temperature fluctuation with hexagon hotend

Hi guys,

I have a Hexagon hotend that I bought from Makerfarm, last year. I haven’t been able to get it up and running because of a bad streak of circumstances, which I have been able to solve all but one.
Whatever I did, I have temperature fluctuations-
Here is a video of my Hexagon trying to settle on 245 C

https://www.youtube.com/watch?v=qdjnpahq97o

I have tried with support guys, and we ran through all the firmware they have for flashing since my TAZ is 3.1 version
not one of them manage to solve the temperature bounce.

So I am asking for some fresh perspective. What could be causing this?

Thank you

Have you ran the PID auto tune?

https://www.lulzbot.com/support/fine-tune-your-marlin-pid-settings

hi nopick,

Yes I have ran it. It does the same bounce during the process

Are the PID number you get from running the calibration the same as the ones being used in the code?

You need to update the PID numbers in the firmware and save it before they will be applied.

Hi and thank you,

If by update and save you mean M500 command, I did that.
The video you see above, it is the fluctuation of temperature during the actual PID tune. It never settles so I don’t think the tune has any affect. Or maybe I am missing what you are saying?

Hi,
how should I check that?
As I said, in the video above I recorded actual PID tune and you can see the bounce during it. Since it never settles I don’t think the tune is done properly at all. Even though I use M500 command to save it to EEPROM…
thank you

The PID tune gives you P = I = D = values you have to save back to the controller board. It does not save them for you. I do not have an example output to use to demonstrate what you need to do. :blush:

You can see your current PID values in the temperature section on the printer’s LCD.

Can you post a temp plot of the extruder during warm up and at steady state?

Thanks guys,

I have managed to solve the issue I think. Still need to do some test prints, but it looks like my hexa is operational.
I had to manually set the PID values through LCD.

Now I shall share my shame for the benefit of the others-

I never understood the following link well enough-
https://www.lulzbot.com/support/fine-tune-your-marlin-pid-settings

It says somwhere in the bottom that you just type in m500 and the PID settings are saved. It also mentions Slic3r and putting the PID values in your start G-code…

So this is probably the first time I did PID correctly, by substituting the values through my LCD…

cheers