1 Rapid Prototyping Laminated Object Manufacturing Selective Laser Sintering Stereolithography Fused Deposition Modeling Solid Ground Curing 3D Printing

2 What is Rapid Prototyping Builds parts Layer-By-Layer Class of technologies that construct physical models from CAD data Some what like a 3-D printer An Additive process Visual Aids or Design Testing Rapid Tooling or Rapid Production of parts

3 The Basic Process Create a CAD model of the design Convert the CAD model to STL format Slice the STL file into thin cross-sectional layers Construct the model one layer atop another Clean and finish the model

4 CAD MODEL Build a Model Solid Modeler Packages –Such as Pro-Engineer tend to represent objects more accurate then wire frame packages –Yield better results Existing CAD or Create a model for RP

5 Conversion to STL STL Format –Establish consistency –****.stl – stereolithography, the first RP technique –Represents a 3-D surface in an assembly of planar triangle Like facets of a cut jewel Planar elements –Can not represent curve surfaces exactly –Accuracy vs. manageability

6 Conversion to STL

7 The Slice Pre-processing program –Prepares STL file for build –Most program allows user to adjust the model Size Location Orientation

8 The Slice Orientation –Weaker and less accurate in the Z direction then in the x-y plane –Orientation partially determines the amount of time for build Higher in the Z – lot more time to build Place shortest dimension in the Z –Reduces the number of layers –Layers are slices from.01mm to.7 mm (technique)

9 The Slice Auxiliary Structure –Supports the model during build –Useful for delicate parts –Some time difficult to remove Damage to Model Poor surface finish

10 Layer by Layer Construction of the part –Several Techniques –Builds part one layer at a time Polymers Paper Wax Powdered Metal

11 Clean and Finish Final Step is post-processing –Removing prototype –Detaching supports –Curing (if needed) –Minor Cleaning –Surface treatment Sanding, sealing, painting and so on

12 Clean and Finish

13 Rapid Prototyping Techniques

14 Laminated Object Manufacturing Called LOM. (Helisys) Paper is coated heat-activated glue so it will stick. (spool) Paper is bonded with last piece with heated rollers. Design is cut out of paper with a laser. The excess paper is cross hatched for removal. Produces large parts. –Wood like texture

15 LOM Process

16 LOM Examples

17 Selective Laser Sintering Called SLS. (DTM – Carl Deckard) Melts powdered material a layer at a time. –Uses leveling rollers Laser is used to melt powdered material. –Traces part and sintering metal powder Makes functional parts. Many different powders can be used.

18 SLS Process

19 SLS Examples

20 Stereolithography Called SLA. (3D Systems –first 1986) Photosensitive liquid resin hardens when exposed to a laser. –Low-power high focused UV laser –Traces out layer, solidifying resin –Liquid epoxy or acrylate resin The part is created layer by layer. The part needs to be cured after it is created. Great accuracy and surface finish.

21 SLA Process

22 SLA Examples

23 SLA Examples Cont…

24 Fused Deposition Modeling Second Most Widely Used Filament of heated thermoplastic is extruded from the tip X-Y plane Like decorating a cake Platform lowered and head deposits a second layer upon the first ABS, PC, Casting Wax, Polyphenolsulfone

25 FDM SAMPLES

26 Solid Ground Curing SGC - (Cubical) Similar to stereolithography Uses UV light –Selectively hardens photosensitive polymers –Cures entire process at a time Photomask –Printed on glass plate –UV light passes through the mask to the polymer

27 SGC

28 3D Jet Printing Entire class of machines –3D Printing (3DP – MIT, Soligen Corp.) Powder (excess is blown off) –ZCORP 3D (Z corp.) Powder (excess is blown off) –Thermo-Jet (3D systems) Molten wax or polymer (no excess) The model is built up layer upon layer at a time. –Ink-jet printer head technology Different materials can be used. Versatile

29 3D Printing Process

30 3D Printing Examples

31 3D Printing Examples Cont…

32 3D Printing Examples Cont…

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