1. RAPID PROTOTYPING
REVISION

2. Rapid prototyping is the automatic construction of physical objects using solid freeform fabrication. The first techniques for rapid prototyping became available in the late 1980s and were used to produce models and prototype parts. Today, they are used for a much wider range of applications and are even used to manufacture production quality parts in relatively small numbers.
Rapid prototyping is now entering the field of rapid manufacturing and it is believed by many experts that this is a "next level" technology.
A large number of competing technologies are available in the marketplace. As all are additive technologies, their main differences are found in the way layers are built to create parts.

4. Selective laser sintering
Selective laser sintering is an additive rapid manufacturing technique that uses a high power LASER to fuse small particles of plastic, metal, ceramic, or glass powders into a mass representing a desired 3-dimensional object.
After each cross-section is scanned, the powder bed is lowered by one layer thickness, a new layer of material is applied on top, and the process is repeated until the part is completed.

5. Fused deposition modelling
Fused deposition modelling, is often referred to by its initials FDM. It works on an "additive" principle by laying down material in layers. A plastic filament or metal wire is unwound from a coil and supplies material to an extrusion nozzle which can turn on and off the flow.
In 2006, FDM was the best-selling rapid prototyping technology

6. Stereo lithography
This is a common rapid prototyping technology for producing parts with high accuracy and good surface finish.
A device that performs stereo lithography is called an SLA.
Stereo lithography is an additive fabrication process utilizing a vat of liquid UV-curable photopolymer "resin" and a UV laser to build parts a layer at a time.
After a pattern has been traced with the laser, the SLA's elevator platform descends by a single layer thickness, typically 0.05 mm to 0.15 mm.
Then, a resin-filled blade sweeps across the part cross section, re-coating it with fresh material.
An SLA machine can cost from $100,000 to $400,000 – VERY EXPENSIVE!

7. Laminated object manufacturing
Laminated object manufacturing (LOM) is more simple rapid prototyping system. In it, layers of adhesive-coated paper, plastic, or metal laminates are successively glued together and cut to shape with a knife or laser cutter.
Low cost due to readily available raw material
Paper models have wood like characteristics, and may be worked and finished accordingly
Dimensional accuracy is slightly less than that of Stereolithography and Selective laser sintering.
Relatively large parts may be made, because no chemical reaction is necessary.

8. Electron beam melting
Electron beam melting (EBM) is a type of additive manufacturing for metal parts. It is often classified as a rapid manufacturing method. The technology manufactures parts by melting metal powder layer per layer with an electron beam in a high vacuum. Unlike some metal sintering techniques, the parts are fully dense, void-free, and extremely strong.
Titanium alloys are widely used with this technology which makes it a suitable choice for the medical implant market.

9. 3D printing 3D printing usually consists of an inkjet printing system.
Layers of a fine powder (plaster, corn starch, or resins) are selectively bonded by "printing" an adhesive from the inkjet print head in the shape of each cross-section as determined by a CAD file.
This technology is the only one that allows for the printing of full colour prototypes. It is also recognized as the fastest method.