Wednesday, February 17, 2016

File Preparation for 3D Printing - 3D Modeling and Conversion

3D Printing Tips: Making Your First Model Print Easier

Make the Model With Printing in Mind

  • This is the main focus in terms of making your first print job go smoothly. If you model accommodating for the intricacies of 3D printing, you'll never have problems.
    • Make sure the model is a continuous mesh

      It is often easier to build complicated shapes in 3D modeling programs by making them composed of multiple, less complicated shapes; unfortunately, this does not work for 3D printing - for the printer to work, the object being printed must be a single continuous shape/mesh.

      To print out shapes you have built previously using multiple shapes, you must go through the often long and tedious process of merging vertices and edges until it is a solid object.
    • Eliminate non-manifold geometry

      From Shapeways:
      "Generally, there are two types of non-manifold errors:

      1. Open Objects: When there are holes in the object (think: the opposite of 'watertight').
      2. Unwanted Faces: When a model has unwanted extra faces or edges. Sometimes this extra geometry is hard to spot by only looking at the outside of the model. "

      Most vendors require all edges to be 2 manifold - as in, each edge has exactly two faces attached to it. These errors, often caused by open (unconnected) edges or overlapping vertices/faces, can be very difficult to find.

      Read this article from Shapeways for more in-depth information on how to fix manifold errors:
      http://www.shapeways.com/tutorials/fixing-non-manifold-models
    • Check surface normal vector directions

      The surface normal (sometimes called a face normal) is the directional vector perpendicular to the surface of a 3D model. Every face has its own surface normal, and it should be facing outward, away from the model's surface.

      These issues should be easy to find and fix using lighting display settings (Each software is different, but generally):
      • Find lighting settings, turn off 2-sided lighting
      • Reversed surface normals will look black
      • Reverse the normals on those surfaces
    • Check vendor's printing requirements

      This step is one you should take early on to do both comparison shopping and to figure out what your design needs are based on available materials and minimum thicknesses. If you are using your own printer, the manual should have this information.

    Convert the File to a 3D Printer Ready Format

    • You've made your model following the guidelines above, and you're just about ready to print! As an extension of the last point, check your vendor as to what 3D file formats are accepted. Usually, application-specific formats will not be accepted, and you will need to use universal file types. The two most common formats will be OBJ and STL.
    If you need to convert an existing 3D model into OBJ/STL, try Spin3D, our 3D file converter program. Spin 3D converts between STL, 3DS, 3DP, 3MF, OBJ and PLY mesh file formats. No matter which program you use to create your 3D models and 3D designs, you can convert to your desired output format.

    Spin3D also allows for batch formatting, perfect if you have several 3D files you need to format for printing!

    Click on the link to download or purchase:


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