[SOLVED] Heated bed PID auto tune failed.
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@dc42 said in Heated bed PID auto tune failed.:
@deckingman said in Heated bed PID auto tune failed.:
@dc42 said in Heated bed PID auto tune failed.:
I have it on my work list to improve the measurement of dead time during auto tuning.
I've always struggled in that respect with my big thick lump of aluminium tooling plate and have to manually change the auto tune value. No big deal as it's not something that needs to be done often, but it would be nice to see that improved if it's possible.Can you tell me what value auto tuning reports, what happens if you use that value, and what value you actually use to get good results?
Now you've got me. I made a note in my config of the date I last ran auto tune and it was 17-08-2017, so over a year ago. Thinking about it, (and my memory is a bit hazy) I seem to remember that prior to that time, I really struggled to get a successful tune, but you made some changes which fixed the problem that I had - it was something to do with the check it makes after the heater turns off (can't remember what that check is). So now that I think about, you may have fixed the dead time issue too.
I'll run another auto tune when I get chance - bed is hot at the moment and it'll take about 3 to 4 hrs to get down to ambient. I can say that I'm using D16.4 so that would indicate that it came from auto tune and not a post tune manual entry (I'd have rounded it to a whole second).
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@dc42
I'm sorry, but I think I'm doing something wrong...7:43:07 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=133.8, C=839.5, D=-0.5)
7:30:11 PM
Auto tune phase 3, peak temperature was 90.0
7:30:04 PM
Auto tune phase 2, heater off
7:22:08 PM
Auto tune phase 1, heater on
7:22:02 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
7:21:45 PM
M307 H0 A83.9 C552.1 D20.0
6:46:16 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=83.9, C=522.1, D=-0.3)
6:38:16 PM
Auto tune phase 3, peak temperature was 90.1
6:38:09 PM
Auto tune phase 2, heater off
6:31:45 PM
Auto tune phase 1, heater on
6:31:39 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
6:31:15 PM
M307 H0 A102.6 C642.0 D17.0
6:22:21 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=102.6, C=642.0, D=-0.1)
6:12:29 PM
Auto tune phase 3, peak temperature was 90.2
6:12:22 PM
Auto tune phase 2, heater off
6:05:14 PM
Auto tune phase 1, heater on
6:05:08 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
6:04:45 PM
M307 H0 A102.0 C633.4 D15.0
5:48:31 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=102.0, C=633.4, D=-0.9)
5:38:47 PM
Auto tune phase 3, peak temperature was 90.0
5:38:40 PM
Auto tune phase 2, heater off
5:31:40 PM
Auto tune phase 1, heater on
5:31:34 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
5:31:22 PM
M307 H0 A163.0 C1031.9 D12.0
5:21:56 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=163.0, C=1031.9, D=-0.3)
5:06:05 PM
Auto tune phase 3, peak temperature was 90.1
5:05:58 PM
Auto tune phase 2, heater off
4:57:09 PM
Auto tune phase 1, heater on
4:57:04 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
4:56:48 PM
M307 H0 A78.8 C487.0 D10.0
2:26:11 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=78.8, C=487.0, D=-0.9)
2:18:43 PM
Auto tune phase 3, peak temperature was 90.2
2:18:36 PM
Auto tune phase 2, heater off
2:12:24 PM
Auto tune phase 1, heater on
2:12:19 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
2:12:01 PM
M307 H0 A141.7 C892.4 D7.0
2:08:46 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=141.7, C=892.4, D=-0.7)
1:55:02 PM
Auto tune phase 3, peak temperature was 90.0
1:54:55 PM
Auto tune phase 2, heater off
1:46:39 PM
Auto tune phase 1, heater on
1:46:33 PM
M303 H0 S90
Auto tuning heater 0 using target temperature 90.0°C and PWM 1.00 - do not leave printer unattended
1:45:29 PM
Connection established!
1:45:29 PM
Page Load complete! -
@vapvap It's the negative dead time that's screwing it up but I don't know why you are getting that. Are you starting from a low ambient or are things really hot in your part of the world?
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@deckingman Normal room temperature (~20C).
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What happens if you use a lower target temperature such as 70C?
The bed needs to be allowed to cool down completely to room temperature between tuning attempts.
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
11:20:51 PM
M307 H0 A181.2 C1041.0 D4.0 P0.5
Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 206C.
11:20:43 PM
M307 H0 A181.2 C1041.0 D4.0 P0.6
Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 206C.
