Introduction to Rapid Prototyping

Introduction to Rapid Prototyping

• Rapid prototyping (RP) is a class of technologies that create physical models from Computer-Aided Design (CAD) data.
• Alternative names for RP include Additive Manufacturing, Layer Manufacturing, Direct CAD Manufacturing, and Solid Freeform Fabrication.

Traditional Prototyping vs. Rapid Prototyping

• Traditional prototyping involves building a model from clay, carving from wood, bending wire, or using thermoplastic, photopolymer, metals, paper, or titanium alloys.
• Traditional prototyping methods are time-consuming, lack quality, and cannot effectively evaluate alternative design concepts.
• Rapid prototyping methods are faster, more accurate, and can effectively evaluate design concepts.

Classification of Rapid Prototyping Systems

• RP systems can be classified into three categories: liquid-based, solid-based, and powder-based.

Liquid-Based RP Systems

• Liquid-based RP systems include:
  • 3D Systems' Stereo lithography Apparatus (SLA)
  • Cubital's Solid Ground Curing (SGC)
  • Sony's Solid Creation System (SCS)
  • CMET's Solid Object Ultraviolet-Laser Printer (SOUP)
  • Autostrade's E-Darts
  • Teijin Seiki's Soliform System
  • Meiko's Rapid Prototyping System for the Jewelry Industry
  • Denken's SLP
  • Mitsui's COLAMM
  • Fockele & Schwarze's LMS
  • Light Sculpting
  • Aaroflex
  • Rapid Freeze
  • Two Laser Beams
  • Micro fabrication

Additive Manufacturing Techniques

• 1. Laser Engineered Net Shaping (LENS)
  • Builds components in an additive manner from powdered metals using a Nd:YAG laser.
  • Produces fully dense metal parts with good metallurgical properties.
  • Advantages: superior material properties, complex parts, and reduced post-processing requirements.
  • Disadvantages: limited materials, large physical unit size, and high power consumption.
• 2. Direct Metal Deposition (DMD)
  • Uses a laser to weld air-blown streams of metallic powders into custom parts.
  • Can produce fully dense metal parts with good metallurgical properties.
  • Advantages: ability to fabricate fully dense metal parts, efficient, and reduces production costs.
  • Disadvantages: limited to building overhang parts and requires support structures.
• 3. Sheet Lamination (Laminated Object Manufacturing (LOM)
  • Builds parts by laminating layers of paper or other materials.
  • Advantages: fast, inexpensive, and ideal for patterns for casting.
  • Limitations: grid cutting takes time, decubing is time-consuming, and horizontal surfaces pose problems.
• 4. 3D Printing
  • Similar to SLS, except that a binder liquid is sprayed in selected regions.
  • Can use a wide variety of powders.
  • Advantages: fast, inexpensive, and ideal for concept models.
  • Limitations: requires sintering, and supports are required.
• 5. Fused Deposition Modeling (FDM)
  • Uses molten material to build parts.
  • Advantages: uses any thermoplastic material, easy to remove support, and inexpensive.
  • Limitations: slow, not very accurate, and requires explicit support structures.
• 6. Electron Beam Melting (EBM)
  • Uses an electron beam to induce fusion between metal powder particles.
  • Advantages: fast, efficient, and can process conductive materials.
  • Limitations: can only be used with conductive materials, and has a larger heat-affected zone.
• 7. Selective Laser Sintering (SLS)
  • Uses a laser to fuse together metal powder particles.
  • Advantages: fast, uses a wide variety of powders, and ideal for making injection molding tools.
  • Limitations: surface finish is poor, and Z accuracy is poor.
• 9. Photopolymerization (Stereo Lithography (SLA)
  • Uses a laser to polymerize liquid photopolymer.
  • Advantages: fast, accurate, and ideal for making prototypes.
  • Limitations: requires explicit support structures, and post-processing is required.

Learn about Rapid Prototyping (RP), a technology that creates physical models from CAD data, and its differences with traditional prototyping methods.