Jump to content
UltiMaker Community of 3D Printing Experts

Superfluous top layer inside model


pemur
 Share

Recommended Posts

Posted · Superfluous top layer inside model

I have been printing hive modular drawers and outers from Thingiverse for a while, without problems,  Due to printer changes I've had to modify the start code in the gcode file (generated in Cura 4.9), and rather than edit each file I thought I'd just re-slice.  The outers are printed at 101%, to give some leeway in inserting the drawers.  But when I do this with Cura 4.10 it introduces an extra top layer at one particular row in the file:

 

 image.thumb.png.0f5d5f2c02233fadc232a0b7a84fc96e.png

 

 

All other rows in the file are correct, just walls. 

 

This doesn't happen at 100%, but trying 99% puts the extra layer at a different point, further up the object.  This appears to be a top layer (shown by swapping patters for top/bottom layers).  I have no idea where this is coming from - and equally cannot see how to remove or avoid it, other than printing at 100%, which won't match my previous drawers.  Any thoughts?

  • Link to post
    Share on other sites

    Posted · Superfluous top layer inside model

    A bit of further information - the anomaly only seems to happen with a Standard Quality (0.2mm) profile, switching to Dynamic (0.16mm) yields a perfectly formed product, albeit predicted 30% slower to print.

  • Link to post
    Share on other sites

    Posted · Superfluous top layer inside model

    OK, glad to hear there may be some answers, because it's puzzling me intensely.  Give me a run down of the possibilities and I'll work through 

     

    The model is from Thingiverse, 1743145, though I think it's present all over the place.  I've been using Cura 4.10 at Standard Quality profile (for Creality Ender-3 Pro) with no modifications, expanding the outer case to 101% to give some freedom of movement for the drawer.

     

    Playing with different quality settings shows the effect does not occur at anything other than a 0.2mm setting, but it is reproduced with CHEP's 4.10 Good profile (also 0.2mm).  Using different scales indicates it's perfectly all right at 100%, but 101% gives an extra skin at layer 58/389, whereas 99% gives the extra at layer 329/381.  Other scalings may or may not produce the anomaly, but usually at different layers depending on the scale - 97% for instance introduces it at layer 62/373.

     

    When slicing there's a definite pause at around the point the extra skin is generated.

     

    I've tried with nothing enabled in mesh fixes (though disabling Union Overlapping Volumes did mean significantly extended slice times), no change.

     

    What I did note is that the file includes an extra little bit of inner wall where the layer is added, not present at any other layer:

     

    image.png.8bfdabe6e821db5a17b574a1c28ef942.png

     

    Worst case is that I just dig out my old gcode, generated with Cura 4.9, and make manual edits in there (specifically to enable mesh levelling on the printer) so even if it isn't solvable nothing is really lost.

     

    TIA.

  • Link to post
    Share on other sites

    Posted (edited) · Superfluous top layer inside model

    A work-around seems to be changing the layer height to .21.

    I didn't find any errors in the model, but in wireframe it looks like this.  Of the 6 inside faces it's the only one that has this whatever-it-is feature (EDIT:  It's a logo).

    I think the odd slicing (dependent on scaling or layer height) is either a bug, or Cura is being fooled by this model and it's acting like a bug.  Either way I think maybe it should go up on GitHub.

    Untitled.thumb.png.f6e2f3b5fba477dc1b679053252ada3f.png

     

    HIVE_Module_V5.stl

    Edited by GregValiant
  • Link to post
    Share on other sites

    Posted · Superfluous top layer inside model
    8 minutes ago, GregValiant said:

    A work-around seems to be changing the layer height to .21.

    I didn't find any errors in the model, but in wireframe it looks like this.  Of the 6 inside faces it's the only one that has this whatever-it-is feature.

    I think the odd slicing (dependent on scaling or layer height) is either a bug, or Cura is being fooled by this model and it's acting like a bug.  Either way I think maybe it should go up on GitHub.

    Untitled.thumb.png.f6e2f3b5fba477dc1b679053252ada3f.png

     

    HIVE_Module_V5.stl 13.28 MB · 0 downloads

    If the issue only occurs with a certain layerheight, it's often because of something in the topology of the mesh. After all; if you change the layerheight, you also change where the slice happens (and thus change the shape of the 2D polygon we then work with). It could be that some specific geometry here is causing this issue. But yeah, please report this on GH. You can do that here: https://github.com/ultimaker/cura/issues

  • Link to post
    Share on other sites

    Posted · Superfluous top layer inside model
    55 minutes ago, GregValiant said:

    A work-around seems to be changing the layer height to .21.

    I didn't find any errors in the model, but in wireframe it looks like this.  Of the 6 inside faces it's the only one that has this whatever-it-is feature (EDIT:  It's a logo).

    I think the odd slicing (dependent on scaling or layer height) is either a bug, or Cura is being fooled by this model and it's acting like a bug.  Either way I think maybe it should go up on GitHub.

