3D Hardcopy: Converting Virtual Reality to Physical Models Sara McMains* Carlo Séquin Mike Bailey...
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Transcript of 3D Hardcopy: Converting Virtual Reality to Physical Models Sara McMains* Carlo Séquin Mike Bailey...
3D Hardcopy: Converting Virtual Reality to Physical Models
3D Hardcopy: Converting Virtual Reality to Physical Models
Sara McMains*Carlo SéquinMike Bailey
Rich Crawford
U.C. BerkeleyU.C. Berkeley}
U.T. AustinU.T. Austin
SDSC & UCSDSDSC & UCSD
*author of these slides – edited by C. H. Séquin
How Do We Make Physical Things ?How Do We Make Physical Things ?
Main Types of ManufacturingMain Types of Manufacturing
• Subtractive- remove material selectively from stock.
• Net shape- re-form material into new shape.
• Additive- build up material in chosen locations.
• Constructive- combine separately formed shapes.
Conventional ManufacturingConventional Manufacturing
• Subtractive– Start with simple stock– Remove unwanted volume– E.g.
•Machining(NC Milling)
Delcam
Conventional ManufacturingConventional Manufacturing
• Net shape– Start with simple stock (or powder)– Reshape in die or mold– E.g.
•Forging •Molding•Casting
Manufacturing by casting, stamping, NC machining …
Manufacturing by casting, stamping, NC machining …
• Appropriate for production runs– Incremental costs low
• Not appropriate for small batch sizes or prototyping– Complex process planning– Special purpose tooling– Set-up costs high– Long lead times
How Do We Make Quickly Complex Prototypes ?How Do We Make Quickly Complex Prototypes ?
Conventional ManufacturingConventional Manufacturing
• Constructive– Combine complex sub-units– E.g.
•Welding
Layered Manufacturing (LM)a.k.a. Solid Freeform Fabrication (SFF){ a.k.a. Rapid Prototyping (RP) }
Layered Manufacturing (LM)a.k.a. Solid Freeform Fabrication (SFF){ a.k.a. Rapid Prototyping (RP) }
• Additive- build-up of complex 3D shapes from 2.5D layers
Layered Manufacturing CharacteristicsLayered Manufacturing Characteristics
• Perfect for prototyping• Automated process planning
based on CAD model– Short lead times
• No special purpose tooling• Highly complex parts economical
at low production numbers
Benefits of LayersBenefits of Layers
Layering the manufacturing process eliminates constraints:
• No tool clearance constraints:– “Tool” is end of laser beam,– or a drop of glue.
• No mold releasability constraints:– Can make overhangs and undercuts.
• No fixture planning constraints:– As long as shape hangs together
LayersLayers
• 2.5-D slices through model– Slice interior defines part geometry– Slice complement may function as
fixture and/or support
Supports: - Plan ASupports: - Plan A
• All complement geometry on layer serves as support, e.g.:– Same material in unbound form:
(non-glued or un-fused powder).
– Same material with weaker structure:(fractal-like support pillars).
– Fill in with different sacrificial material:(which can be removed with solvent).
Supports: - Plan BSupports: - Plan B
• Supports with planned geometry– Identify overhanging features
• Top-down, layer-by-layer analysis.
– Selectively build supports beneath• Also layer by layer.
– May use same material as for part• Less dense fractal like pillars• Loose, brittle support sheets
– May use material different from part• Remove with selective solvent
LM Technologies ( Commercial – U.S.A. )LM Technologies ( Commercial – U.S.A. )
• Powder solidification– 3D Printing (3DP)– Selective Laser Sintering (SLS)
• Additive with sacrificial supports– Stereolithography (SLA) {= Liquid solidification}– Thermoplastic deposition
• Fused Deposition Modeling (FDM)• Solid Object Printing w/ Multi-Jet Modeling (MJM)• Solidscape’s ModelMaker {previously: Sanders}
• “Subtractive”– Laminated Object Manufacturing (LOM)
LM Industrial Applications
– Design review– Positives for molds– Functional testing
LM Medical Applications
– Prosthetics– Pharmaceuticals
• Micro-structure control
– Tissue engineering
LM Educational Applications
– Scientific Visualization– Topological Models– Tactile Mathematics
Hyperbolic parabaloid w/ Braille annotations (Stewart Dickson)
Klein Bottle Skeleton (SéquinSéquin)
San Diego Harbor (BaileyBailey)
LM Artistic Applications
– Jewelry– Sculpture
“Ora Squared” (Bathsheba Grossman)
CAD/RP Courses – Use of LM
• Scientific Parts• Math Models• Beautiful Artifacts• Fun Stuff !