Jump to content
Ultimaker Community of 3D Printing Experts

Darker layers always on the same layers


Recommended Posts

Posted · Darker layers always on the same layers
1 minute ago, UbuntuBirdy said:

Could it be the height where the heat from the bed no longer reaches the layers but the fans are at 100% (perhaps the fans reach at exact this layer 100% and the temp at the nozzle drops down until the heat element can correct the temp) and their air is reflected from the bed so the layer is cooled twice?

 

Thx for the idea.

I found this shift in all distances to the bed, from 2-3mm to 40mm highest. So I would guess this is not the reason. Esp. in the benchy I can move the layer shift up and down by setting different top layer numbers.

  • Link to post
    Share on other sites
    Posted (edited) · Darker layers always on the same layers

    This is the (well, one of the multiple reasons) I abandoned cura. I never found a way to print a benchy without the split on that section, all the benchies I tried separated on that layer like if they were printed separately.

    This never happened with any other slicer, and I don't use jerk and acceleration either actually, or at least I tried both ways before.

    This along with the bugs that corrupts cura 4.0 machines and profiles at every restart (very common bug since 4.0, I read about it everyday...) made it impossible to use Cura for any purpose.

     

    This said.. the split happens on the first "top" layer, that's where the material on the top doesn't bond at all with the one under it, it's not like it partially melts in some points, it just doesn't on any point. As I said, they seem printed separately.

     

    benchy split.png

    Edited by redslifer
    • Like 1
    Link to post
    Share on other sites
    Posted · Darker layers always on the same layers
    On 5/6/2019 at 2:16 AM, baxi said:

    Finished now the slow print, speed 40/20, Acceleration 300, Jerk 7.

    No change, the line shift is still there.

     

    The slower the acceleration and jerk the bigger the issue. Assuming you have a um2 it should be 3000/20

     

    Try to print it rotated 45 degrees. If the problem goes away I would triple check also x/y alignment of the axis

    • Like 1
    Link to post
    Share on other sites
    Posted · Darker layers always on the same layers

    I see similar issues on some objects and I also did some tests some time ago. But I cannot confirm it is a slicer issue, I sliced it with Cura and S3D, both with the same result. It also depends on the color of the filament how much you see.

     

    For me, I did several calibrations on the x/y axles, but it was not the problem. I still think it is some kind of over/under extrusion in combination with speed and temperature. But I stopped investigating deeper, so I really appreciate the test series from baxi, which give a great overview of the problem.

    • Like 1
    Link to post
    Share on other sites
    Posted · Darker layers always on the same layers
    6 hours ago, neotko said:

     

    The slower the acceleration and jerk the bigger the issue. Assuming you have a um2 it should be 3000/20

     

    Try to print it rotated 45 degrees. If the problem goes away I would triple check also x/y alignment of the axis

    Thx for your ideas.

    Maybe I will try higher acc later.

     

    I already turned the print with no change in the shift. So it's not an axis problem.

  • Link to post
    Share on other sites
    Posted · Darker layers always on the same layers

    It would be nice to see more photos of the shift - especially ones that show the worst shift.

     

    One possibility is that you have "play" or "backlash" (look it up in wikipedia). With printers that have noticable backlash if you print the same layer clockwise versus counter clockwise you can get shifts like you seem to describe.

     

    I would check to see if the shifted layers are CW and the unshifted layers are CCW (or opposite).

     

    Many times people have reported a bug in cura versus some other slicer only to find out that it was a hardware issue and the only difference in slicers was some minor speed difference, CW versus CCW, "wipe distance" or other minor thing.  Sometimes a tiny change that shouldn't affect the print does affect the print.

    • Like 1
    Link to post
    Share on other sites
    Posted · Darker layers always on the same layers

    Cura will tell you.  In layer view go to a "good" layer with the vertical slider.  Then use the horizontal slider to see the order of printing.  Then repeat on a "bad" layer.

     

    You can do this with one of your projects that you have saved and then reslice it before doing this.  Or if you have the gcode file you can load that into cura and do the same thing.

     

    There are other gcode viewers also like repetier host, that show you each gcode and then highlight them in red on the model.  But for purposes of CW versus CCW, cura is most likely the best option by far.

     

  • Link to post
    Share on other sites
    Posted (edited) · Darker layers always on the same layers

    I am having the exactly same problem on the benchy , constant layer shift in front one line width at that layer... already have solution for that?hmmm

    WhatsApp Image 2020-04-05 at 3.18.29 AM.jpeg

    Edited by weisheng1998
    attach picture
  • Link to post
    Share on other sites
    Posted · Darker layers always on the same layers

    @baxi Could you find a solution for this problem at last. I always had this issues as well, finally found this thread. I cannot get rid off it, hoping you can answer me something.

     

    This issue appears in all prints I do, as well, for ages.

     

    Thanks,

    Hendrik

     

  • 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
    • 18 Visiting our virtual showroom

      1. 1. Have you visited our virtual showroom before?


        • Yes
        • No
      2. 2. If yes - what content did you find most interesting?


        • Information about Ultimaker ecosystem
        • Applications & application stories
        • Customer success stories
        • Webinar sessions
        • Material wall & ecosystem partners
        • New product introduction; software subscription plans
      3. 3. What of the below would make you consider visiting (again)?


        • New Live Ultimaker Webinar streams
        • ‘Ask Me Anything’ with industry experts or Ultimaker staff via main stage and public chat
        • New customer success stories
        • New applications
        • Presentations/news from ecosystem partners
        • Opportunity to meet representatives for an interactive tour
        • Helpful videos like Software tutorials
        • Other; leave input in a comment below!

    • Our picks

      • Ultimaker turns 10: A look back
        Ultimaker is turning 10 years old and that means it is story telling time! We'll explore 2010-2014, traveling through the evolution of the business from the Protobox and Ultimaker Original, to the major leaps forward with the Ultimaker 2 and Ultimaker 3.
          • Like
        • 0 replies
      • Ultimaker Transformation Summit
        Visit our virtual showroom and learn more about the Ultimaker ecosystem!
        • 14 replies
      • New here? Register your Ultimaker for free 3D printer 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
        • 0 replies
    ×
    ×
    • Create New...