What is Rapid Prototyping?

Transcription

1 Rapid Prototyping New Technologies for the Classroom

2 What is Rapid Prototyping? A set of processes that allows a concept or idea to be turned into a three-dimensional physical object, usually in a matter of hours or days, rather than weeks or months. A technology with wide applicability in product design, manufacturing, sales/marketing, advertising and education.

3 What is Rapid Prototyping? Unlike machining methods that are subtractive where material is removed to produce the desired shape

4 What is Rapid Prototyping?

5 What is Rapid Prototyping? Rapid Prototyping processes are additive objects are built from a 3-dimensional computer model in layers, without molds, forms, or machining.

6 Rapid Prototyping at MSOE? 1989 began with an NSF grant application to partially fund the purchase of first SLA machine 1991 formed RP Consortium with four charter members: Outboard Marine Corporation (now BRP), Kohler Company, Snap-on Tools and Harley-Davidson 1994 to 2003 purchased a LOM machine, an FDM unit, a DTM Sinterstation, an SLA-5000, and another FDM machine, the only university in the U.S. with all these capabilities 2008 moved into a larger RP lab with a total of 10 machines utilizing 15 different materials

7 Who is the Rapid Prototyping Consortium?

8 Why does RP have value? Reduces engineering changes Costs increase as the design moves from concept to product: $1,000,000 $100,000 $10,000 $1,000 Fail early to succeed sooner. $100 $10 $1 Conceptual Design Detail Design Prototype Tooling Production Field Service

9 What is common to all RP processes? Construct solid model on any CAD system. Translate model to a surface representation:.stl file format is common to all RP machines. Generate 2-D slices with path definitions using RP machine-specific or third-party software. Build object. Post-process the part. Provide the expected finish.

10 What are current RP processes? Stereolithography (SLA) Transparent/translucent parts with good surface finish Selective Laser Sintering (SLS) Good strength, thermal stability and chemical resistance Fused Deposition Modeling (FDM) Similar to injection-molded ABS, polycarbonate or sulfones 3-Dimensional Printing (3DP) Most are fast great for concept evaluation

11 Stereolithography

12 Stereolithography 1- laser 2- mirror 3- positioning mechanism 4- liquid polymer with photoinitiator 5- part

13 Stereolithography Minimal Finishing Finished and Lacquered

14 Selective Laser Sintering

15 Selective Laser Sintering 1- laser 2- mirror 3- roller 4- powder 5- powder chamber 6- process chamber 7- part

16 Selective Laser Sintering Use of glass-filled SLS provides higher stiffness (2-3X) with essentially the same surface finish as unfilled nylon polyamide

17 Fused Deposition Modeling

18 Fused Deposition Modeling 1- material spool 2- heated extrusion head 3- part 4- platform

19 Fused Deposition Modeling Polyphenylsulfone (PPSF)

20 Concept Modeling Machines (3DP) Known by various trade names Multi-Jet Modeling, PolyJet printing or generically as 3-Dimensional printing (3DP) Uses thermoplastic polymers (ABS), photopolymers (acrylates), starch or plaster Characterized by high production speed and ease of operation

21 Concept Modeling Machines Relatively low acquisition costs Operating costs can be higher than anticipated Most have poor dimensional accuracy and mechanical strength compared to other RP processes

22 3-Dimensional Printing (Z Corp )

23 Pros/Cons of Common RP Processes Stereolithography Selective Laser Sintering Fused Deposition Modeling 3-Dimensional Printing Technology in widest use Widest range of available RP materials (including metals) Relatively low cost systems Low acquisition costs; higher than expected material costs Transparent/translucent parts with good surface Multiple parts can be stacked within each build Compatible with office environments Most are fast great for concept evaluation Highest accuracy High strength with good thermal stability and chemical resistance Similar properties to injection-molded ABS, polycarbonate or sulfones Fair-to-poor strength and impact resistance Build volume as large as 20 x 20 x 23 Build volume: 14.5 x 12.5 x 17.5 Build volume: 16 x 14 x 16 Smaller build volumes: usually about 12 x 10 x 8 (varies) Limited strength and flexibility for some resins Can be used for tooling or direct manufacturing Slower than competing RP processes Easy to use and operate Can be a slow process for thickwalled parts Surface finish not as smooth as SLA parts Poor surface finish due to large slice thickness Relatively poor accuracy Largest number of alternative materials and sources High material and initial equipment costs Porosity may be a concern Limited choice of materials Not resistant to high temp or chemical exposure Most complex machine of all RP processes Lacks the strength of similar injection molded plastic part Limited use as a functional prototype (except for Objet)

24 How does the PLTW partnership work? PLTW-Wisconsin will join the Consortium as of January 1, 2011 and will have a block of RP build hours Schools eligible to participate can send student part files on an as-needed basis No need for paperwork or Purchase Orders Part files and cost quotes are exchanged electronically Turn-around time is typically 2-3 days after receipt of the approved part file

25 How does the PLTW partnership work? No charges for shipping of parts Teachers and students participating in the program can attend regular RPC meetings at no additional cost Teachers and students get access to MSOE research and technical assistance from RPC staff Contact Steve Salter, PTLW-Wisconsin Director, for more details on the program