Temperature oscillations - should I run PID calibration?
 
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peridot
(@peridot)
Eminent Member
Temperature oscillations - should I run PID calibration?

I just assembled a Mk2S kit, and it's printing well. I do notice, though, that the hot end temperature oscillates around the setpoint by perhaps five degrees. The oscillations take perhaps a minute to go through a full cycle. This happens whether printing or not (in particular, whether the part cooling fan is running or not), which suggests that the PID coefficients aren't quite right. I know that Marlin has a routine to autotune the PID coefficients, but this is a completely unmodified kit, so I would expect that the out-of-the-box coefficients are right. Is something wrong, or should I just run an autotune?

Posted : 10/05/2017 11:18 am
JeffJordan
(@jeffjordan)
Member Moderator
Re: Temperature oscillations - should I run PID calibration?

..., so I would expect that the out-of-the-box coefficients are right...
i can not confirm this assumption. there are too many factors that influence the closed loop control for the hotend temperature (accuracy of psu output voltage for example or variances in the assembly of the hotend).

do a PID calibration, thats for what it's for.

dem inscheniör is' nix zu schwör...

Posted : 10/05/2017 11:35 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Temperature oscillations - should I run PID calibration?

Upgrade to 3.0.11-RC1 which will do it all for you at the press of a button.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 10/05/2017 11:37 am
peridot
(@peridot)
Eminent Member
Topic starter answered:
Re: Temperature oscillations - should I run PID calibration?

Upgrade to 3.0.11-RC1 which will do it all for you at the press of a button.

Aha! Thanks. But I think I might wait until the firmware is actually released - I already have one experimental printer I've upgraded so much it doesn't work at all. I have pronterface set up, so it's no trouble to just send a PID calibration g-code over USB.

Anne

Posted : 10/05/2017 11:53 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Temperature oscillations - should I run PID calibration?

It is released here: https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.0.11-RC1

The only issue I have found is the "Change Filament" menu option during a print. Most of the time it performs the operation twice (debounce not properly implemented?)

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 10/05/2017 1:21 pm
peridot
(@peridot)
Eminent Member
Topic starter answered:
Re: Temperature oscillations - should I run PID calibration?

It is released here: https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.0.11-RC1

The only issue I have found is the "Change Filament" menu option during a print. Most of the time it performs the operation twice (debounce not properly implemented?)

Peter

I'm glad to hear you're trying it and it works, but the RC1 - as far as I know - means "release candidate 1", as in, not released yet. I'm okay with waiting until they deem it ready for release.

Anne

Posted : 10/05/2017 4:29 pm
JeffJordan
(@jeffjordan)
Member Moderator
Re: Temperature oscillations - should I run PID calibration?

i tried the pid calibration inside 3.0.10-11 (the last one before the release candidate) and it worked.
but i wasn't really satisfied with the result. the build-in pid tuning did a 5 cycle tuning, so i went back tuning it with M303 E0 S200 C8.
don't know if they've increased the number of cycles with rc1.

dem inscheniör is' nix zu schwör...

Posted : 10/05/2017 6:59 pm
cory.w
(@cory-w)
Estimable Member
Re: Temperature oscillations - should I run PID calibration?

The new firmware is on the drivers page if I'm not mistaken. It's included in the updated pack with all the software. Not individually listed on just the firmware section yet.

Posted : 10/05/2017 7:50 pm
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Temperature oscillations - should I run PID calibration?

i tried the pid calibration inside 3.0.10-11 (the last one before the release candidate) and it worked.
but i wasn't really satisfied with the result..

Jeff

I agree with you on this. Furthermore this approach is a one-size-fits-all. PID settings at 205 degrees are not the same as at 255 degrees.

My simplistic mind believes that PID settings should be related to and set in filament GCode (and if you tell me that you don't have a "Filament/Material GCode" section, then I will tell you to use a decent slicer... 😉 )..

I also have issues with the probe temp calibration. In my office ambient is 15 to 20 degrees hotter in the summer than in winter and that will surely affect this automated approach.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 11/05/2017 3:57 pm
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