Creating Manufacturing Files

[Exporting Objects to Manufacturing Files]

Rhino is great for its ability to easily import and export other file types making Rhino compatible with most other software including some open source software which is available for most fabrication equipment. FabLab Modules are becoming ever-more user-friendly, find what is best for your purposes.

http://kokompe.cba.mit.edu/fab/index.html

When you export to a format like 3DS, STL or DWG, Rhino has to convert from smooth NURBS surfaces to a polygon mesh representation made of triangles. To do a good approximation of the curved surfaces, Rhino can sometimes use a lot of polygons. The density of triangles can be adjusted when exporting. You can create a mesh object and export it, or Rhino can create the mesh during the export process.

There are two methods to export models to other formats. You can ‘Save As’ and choose a specific export format to export an entire model. You can select some objects and ‘Export Selected’ then choose a specific export format to export a portion of the model.


To export to 2D laser cut machine or CNC profile cutting

  • from a close surface use ‘UnrollSrf’ command, un-clicking explode
    ‘SelAll’/ ‘ExtractWireframe’/ ‘ProjectToCPlane’/ ‘Join’
  • Tip #7: To clean up a line file you may need to ‘SelDup’/ ‘Delete’/ ‘SelAll’ / ‘CloseCrv’


To export to CNC Surface milling
With the 3-axis milling machines it is possible to manufacture 2.5D patterns and 3D surfaces. The three axis are X, Y and Z, this means the milling tool is fitted perpendicular to the XY-plane and can move in the X and Y directions as well as up and down (Z direction). Be sure to note the maximum travel distance in the X, Y and Z direction on your machine and tool bit.

  • Scale Units
  • ‘Split’ based on depth of material (ShopBot does have function for splicing based on material function)
  • Create ‘Mesh’, ‘SelSrf’, ‘Hide’ polygon surfaces
  • Export as STL file


To export to 3D printing
Seamless mesh – Rhino creates triangles and quadrilateral meshes for export into various file formats. When surfaces are joined together in Rhino, the meshes along the joined edge have coincident vertices. If a mesh is generated from a solid, there will be no holes in the mesh. This is valuable for export to STL rapid prototyping files.

  • Scale Units 1:1 making sure not to exceed bed limits
  • Place at Origin (0,0)
  • Join all
  • Create a mesh
  • Export as STL file


[3D SURFACE SCULPTING]

Modeling a Mold 

  1. Model the positive of your object using the methods described above
  2. Model a box around the object which will represent your mold material in real scale
  3. Determine a part line(s) – where you want to split your object and the mold in half (or multiple pieces)
  4. Draw the part line on the mold box in an elevation or front view (a flat view – not perspective)
  5. Use the split command to have the part line split the model and the object into multiple pieces
  6. Rotate each piece so that the open (split) side is face up
  7. Add surfaces to opening between the object and mold boundary by adding a plane across the entire mold boundary and then split out the object.
  8. Add registration tabs, small nubs and dips that align the top and bottom of the mold
  9. Boolean Union each mold piece into a single shape
  10. Export to STL


Other Tutorials

Rhino FabLab

http://www.rhino3d.tv/

Resources

http://fab.cba.mit.edu/content/tools/molding&casting/EP_modeling%20&%20molding.html

http://fab.cba.mit.edu/content/tools

http://www.rhino3d.com/ 

http://www.rhino3d.com/support.htm

http://www.rhino3d.com/nurbs.htm

 
Rhino Scripting | Can be utilized to quickly automate exporting a 3D model into millable parts.

If you’re interested in the scripting the script editing interface for Rhino is called Monkey and can be downloaded here.

Monkey can be used to edit, run, debug and compile scripts.
http://wiki.mcneel.com/developer/monkeyforrhino4
Wiki http://wiki.mcneel.com/developer/rhinoscript

Labs, Plug-Ins, and Programs available for evaluation
http://www.rhino3d.com/download.htm
http://www.rhino3d.com/resources/

Plug-Ins

Grasshopper | http://www.grasshopper3d.com/ -A graphical algorithm editor for Rhino.

Firefly | http://www.fireflyexperiments.com/ -Used to bridge Grasshopper, the Arduino micro-controller, the internet and beyond, allows near real-time data flow between the digital and physical worlds, and reads/writes data to/from internet feeds, remote sensors and more.

Kangaroo | https://groups.google.com/group/kangaroophysics?hl=en -Live physics

Geco | http://utos.blogspot.com/ -Used to Link to Ecotect

WeaverBird | http://www.giuliopiacentino.com/weaverbird/ -Catmull-Clark smoothing, Loop smoothing, Sierpinski Triangles, Sierpinski carpet, Mesh Primitives, and Loop subdivision

Rabbit | http://morphocode.com/rabbit/ -L-Systems and Cellular Automata

Galapagos | http://www.grasshopper3d.com/profiles/blogs/evolutionary-principles -Evolutionary Solver (included with Grasshopper 0.8)

SSI | http://geometrygym.blogspot.com/ -Data exchange with IFC, GSA, Robot, SAP2000, Sofistik, Strand7, SpaceGass, SDNF, CIS/2, Digital Project, REVIT, Bentley and Tekla

DIVA | http://www.diva-for-rhino.com/ -Sustainable design with Radiance, Daysim, and Evalglare

GHowl | http://www.grasshopper3d.com/group/ghowl/forum/topics/ghowl-r46-available-for -connect Grasshopper with Excel files, iPads, iPods, iPhones, Processing, Pachube, etc.

Fabrication Examples
Laser Cut – Tension-Fit Module
http://fab.cba.mit.edu/classes/MIT/863.10/people/ella.peinovich/Assignments/Week_02/02_laser%20cut,%20tension-fit%20kit_page.html

CNC Cutting Sheet Metal
http://fab.cba.mit.edu/classes/MIT/863.10/people/ella.peinovich/Assignments/Week_04/04_nc%20metal_page.html

CNC Surface Sculpting – Chair
http://fab.cba.mit.edu/classes/MIT/863.10/people/ella.peinovich/Assignments/Week_04/00_chair%20design_page.html

CNC Surface Sculpting – Molds
http://fab.cba.mit.edu/classes/MIT/863.10/people/ella.peinovich/Assignments/Week_09/09_molding%20&%20casting_page.html

Slip Casting – CAD/CAM – Milled Foam Molds – Milled Wood Positives
http://www.flickr.com/photos/ny_sed/sets/72157622508843744/

Slump Casting – Construction Automation – Milled Foam Molds
http://www.flickr.com/photos/ny_sed/sets/72157623372438072/

Slip Casting – Haystack – Plaster Molds
http://www.flickr.com/photos/ny_sed/sets/72157624358025491/