Jump to content

Having trouble with being able to slice a 3d scan into a printable stl file.


agoodnight

Recommended Posts

Posted (edited) · Having trouble with being able to slice a 3d scan into a printable stl file.

Screenshot 2023-05-01 234934.pngModeling a grate, from a 3d scan. I popped it into Blender to clean it up, but then when I put it into Ultimaker the walls are not there when I slice the model.

 

Screenshot 2023-05-01 234949.png

Screenshot 2023-05-01 235047.png

Ornate_AirGrate.stl

Edited by agoodnight
  • Link to post
    Share on other sites

    Posted · Having trouble with being able to slice a 3d scan into a printable stl file.

    Your model is pretty bad.  Sorry to say.  When you scanned it you needed to scan the underside as well.

     

    As far as I can tell the walls are infinitely thin in most places.  So Cura is like - oh - infinitely thin - okay that just means zero plastic.  Done.

     

    So the model needs a lot more work in blender or other software.  Blender is designed for computer graphics where you can have infinitely thing objects and they look pretty good as long as you don't go around to the back side.  In 3d printing the models have to be solid.

     

    So some CAD software like design spark mechanical, autodesk, and hundreds of others only let you create "real" 3d objects.

     

    Other CAD software like blender and sketchup are geared towards computer graphics and will let you create non printable 3d scenes that may look great but aren't printable.

     

    There are lots of guides on youtube for how to fix your blender file to be printable.

     

     

    • Like 1
    Link to post
    Share on other sites

    Posted · Having trouble with being able to slice a 3d scan into a printable stl file.
    11 hours ago, gr5 said:

    Your model is pretty bad.  Sorry to say.  When you scanned it you needed to scan the underside as well.

     

    As far as I can tell the walls are infinitely thin in most places.  So Cura is like - oh - infinitely thin - okay that just means zero plastic.  Done.

     

    So the model needs a lot more work in blender or other software.  Blender is designed for computer graphics where you can have infinitely thing objects and they look pretty good as long as you don't go around to the back side.  In 3d printing the models have to be solid.

     

    So some CAD software like design spark mechanical, autodesk, and hundreds of others only let you create "real" 3d objects.

     

    Other CAD software like blender and sketchup are geared towards computer graphics and will let you create non printable 3d scenes that may look great but aren't printable.

     

    There are lots of guides on youtube for how to fix your blender file to be printable.

     

    Is there any way to fix my model without having to model the entire thing by hand, it is a 3d scan of an object that needs to be accurate.

  • Link to post
    Share on other sites

    Posted · Having trouble with being able to slice a 3d scan into a printable stl file.

    Your scan can't be very accurate at least out at the edges as the actual grate is much thicker than a sheet of paper, right?  Whereas your scan appears to be mostly thinner than a sheet of paper.

     

    Did you scan the bottom of the grate as well?

     

    I have only used blender a tiny bit but I seem to remember there is a function to thicken everything.  But that will change your accuracy. 

     

    Maybe @GregValiant has some ideas?  He's pretty good at fixing models but if he doesn't know which dimensions need to be accurate he'll have to guess.  I mean is the top scan accurate but the bottom surfaces are all just a guess?  That's what it looks like to me.  It looks like maybe you only scanned the top of the part and the scan software just assumed it *was* infinitely thin.

  • Link to post
    Share on other sites

    Posted · Having trouble with being able to slice a 3d scan into a printable stl file.

    Hello from sunny Florida.

    Scanning can lead to very accurate results but the point cloud must be interpreted correctly in the translation software.  20 years ago the forensic engineering firm I worked for used Rhino3D.  It was not cheap but did provide excellent results.  We were scanning wrecked cars so there was no printing involved but the scans were amazingly accurate.

     

    As @gr5 mentions this scan has serious issues as far as printing goes.  After repairing the model in MS 3D Builder I can still see right inside the shell.  Open seams like that make it impossible for Cura to slice it as Cura can't tell the inside from the outside of the model.  What you end up with is a shell that is infinitely thin and does not enclose a volume.  I tried some things to fix this but I didn't have any luck.  This seems like a translation software issue when going from the point cloud to a model.

     

    Your STL file can be translated into a DXF file and then can be modeled around that in CAD.  It's basicly a rectangle with a flange and with some fancy stuff inside.

    The rectangle would take a couple of minutes.  The other parts would take a while longer but there are really only 4 pieces to model.  The rest would be copies.  There are the 4 corner pieces, 4 mid pieces, the center piece, and the 4 knots that join the mid pieces to the center ring.

     

    I'll attach a DXF file here.  I don't know if it will be any use to you but I made it up so here it is.  It is at least a start for modeling in CAD as all the dimensions are going to be really close to your prototype part.  Time wise it's probably faster to just model it up than fooling around forever trying to get the scan to work.

     

    Sorry I couldn't be more helpful, but that's what I see here.

     

     

    MS3DB_Repaired_AirGrate.zip

    • Like 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 Universal Cura Projects in the UltiMaker Cura 5.7 beta
        Strap in for the first Cura release of 2024! This 5.7 beta release brings new material profiles as well as cloud printing for Method series printers, and introduces a powerful new way of sharing print settings using printer-agnostic project files! Also, if you want to download the cute dinosaur card holder featured below, it was specially designed for this release and can be found on Thingiverse! 
          • Like
        • 10 replies
      • S-Line Firmware 8.3.0 was released Nov. 20th on the "Latest" firmware branch.
        (Sorry, was out of office when this released)

        This update is for...
        All UltiMaker S series  
        New features
         
        Temperature status. During print preparation, the temperatures of the print cores and build plate will be shown on the display. This gives a better indication of the progress and remaining wait time. Save log files in paused state. It is now possible to save the printer's log files to USB if the currently active print job is paused. Previously, the Dump logs to USB option was only enabled if the printer was in idle state. Confirm print removal via Digital Factory. If the printer is connected to the Digital Factory, it is now possible to confirm the removal of a previous print job via the Digital Factory interface. This is useful in situations where the build plate is clear, but the operator forgot to select Confirm removal on the printer’s display. Visit this page for more information about this feature.
          • Like
        • 0 replies
    ×
    ×
    • Create New...