1. A presentation on Rapid Prototyping Siddhesh Keluskar Indian Institute of Technology, Kharagpur

2. Content • Introduction • Need • Process • Methods • Applications • Advantages • Summary • References

3. Definition • Rapid Prototyping (RP) can be defined as a group of techniques used to quickly fabricate a scale model of a part or assembly using three-dimensional computer aided design (CAD) data.

4. Need for Rapid Prototyping • To decrease development time. • To decrease costly mistakes. • To minimize sustaining engineering changes. • To increase effective communication. • Give engineers, manufacturers, marketing and purchasing personals a look at product in early design stages. • To identify faults and errors well in advance. • Increasing number of variants of products.

5. Process

6. 3D CAD model of the design in standard formats like .DWG, .IGES, .STEP is taken. The model is broken into several layers along Z-direction. Z direction http://blog.123dapp.com/files/Autodesk_123D_Make.png

7. Convert CAD to .STL format, with predefined step size that is layer size. • The RP machine processes the .STL file by creating sliced layers of the model. • The first layer of the physical model is created. • The model is then lowered by the thickness of the next layer, and the process is repeated until completion of the model. • The model and any supports are removed. • The surface of the model is then finished and cleaned.

8. Different methods for Rapid Prototyping • Stereo lithography • Selective Laser Sintering • Fused Deposition Modelling • Laminated Object Manufacturing

9. Stereo lithography • Polymerization of photosensitive liquid resin by laser beam. • The reaction in presence of laser causes resin to harden. • The scanning laser creates layer by layer image along Z-axis. • The platform is lowered and process is repeated.

10. Stereo lithography http://www.custompartnet.com/wu/stereolithography

11. http://upload.wikimedia.org/wikipedia/commons/1/1e/Stereolithography_apparatus.jpghttp://upload.wikimedia.org/wikipedia/commons/1/1e/Stereolithography_apparatus.jpg

12. Selective Laser Sintering • Fine polymeric powder like polystyrene, polycarbonate or polyamide is used • Preheated bed is used • Laser beam is used to heat and fuse the powder thus creating a layer • The bed is lowered by distance equal to layer thickness and process repeats.

13. Selective layer sintering http://en.wikipedia.org/wiki/Selective_laser_sintering

14. http://www.custompartnet.com/wu/images/rapid-prototyping/sls.pnghttp://www.custompartnet.com/wu/images/rapid-prototyping/sls.png

15. Fused Deposition Modelling • Works similar to inkjet printer • A polymer wire is used as base material. • Wire is melted and is sprayed from hot nozzle to create one layer of material. • Once this layer hardens, another coat is sprayed and process is repeated. http://en.wikipedia.org/wiki/Fused_deposition_modeling

16. Laminated object manufacturing • Base material is in the form of rolled sheets with adhesive material on its surface. • This sheet is feed through rollers. • A C02 laser is used to cut 1 layer at a time. • The cut portion adheres and rest is scrapped off thus creating required image. • Many such images stacked up form object.

17. http://www.custompartnet.com/wu/images/rapid-prototyping/lom.pnghttp://www.custompartnet.com/wu/images/rapid-prototyping/lom.png

18. Samples

19. Applications • Used for better visualization of product, sales and marketing presentations. • To make machine tools. • patterns for intrinsic shapes. • To test part before final manufacturing. • Manufacturing of certain products like lenses. • Used in aerospace, biomedical, engineering models manufacturing.

20. Advantages • Is quicker than actual machining of product, saves time • Suitable for low volume production • It enhances product development

21. Summary • Rapid prototyping is a fast and accurate method of manufacturing • Through proper software and hardware application is very easy • Complex and difficult to machine shapes can be manufactured quickly • There are various methods for prototyping, selection is made depending on the requirement • This method is gaining popularity in varied fields

22. References • http://www.efunda.com/processes/rapid_prototyping/intro.cfm • http://www.3dprototype.com/needtoknow.html • http://en.wikipedia.org/wiki/Fused_deposition_modeling • Pandey, P.M., Reddy, N.V., Dhande, S.G. Rapid Prototyping technology, applications and planning, International Journal of Machine Tools and Manufacture,2003. • Yan Yongnian , Li Shengjie ,Rapid Prototyping and Manufacturing Technology: Principle, Representative Techniques, Applications, and Development Trends. Tsinghua science and technology journal ISSN 1007-0214, volume 14, June 2009

23. Image sources • http://sites.psu.edu/engineeringdesign100/2012/03/06/rapid-prototyping/ • http://www.quickembed.com/Tools/Shop/UploadPhotos/201209/20120913122209104.jpg • http://d1949180.i149.quadrahosting.com.au/images_for_use/667_79_full.jpg • http://www.teufel-prototypen.de/images/stories/dienstleistungen/sls.jpg • http://3d-cam.com/images/product_pages/sla.jpg • http://www.quickparts.com/UserFiles/Image/IMG_9238.JPG

24. Thank you