MATLAB & 3D printing

1. MATLAB & 3D printing Creating A model by Brooklyn Gose Basics Types & Functionality The Coding Process Applications

2. 3D Printing: The basics • Also called additive manufacturing, this process involves a printer with XYZ axis which creates a 3-dimensional solid object from a digital model by laying down successive layers of material in different shapes. • Builds the object by deposition of material rather than by removal of material. • Mediums range from paper, plastic, powders, resins, metals. • Depending on your model, you will want a certain printer type and medium. • Two Main Types of Printers (among many) • Fused Deposition Modeling (FDM) • Selective Laser Melting (SLM)

3. Fused Deposition Modeling (FDM) Selective Laser Melting (SLM) Primarily read Standard Tessellation Language or STL files, our goal was to find or develop a code which allowed easy transcription of .m files into .stlfiles, and successfully print a model.

4. facetnormal nxnynz outerloop vertex v1x v1y v1z vertex v2x v2y v2z vertex v3x v3y v3z endloop endfacet THE STL FILE AKA STereoLithography File • Describes a closed surface in terms of triangular faces • Each triangle is described by cartesian coordinates of its three vertices and a normal vector oriented outward from the closed surface • A surface described by an STL-file must then be sliced into layers using an external software. This defines the path traced out by the printer

6. MatLab Logo: The L-Shaped Membrane 1) Break up each square element in the mesh into two triangular elements using the MatLab function Delauney. Notice That the mesh has no thickness…. http://blogs.mathworks.com/community/2013/06/20/paul-prints-the-l-shaped-membrane/?s_eid=PSM_4977#1f9d71f8-8030-43d7-a639-a0388376118e

7. 2) Make a shell out of the surface by projecting all the vertices of the triangles downward along normal vectors. 3) Creates a second surface with no thickness beneath the original. 4)Connect the two surfaces along their boundaries to define a third surface. http://blogs.mathworks.com/community/2013/06/20/paul-prints-the-l-shaped-membrane/?s_eid=PSM_4977#1f9d71f8-8030-43d7-a639-a0388376118e

8. STLWRITE • Creates STL file directly from .m script • Downloadable function created for MatLab that exports a binary STL (or ascii) formatted version of a script. • Requires that your code have triangulated patch called FV, a structure with fields ‘vertices’ and ‘faces’. stlwrite (filename , FV) http://www.mathworks.com/matlabcentral/fileexchange/20922-stlwrite-write-binary-or-ascii-stl-file

9. Additional Steps • STL file now needs to be sliced • Software called “Slic3r” (and others) cuts file up into 2-dimensional cross sections of data, readable by printer • Some printers read another basic format called G-Code. If that’s the case when you go to print, this software will generate a G-Code from your STL file. • Use MeshLab for a 3D preview http://slic3r.org/ http://meshlab.sourceforge.net/

10. Applications

14. Interested in Printing? • Eugene MakerSpace has printers for public use • Possibly getting a printer in the geophysics department • Email me if you’re interested in printing something or would like more info on how to prepare your model for a printer.

15. Links • MatLab L-Shaped Membrane Steps • http://blogs.mathworks.com/community/2013/06/20/paul-prints-the-l-shaped-membrane/ • STL WRITE • http://www.mathworks.com/matlabcentral/fileexchange/20922-stlwrite-write-binary-or-ascii-stl-file/content/stlwrite.m • Meshlab • http://meshlab.sourceforge.net • Slic3r • http://slic3r.org/ • Downloadable STL files • http://www.thingiverse.com/