Jump to content

Recommended Posts

Posted · First Layer Gouging

Recently figured out an issue that I was having with a print.  On the first layer, when the print head is moving to a new start position across the already laid down filament (PLA) it's "gouging" into that part of the print causing some very apparent scaring.  The second layer will cover it up to a certain extent, but the scar remains.  If you preview the gcode through Cura, you can see exactly where it moves across the print.  Is this something that can be prevented?  Also, the very center of the first layer goes back to a ZigZag pattern instead of staying concentric.  I'm running the latest version of Cura.  Pics show the first layer of the print and a closeup showing some of the problem areas.  Also attached is the gcode and stl for the file.

 

Any ideas?

 

Thanks,

 

 

Scan 1.png

Screenshot 2021-10-18_21-54-02-449.jpg

0.24 initial height.gcode profile.curaprofile top ring holder.stl

  • Link to post
    Share on other sites

    Posted · First Layer Gouging

    "Why isn't this line concentric instead of zig-zag?"

    The remaining center portion is not an exact "line width" wide and so a full line won't fit.  Cura fills it instead with a zig-zag pattern.  Remember that there are no circles, only shapes defined by a lot of chords.  The cross section therefore isn't 5.00000mm but varies according to how the chords are laid out which is a function of the triangles in the STL file.  The higher the resolution of the STL file means more triangles and the closer a model is to a circle, until you bump into Cura's Maximum Resolution setting in Mesh Fixes.

     

    The first image is "Bottom Pattern Initial Layer = Concentric" and "Line Width = .4" with "Fill Gaps Between Walls = Everywhere".

     

    Untitled4.thumb.png.ea198a326e2c895303728f6591776d25.png

     

    This one is with "Fill Gaps Between Walls = Nowhere"

    Untitled440.thumb.png.fa8f2f1ef57adaed16b0f776397fb1f5.png

     

    This one is with the Line Width = .37 (picked by experimenting).

     

    Untitled437.thumb.png.3162d29f86f3ea5f21fa19f74d942d78.png

     

    That bottom image can also be achieved by changing the Wall Thickness to 2.8.  With the current version of Cura it's always a matter of "how much room is left to fill?".

     

     

    The Cura Arachne version will vary the line width automatically to get rid of problems like that.  If you search around here there is a link to the Beta version of Arachne.  With the Line Width in Arachne at .4 you get the same pattern as that last image.

     

    Are you using Z-Hops?  If the retractions are set to occur over short moves then the nozzle should move up and not scuff the print.  Z-Hopping has it's own drawbacks but generally will eliminate scuffing.

    • Thanks 2
    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

      • Help Us Improve Cura – Join the Ultimaker Research Program
        🚀 Help Shape the Future of Cura and Digital Factory – Join Our Power User Research Program!
        We’re looking for active users of Cura and Digital Factory — across professional and educational use cases — to help us improve the next generation of our tools.
        Our Power User Research Program kicks off with a quick 15-minute interview to learn about your setup and workflows. If selected, you’ll be invited into a small group of users who get early access to features and help us shape the future of 3D printing software.

        🧪 What to Expect:
        A short 15-minute kickoff interview to help us get to know you If selected, bi-monthly research sessions (15–30 minutes) where we’ll test features, review workflows, or gather feedback Occasional invites to try out early prototypes or vote on upcoming improvements
        🎁 What You’ll Get:
         
        Selected participants receive a free 1-year Studio or Classroom license Early access to new features and tools A direct voice in what we build next
        👉 Interested? Please fill out this quick form
        Your feedback helps us make Cura Cloud more powerful, more intuitive, and more aligned with how you actually print and manage your workflow.
        Thanks for being part of the community,

        — The Ultimaker Software Team
        • 0 replies
      • Cura 5.10 stable released!
        The full stable release of Cura 5.10 has arrived, and it brings support for the new Ultimaker S8, as well as new materials and profiles for previously supported UltiMaker printers. Additionally, you can now control your models in Cura using a 3D SpaceMouse and more!
          • Like
        • 18 replies
    ×
    ×
    • Create New...