.Ich denke eine zusätzliche Aufwärmzeit für die Aluplatte wird nichts bewirken bzw am Messergebnis etwas ändern !?
Außer der Thermistor ist etwas vom der Heizmatte entfernt, was ich so aber bis jetzt noch nie gesehen habe. -
@kr15_uk said in PID'd bed keeps failing on heat up:
...it has 80w super volcano like heater cartridge in the block bellow the bed
A heater cartridge under the bed ?
I would like to see a photo of that.
Did you also specify the correct value for the thermistor in config.g, such as M308 S0 P"bedtemp" Y"thermistor" T100000 B4138 ?
Google Translate
----- Original Text -----
Eine Heizpatrone unter dem Bett ?
Davon würde ich gerne mal ein Foto sehen.Hast Du denn auch den richtigen Werte für den Thermistor in der config.g angegeben, wie zB M308 S0 P"bedtemp" Y"thermistor" T100000 B4138 ?
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@tinchus same here.. did you ever find out how or just buy an old duet2 and dont update it??
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undefined Phaedrux referenced this topic
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@rexx you can downgrade firmware quite easily, haven't downgraded my one yet though, I believe in good ppl fixing the issue at some, naive - perhaps!
For the time being I've added couple of lines into my start gcode to do "staged" heating up which works well for me.
M140 S40
G28
G1 Z140 F300
G28
M140 S50
G28
G1 Z140 F300
G28
M140 S60
....It goes to 40c fine 1st go but then needs extra "dwell" time so by adding slow moves gives that extra time... Not great by no means but oh well, it's temporary right?! Right??!
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@Tinchus @rexx @kr15_uk If you are having heater problems please see this post by @DC42: https://forum.duet3d.com/post/291170
He provides details of what he would like you to do to help him work out what the problem is....
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@gloomyandy
on it i will have a lookthank you
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@gloomyandy Wil do, Im pleased to help
