Jump to content

Ultimaker 2+ Connect severe Pause and Resume bug!!


Recommended Posts

Posted (edited) · Ultimaker 2+ Connect severe Pause and Resume bug!!

Hi all,


I have noticed a severe bug in the Ultimaker 2+ Connect Pause and Resume functionality.

Pausing works (question: when is a pause actually performed in the gcode? What does the Engine wait for before it finally pauses the print after pressing the touchscreen??), but when I perform a resume, all of a sudden instead of printing circles (I was printing a Cylinder) of the outside, the printer is "stitching" a pattern, so it makes circles in a stuttering motion which results in a terrible outer surface. So basically instead of doing a smooth circle, it makes a stuttering movement in a circular pattern.

I assume that after resume, the printer did not restore all settings stored when pausing the print.


This makes it completely impossible for pausing and resuming a print.


Help solving this problem (maybe I am doing something wrong?) is much appreciated!!

Edited by kupfeli
  • Link to post
    Share on other sites

    • 2 months later...
    Posted (edited) · Ultimaker 2+ Connect severe Pause and Resume bug!!

    I believe this is due to what’s known as “buffer overrun” I’ve seen it on my own UM2+C as well as my UM2+ when printing over USB via OctoPrint. After a pause on my UM2+C, if the printer starts on an arc or circle, it begins to stutter, which you described as “stitching”. This is because arcs and circles are made up a bunch of linear moves and the printer runs out of buffer basically and results in the slow performance. This is also common when printing over USB because the serial connection has limited bandwidth. There's a Cura plugin designed to solve this called "ArcWelder" which combines these many linear moves into a single arc move which reduces the likelihood of a buffer overrun. But I'm not sure if this would be compatible with newer Ultimakers since they use a different flavor of g-code. The UM2+C also may not recognize the arc command, I know it recognizes a limited number of Marlin commands, hence why you have your workaround for pausing a print, since it doesn't recognize an M0


    What’s interesting is the latest version of FW for the Connect was supposed to address the buffering issue but my up to date machine still exhibits the “stuttering” after a pause. 

    Firmware Release Notes

    Edited by dfrez
    • Thanks 1
    Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
    • Our picks

      • Introducing the UltiMaker Factor 4
        We are happy to announce the next evolution in the UltiMaker 3D printer lineup: the UltiMaker Factor 4 industrial-grade 3D printer, designed to take manufacturing to new levels of efficiency and reliability. Factor 4 is an end-to-end 3D printing solution for light industrial applications
          • Thanks
          • Like
        • 3 replies
      • UltiMaker Cura 5.7 stable released
        Cura 5.7 is here and it brings a handy new workflow improvement when using Thingiverse and Cura together, as well as additional capabilities for Method series printers, and a powerful way of sharing print settings using new printer-agnostic project files! Read on to find out about all of these improvements and more. 
          • Like
        • 27 replies
    • Create New...