PID Tuning with Ultimaker 3 Extended

[k35 0]

Hi all,

 

we are using a material with our Ultimaker 3 Extended that needs to be printed a lot below 100 °C. Moreover, it is very sensitive to the printing temperature. When trying to print with it, we experienced an overshoot of 15 °C compared to the desired temperature and then a decaying fluctuation. I assume that this is caused  by unsuitable PID parameters (most probably the PID tuning was done for a higher reference temperature). With older Ultimakers it was possible to use M301 in the gcode to set PID parameters or M303 for the autotune. However, these do not seem to work with the new Griffin flavor of the gcode. Is there any possibility to adjust the PID parameters of the nozzles for the UM3E?

 

Thanks a lot in advance for any help!

[gr5 2,167]

The PID parameters can be modified in many ways including by storing them on the core itself.  So you could have a "low temperature core" that has a different set of PID values than normal.

 

You can play with PID values to find the best values using the command_util.py.  Have you used ssh to connect into your printer yet?  Here are a few of the steps:

 

First put your UM3 or S5 into developer mode - it's in the menus on the printer.  Your machine needs to be on your network (wifi or ethernet) if it isn't already.  Once it's on the network it will show the IP address at the top of the main screen.

Next you need ssh which is built into linux and Macintosh terminal but not windows.  For windows I recommend putty:
https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

In putty you don't type the "ssh" part but just put the ultimaker@111.222.333.444 part and click "open".

ssh ultimaker@1.2.3.4  (don't enter 1.2.3.4 - enter the ip address listed on your UM3)
username/password:   
ultimaker/ultimaker   (much easier than root/ultimaker as it takes you straight into the utility to do sendgcode)
 

At this point you can do:

select printer printer/head/0/slot/0
list

 

And you will see all the parameters for the left core.  To change one do for example:
set pid_Kp 5
 

Type list again to make sure it worked.

 

Then heat up the core manually on the front.  You can change parameters live.  If you remove and insert the core you will lose these values.  To save these values you can edit py files or json files on this linux computer inside the printer.  Which is a little dangerous - make sure you have an olimex cable first (I sell them if you are in usa) or you can modify them on the core itself which is safer.  Email me for more details or more questions.  Email me directly as I'm hesitant to explain how to modify the core on this forum.  I'm at gr _at_ gr5.org.  After emailing me check your spam folder as you have to go through a very simple approval process to get to me (prove you aren't a spamming robot).

 

Or post your email here and I'll email you directly but I might not check back into the forums until tomorrow so emailing me is much faster.