Jump to content
Ultimaker Community of 3D Printing Experts

Recommended Posts

Posted · Prints Small, Circles Oblong

On the surface, this looks straight forward, but allow me to give some history.


User Story
I want to be able to print objects I design, with a +/- 0.5mm dimensional tolerance, and have circles and regularly polygons print with a consistent radius and all lines and angles within the polygon are congruent.

 

Symptoms
See the photo attached to this post.  About 2 weeks ago circles began printing ever-so-slight out-of-round.

Evidence

This is a standard S5.  It's about 2 years old, and has around 250hrs of print time on it.  It's always printed small objects smaller than they should be (some times as much as a full mm) but for the most part that's not a problem as long as holes are actually circles or regular polygons since any scale deviance in size can be resolved in the model or with some simple hand tools.

 

 I asked around and did some reading and most suggested tightening belts or re-calibrating.  I opted for the latter--I'm a bit remiss to do any disassembly on this machine.  I calibrated the Z-axis and got stuck.  The printer would fail to start the XY calibration, complaining about a height difference.  While searching for an answer, I noticed there was a firmware update from 5.8.1 to 5.8.2.  Did that.  

A post on this forum lead me to realize it might be a problem with the lift switch and so I watched that carefully and found it was missing the bracket to flip the switch.  I recalibrated the lift switch and could now print the XY calibration pattern.  

 

The thing I noticed at this time was that the Y portion is exactly the same size as on the paper calibration print out (in the Y direction), and all the tick marks match up with the numbers on the paper.  The X axis, however, is smaller that the calibration rectangle (in the X direction) and starting at the left-most position (-), gets further away from the numbers as the you look to the right (+).  Still, using this guide it looks like +1 is the way to go, but that doesn't help.

 

If X and Y adjustments are the same [(0.5, 0.5),(1.0,1.0), or (1.5,1.5)] circles are ovals, and polygons are skewed, but right angles with sides perfectly on the X and Y axis are straight.  If the X adjustment is larger than Y, I get a right angle trapezoid when printing the skirt, but printing a rectangular object prints a perfectly right-angled parallelogram as one would expect.

I've attached a photo of the before changes (before Z calibration) and after changes (current).
Before is Ultimaker White Tough PLA, from extruder 1(AA 0.4); the same setup I've used for a couple years.
Current is Polymaker Teal Polylite PETG (CPE) from extruder 2 (AA 0.4);
Changes:

  • Z-axis alignment
  • Firmware update
  • Calibrate lift switch
  • Calibrate XY
  • New Filament (first time using non-ultimaker filaments) using settings as recommended by SandervG in this post.

 

Conclusion

Something I have done has taken me from bad to worse and I'm outside my realm of expertise to resolve it.
I am not concerned about problems with infill or material adhesion at this point.

IMG_1160.jpeg

  • Link to post
    Share on other sites
    Posted (edited) · Prints Small, Circles Oblong

    This 20x20x20 cm cube comes out pretty well.  X and Z are spot on.  I really couldn't ask for any better precision.  Given the accuracy of those, the measurement for Y surprised me.  If X and Z were off by half of that deviance, I'd call it close enough for FDM.  But this is repeatable.  PLA, Tough PLA, ASA, and this CPE.
    Smaller than 10 cm, and X is smaller than the dimensions in the model.  Larger than 10 cm and X about right, but Y is larger than the model by about 10% of the model's dimension on the Y axis.  Print speed (30mm/s to 60mm/s) does not affect the tolerance by anything my tools can detect.

    Larger circles, hexagons, etc have less noticeable skew, but I attribute that to the woefully inaccurate nature of sight and our brains tendency to normalize what we see.

    Any help with diagnosing this is much appreciated.
    xyzCalibration_cube.stl
    IMG_1165.thumb.jpeg.4b274c832011964b4a2f73ac3af7d4f9.jpegIMG_1166.thumb.jpeg.599f3d27a3bdae4c5f179a5698c4adc8.jpegIMG_1168.thumb.jpeg.0d335a9f1dd1c5705291c2e765e015b0.jpeg

    Edited by celadon_one
    Confused my axis, corrected.
  • 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

      • Startups, apply for the Forward AM Innovation Award!
        Are you a startup using 3D printing? Perhaps you should continue reading... 
         
        Together with BASF we are launching the Forward AM Innovation Award - the very first global contest for startups developing new applications with 3D printing!
         
        Why apply?
        The winning startup will receive €100,000 in goods and services*, along with coaching and marketing exposure from top-notch leaders in the industry.
         

         
        Who can apply?
        Your startup creates products using Additive Manufacturing, is less than 5 years old, and has less than 50 employees. We are looking for 3D printing applications with a strong focus on innovation, sustainability and scalability.
         
        Dental aligners, shoes, tools, automotive parts, music instruments, industrial tooling and molding, medical implants, sports equipment, toys, architecture, fashion, construction... all are welcome to join!
         
        Do you have an innovative, sustainable and scalable idea that leverages the unique possibilities of 3D printing? Then it is time to apply!
        More information can be found here.
         
        Applications close on March 28th, 2021
        * What does "in goods and services" mean?
        The winner will be able to pick any item from the overall product and service portfolio of the sponsors, e.g. printers, materials, consulting, software... Choose whatever you need to accelerate your startup.
         
          • Like
        • 0 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...