1. RAPID PROTOTYPING

2. Rapid Prototyping (RP) is a technique for direct conversion of three dimensional CAD data into a physical prototype.
RP allows for automatic construction of physical models and has been used to significantly reduce the time for the product development cycle and to improve the final quality of the designed product.

3. Advantages of rapid prototyping
Builds complex 3D geometrical shapes
Is automated based on CAD models
Uses a generic fabrication machine that does not require part specific tooling
Requires a minimum of or no human intervention
Produces accurate prototypes in a short time at a minimum cost

4. Prototyping Technologies
Base Materials
Selective Laser Sintering (SLS)
Thermoplastics, metal powders
Fused Deposition Modeling (FDM)
Thermoplastics, eutectic metals
Stereolithography (SLA)
Photopolymer
Laminated Object Manufacturing (LOM)
Paper
3D Printing (3DP)
Various materials

5. Classification of RP techniques
1. Liquid-based techniques
2. Powder-based techniques
3. Solid-based processes

6. Selective Laser Sintering (SLS)

7. Advantages of SLS
• It produces the toughest components compared to other RP techniques.
• A wide range of materials can be used, including metal, plastic, ceramics, wax, nylon, elastomers
• A relatively short production time (approximately 1 in/h) is possible.
• No post curing processes are needed.
• No additional support is required during the building process.
• Leftover powder can be reused.
• Different parts can be built right on top of others.

8. Disadvantages of SLS
• A rough surface finish is produced due to the stair-step effect.
• The time needed to heat up the powder and cool down the model after it has been completed is approximately 8 to 10 h.
• Toxic gases are produced especially when plastic materials are fused.
• Components are less detailed than those produced by stereolithography due to a high processing temperature and high shrinkage.

9. Fused Deposition Modeling

11. Advantages of FDM
Quiet, nontoxic, and office-friendly process
Fast for small, thin shapes
Produces strong parts
Cost-effective
No need for part cleanup
Able to produce multicolored parts using colored ABS

12. Disadvantages of FDM
Slow when making large cross-sectional areas
Has to use additional support material
Relatively low accuracy and poor surface finish
Unable to make complicated parts
Limited number of materials available

13. Stereolithography

15. ADVANTAGES
• High and better dimensional accuracy when compared with other RP techniques.
• Unattended system
LIMITATIONS
• The technique requires support structure.
• The components can get warped.
• Resin is expensive.
• Resins and solvents can be environmentally hazardous.

16. 3D Printing

17. Laminated Object Manufacturing