What are the S5 firmware accel and jerk settings?

[jeffroe 3]

I have failed in all my searches, so thought I would try posting here.

 

As I understand it, when the box for Enable Acceleration Control and Enable Jerk Control are UNCHECKED in Cura, the acceleration values and jerk values default to the settings in the printer's firmware.  I would like to know what these "default" values are as I am trying to get parts that are both dimensionally accurate and reduce ringing and bulging corners in the test cubes I am printing.  I tried using 3000 for acceleration, but while this did reduce the ringing, it also increased the overall dims by about 0.2mm and the corners of the part are bulging.  (Note: the dims I measure don't include the corners).

 

I think it would be helpful to understand how far the value of 3000 is from the firmware default so I have a better chance of getting parts I am happy with.

 

Thanks!

[jeffroe 3]

Can this be queried via the ssh connection in developer mode?  I haven't been able to get this to work either.

[jeffroe 3]

Well, I just stumbled on the "list" command when logging in via SSH as ultimaker.  This spit out a lot of settings, including:

acceleration_xyz = 3000

jerk_xy = 20

 

This seems to indicate that my test print with accel set to 3000 (enabled accel control) came out different because I also adjusted the outer wall print speed from my currently chosen value.  I am running another test print with accel set to 3000, and outer wall back to my default of 35 to see if this produces a part similar to my previous prints with accel control disabled.

[gr5 2,026]

Note that you probably logged in as ultimaker/ultimaker but you can also log in as root/ultimaker and get access to all the python files there.

 

But I think you found what you are looking for.  I'm pretty sure those the the correct values.  I don't know why those are defaults when travel moves have a jerk of 50! And accel travel can go to 5000mm/s/s.  It seems like you would get more accuracy with maximum jerk and accel.  But you get less ringing with lower jerk and accel (ringing is visible and ugly  but vanishingly small compared to other sources of dimensional errors).  So I suppose it's a tradeoff - higher accuracy versus more beautiful.

 

There are quite a few differences between the nicest looking profiles and the most dimensionally accurate profiles.  Have you seen the new profiles in the beta cura?

 

Anyway, bulging corners are caused when the printer slows down for the corners yet the pressure is still high.  The simplest way to fix this is to lower the print speed down to around the jerk speed although 30mm/sec should be slow enough.  Other ways are to crank up the jerk and accel.

 

It also makes a lot of sense to cut the corners in the CAD model (and other modifications like make all vertical holes 0.4 to 0.5 larger in diameter than desired).  Just bring in the corners to compensate for what the printer does.  If you think it's bad for FFF printing you should see what it's like - all the crazy changes you have to do - to create an injection mold.  If you want 90 degree corners the CAD model actually has to be <90 or >90 (I forget which).  I assume most European and USA mechanical engineers don't deal with this as the CAD modifications tend to be done in Asia.  But for FFF printing it's done usually in-house and you have to do these tweaks.  

[jeffroe 3]

Thanks for the response.  I was logged in as ultimaker - I tried as root as well, but wasn't sure where to find the details there.

 

I am not aware of new cura profiles from the beta.  I will look for those.

 

I am happy with the "dimensional" profile I have now, but it would be nice to get rid of some of the ringing.  I just can't get rid of the ringing without bringing the dimensions out of spec (typically too big), and getting the corner bulges.  

 

And I realize that the sharp corners are not very realistic.  I just like using these as my test part because I have printed dozens of them now!

[jeffroe 3]

17 minutes ago, gr5 said:

 

There are quite a few differences between the nicest looking profiles and the most dimensionally accurate profiles.  Have you seen the new profiles in the beta cura?

 

Do you know if the profiles from the beta could be imported into 4.3?

 

We are in the midst of deploying several of the S5's here along with the software, and I don't want deal with pushing a beta version yet.

[jeffroe 3]

I just installed the beta alongside 4.3 so i could see the profile settings.

 

I see an "i" notice next to the profile name after I load it, and it states that extruder 2 doesn't have a visual profile, so defaults will be used.  Does this indicate a problem, or is it just notifying me that extruder 2 typically doesn't print anything that would be visual anyway (mostly supports), so default settings are used?  This same message shows up for all profiles other than "Default" versions.

[ultiarjan 1,221]

for curious people that don't want to install the beta, you can also just download the zip

https://github.com/Ultimaker/Cura/releases/tag/4.4-beta-pre-release

 

And check the new profiles (open fe in notepad++) in:

Downloads\Cura-4.4-beta-pre-release.zip\Cura-4.4-beta-pre-release\resources\intent\ultimaker_s5

 

Edited November 5, 2019 by ultiarjan

[jeffroe 3]

My initial take is that the profiles don't import correctly into Cura 4.3, even though it states that it was successfully imported.  The new profiles don't appear in the list of custom profiles.