10:39:52 PM
M307 H0 A181.2 C1041.0 D4.0 P0.7
Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 206C.
10:39:27 PM
M307 H0 A181.2 C1041.0 D4.0 P0.8
Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 206C.
10:38:52 PM
M307 H0 A181.2 C1041.0 D4.0
Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 206C.
10:21:55 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=181.2, C=1041.0, D=-0.8)
10:05:55 PM
Auto tune phase 3, peak temperature was 70.3
10:05:48 PM
Auto tune phase 2, heater off
10:00:36 PM
Auto tune phase 1, heater on
10:00:30 PM
M303 H0 S70
Auto tuning heater 0 using target temperature 70.0°C and PWM 1.00 - do not leave printer unattended
10:00:00 PM
M307 H0
Heater 0 model: gain 90.0, time constant 700.0, dead time 30.0, max PWM 1.00, calibration voltage 0.0, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P46.3, I0.319, D971.8
Computed PID parameters for load change: P46.
9:59:31 PM
Connection established!
9:59:31 PM
Page Load complete! -
Try with those M307 settings. The warning message is usual when using a high-power bed heater.
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 -
This post is deleted! -
What type of heated bed is it?
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@phaedrux Aluminum disc 220mm (Delta Printer).
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In the end, I achieved a positive value.
But what to do next?
After all, the "auto tune" still does not work.7:20:11 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=183.8, C=1042.4, D=0.1)
7:04:11 PM
Auto tune phase 3, peak temperature was 70.3
7:04:04 PM
Auto tune phase 2, heater off
6:58:52 PM
Auto tune phase 1, heater on
6:58:46 PM
M303 H0 S70
Auto tuning heater 0 using target temperature 70.0°C and PWM 1.00 - do not leave printer unattended
6:58:30 PM
M307 H0
Heater 0 model: gain 188.4, time constant 1070.6, dead time 5.0, max PWM 1.00, calibration voltage 0.0, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P202.9, I2.773, D710.0
Computed PID parameters for load change: P2
6:58:23 PM
M307 H0 A188.4 C1070.6 D5.0
Warning: Heater 0 appears to be over-powered. If left on at full power, its temperature is predicted to reach 213C. -
@vapvap said in Heated bed PID auto tune failed.:
@phaedrux Aluminum disc 220mm (Delta Printer).
And what is the heating element?
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@phaedrux said in Heated bed PID auto tune failed.:
And what is the heating element?
https://www.amazon.co.uk/anycubic-MK3-Round-Aluminium-Diameter-Printers/dp/B01LZ36INV
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Ok, now is it wired as 12v or 24v? What is your power supply voltage and wattage?
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@vapvap said in Heated bed PID auto tune failed.:
https://www.amazon.co.uk/anycubic-MK3-Round-Aluminium-Diameter-Printers/dp/B01LZ36INV
Please note: There is no Thermister not installed on the card or including in the list. Please, install the precisely Thermister
The listing says the bed doesn't come with a thermistor. What thermistor are you using and do you have the right configuration values for it?
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@vapvap said in Heated bed PID auto tune failed.:
In the end, I achieved a positive value.
But what to do next?
After all, the "auto tune" still does not work.7:20:11 PM
Warning: Auto tune of heater 0 failed due to bad curve fit (A=183.8, C=1042.4, D=0.1)In your M307 command, use the A and C values reported by auto tuning, but try a value of 5 for D. Then heat the bed to a typical temperature and see how it performs. If the temperature oscillates, increase D some more.
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 In the end, everything worked. Many, many thanks for your help.
I did it Only because You shared your thoughts and experience with me.
Without you, I would never have done it.
In gratitude, let me share my experience with you.
It is not enough, it can be useful ...
With best regards.
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@dc42 After installing MOSFET, I again cannot autotune my PID.
After endless attempts, I just got ~ :
Warning: Auto tune of heater 0 failed due to bad curve fit (A=191.5, C=1032.9, D=-0.1)
8:14:49 PM
Auto tune phase 3, peak temperature was 80.0
8:14:42 PM
Auto tune phase 2, heater off
8:08:14 PM
Auto tune phase 1, heater on
8:08:08 PM
M303 H0 S80
Auto tuning heater 0 using target temperature 80.0°C and PWM 1.00 - do not leave printer unattended
7:34:06 PM
M307 H0 A190.3 C1026.6 D5.0Tell me please, is my MOSFET a bad idea, or am i doing something wrong?
Regards.
