So You Bought a 3D Printer. Now What? David V. Black Walden School of Liberal Arts Provo, Utah

E-mail: [email protected]

Why 3D Printing? !  Join the Maker Movement! !  New technology skills = new jobs. Career and Technical Education. !  STEAM fields: Science – visualization of scientific data. Technology – a developing, innovative field. Engineering – design and prototyping. Art – sculpture and creativity. Mathematics – scale, proportion, coordinate systems, spatial thinking.

What is

Your Purpose for 3D Printing?

!  Tied to the needs of your curriculum. !  Fulfills and enhances standards - better than other equipment you could buy (opportunity cost). !  Defendable to your principal and school board. !  Sustainable – continuing expenses for filament, etc.

Expensive Paperweight? !  3D printers are expensive to buy and operate. !  One spool of filament costs $35, plus other accessories. !  Hard to “dial in” a 3D printer unless you’re willing to spend time to tinker and make adjustments. They are NOT plug and play! !  Getting consistently good results takes practice and experimentation.

Setting Up To Print !  Use 3M double-sided 468MP adhesive tape to stick a sheet of polyetherimide (PEI) to the build plate. !  Set the build plate temperature to 60° C. Mine was set to 110° C; parts were curling and peeling up upon cooling. !  Avoid sharp corners – they cool from two sides and curl. !  Largest contact surface should be on the build plate.

The 3D Printing Workflow !  Planning and sketches !  Basic modeling: Extrusion vs. vertex (mesh) models !  Booleans and advanced techniques !  Exporting and mesh repair !  Conversion to STL (or OBJ) !  Importing, positioning, & scaling !  Printer settings !  gCode creation and .x3g version !  Printing and cleaning

Planning and Sketches !  Orthographic (front, side, top) !  Isometric (non-perspective) !  Perspective !  Sketches can be scanned, imported into Adobe Photoshop for clean-up, then Illustrator to make shapes. !  Illustrator shapes can be extruded in 3D software.

Extruding Vector Shapes !  Adobe Illustrator can be used to create basic cross section shapes. !  These shapes can be imported and extruded into the 3rd dimension, with shapes switched out along extrusion path. !  Envelopes can modify exterior smoothness. !  Finished shapes can be converted to meshes and modified using Boolean operations, etc.

Vertex Modeling !  Basic techniques: Primitives Extrusions (shapes pushed into third dimension) Vertex modeling (chicken wire, polygons) Metaballs (blended shapes with “attraction”) Other modelers: text, terrains, plants, etc. !  Advanced techniques: Boolean operations (addition, cutting, intersection) Bones and character rigging Morphable models !  Converting from one modeler or software to another

Free 3D Modeling Software !  Make Human !  Sculptris by Pixologic !  ImageJ to Gimp height map !  123D Design (Autodesk iPad App) !  TinkerCad (Autodesk-online) !  SketchUp (Google) !  Blender !  Maya (Autodesk)

Make Human

!  Free open-source software with a morphable human figure. !  Has controls for adjusting face, head, arms, torso, legs, etc. !  Export as OBJ.

Sculptris !  Free program from Pixologic, makers of Zbrush. !  Works like a ball of clay, with modeling tools to pull and push vertices. !  Can import Make Human OBJ files, then add hair as spheres. !  Make basic object shape (eyebrows, mustache, hair) out of spheres, with large areas indented.

Adding Spheres !  Use the draw, crease, and other tools to add details. !  Smooth as needed. !  Set Details to moderately low – will add vertices as details are added – but not too much! !  Can activate main model or spheres independently.

Final Details and Additions !  Can zoom in and add very fine detail, beyond Make Human. !  Save model and export OBJ – all the shapes will save as one. !  Import into modeler of choice for Boolean operations (cutting off body, adding base and text).

ImageJ to Height Maps !  Ideal for science and math uses. !  ImageJ is free from National Institutes of Health. !  Turns an array of numbers (separated by commas) into a grayscale image or height map, which becomes a terrain in many 3D applications. !  Example: Periodic properties of the elements. !  Example: 3D Mars and Moon terrains.

Exporting and Mesh Repair !  Final models need to be vertex (mesh) models saved as STL (or maybe OBJ). !  MeshLab and NetFabb are good free options for inspecting and repairing meshes.

Object Import and Scaling !  Import and position models in printer software (Replicator G, etc.). !  Scaling the objects: The build plate in the software may not equal the actual build plate size. !  Grouped objects will be proportional, but must be exactly on the same level or the raft won’t print correctly.

Printing Software and gCode !  Choose settings: Two shells Feed rate and head speed Heated Build Plate (60°C) Extrusion temperature (220°C for PLA) Fill ratio Raft and support settings !  Supports not needed if overhang angle < 45 ° from vertical.

Saving on SD Card and Printing !  Save from ReplicatorG to SD card as an .x3g file. You can make changes to the gCode if needed. !  Choose file and print – printer will automatically heat up the extruders and print bed, then begin to print. !  Be sure printer is calibrated. !  Be ready for long print times (8 plus hours).

Printing Out Einstein: The Process

Cooling and Cleaning !  Allow to cool completely so the Polyetherimide will release. !  May need thin metal spatula or ruler to pry up edge. !  Break off raft and supports. !  Use metal files and sanding paper to clean up rough areas.

Recent Examples