    Untitled.thumb.png.f6e2f3b5fba477dc1b679053252ada3f.png

     

    HIVE_Module_V5.stl 13.28 MB · 0 downloads

    I am using a logo-less V3 version, from some months back, where five of the faces are plain.  There's some pattern nonsense at the base of the sixth face, but no indication of variation anywhere near the problem layers.  I'll see if I can find any other pattern in the behaviour and, as suggested, fill in a github report - and revert to my old gcode for further prints.  Thanks.

  • Link to post
    Share on other sites

    Posted · Superfluous top layer inside model
    45 minutes ago, nallath said:

    If the issue only occurs with a certain layerheight, it's often because of something in the topology of the mesh. After all; if you change the layerheight, you also change where the slice happens (and thus change the shape of the 2D polygon we then work with). It could be that some specific geometry here is causing this issue. But yeah, please report this on GH. You can do that here: https://github.com/ultimaker/cura/issues

    Will do, thanks!

    • Like 1
    Link to post
    Share on other sites

    Posted · Superfluous top layer inside model

    After playing with the model some more I'm pretty sure it's the model file (this is the one with the logo).

    I opened the file in MS 3D Builder and scaled it to 101% and did a Save-As and then that file sliced OK in Cura.

    I re-opened the original file in 3D builder and immediately saved the file (over-wrote the original) and the model appears to slice correctly.

    There is something odd about the file and it's not showing up as a discernable error in the model.

    My expert professional opinion is that "sumpthin' ain't right".

    • Thanks 1
    Link to post
    Share on other sites

    Posted · Superfluous top layer inside model

    Just tried with the newer V5 version here and that one is weird - still gets an extra skin at 101% scaling, but 95% gives me four extra skins at different layers. Have added info to the github report.

  • Link to post
    Share on other sites

    Posted · Superfluous top layer inside model

    And what may be my final contribution here (because I am now weirded out entirely) - the location of any extra skin depends on the position of the model on the build plate.  Five identical copies, side by side, sliced simultaneously, all give different final results.  How that can be a feature of the model escapes me completely.

    Hive_V5x5.JPG

  • 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
     Share

    • Our picks

      • Here it is. The new UltiMaker S7
        The UltiMaker S7 is built on the success of the UltiMaker S5 and its design decisions were heavily based on feedback from customers.
         
         
        So what’s new?
        The obvious change is the S7’s height. It now includes an integrated Air Manager. This filters the exhaust air of every print and also improves build temperature stability. To further enclose the build chamber the S7 only has one magnetically latched door.
         
        The build stack has also been completely redesigned. A PEI-coated flexible steel build plate makes a big difference to productivity. Not only do you not need tools to pop a printed part off. But we also don’t recommend using or adhesion structures for UltiMaker materials (except PC, because...it’s PC). Along with that, 4 pins and 25 magnets make it easy to replace the flex plate perfectly – even with one hand.
         
        The re-engineered print head has an inductive sensor which reduces noise when probing the build plate. This effectively makes it much harder to not achieve a perfect first layer, improving overall print success. We also reversed the front fan direction (fewer plastic hairs, less maintenance), made the print core door magnets stronger, and add a sensor that helps avoid flooding.
         

         
        The UltiMaker S7 also includes quality of life improvements:
        Reliable bed tilt compensation (no more thumbscrews) 2.4 and 5 GHz Wi-Fi A 1080p camera (mounted higher for a better view) Compatibility with 280+ Marketplace materials Compatibility with S5 project files (no reslicing needed) And a whole lot more  
        Curious to see the S7 in action?
        We’re hosting a free tech demo on February 7.
        It will be live and you can ask any questions to our CTO, Miguel Calvo.
        Register here for the Webinar
          • Like
        • 13 replies
      • UltiMaker Cura 5.3.0-Alpha 🎄 Tree Support Spotlight 🎄
        Are you a fan of tree support, but dislike the removal process and the amount of filament it uses? Then we would like to invite you to try this special release of UltiMaker Cura. Brought to you by our special community contributor @thomasrahm
         
        We generated a special version of Cura 5.2 called 5.3.0 Alpha + Xmas. The only changes we introduced compared to UltiMaker Cura 5.2.1 are those which are needed for the new supports. So keep in mind, this is not a sneak peek for Cura 5.3 (there are some really cool new features coming up) but a spotlight release highlighting this new version of tree supports.  
          • Like
        • 17 replies
      • New here? Get ahead with a free onboarding course
        Hi,
         
        Often getting started is the most difficult part of any process. A good start sets you up for success and saves you time and energy that could be spent elsewhere. That is why we have a onboarding course ready for
        Ultimaker S5 Pro Bundle, Ultimaker S5, Ultimaker S3 Ultimaker 2+ Connect.   
        They're ready for you on the Ultimaker Academy platform. All you need to do to gain access is to register your product to gain free access. 
        Ready? Register your product here in just 60 seconds.
          • Like
        • 14 replies
    ×
    ×
    • Create New...