Quick prototyping technologies review.

Rapid prototyping takes virtual designs from CAD or animation modeling software, transforms them into thin, virtual, horizontal lateral sections and then creates each cross sections in physical space, one after the next until the model is finished.It is a WYSIWYG process where the virtual model and the physical model correspond almost identically.With additive fabrication, the machine reads in data from a CAD drawing and lays down successive layers of liquid, powder or sheet material, and in this way builds the model from a series of cross-sections.These layers, which correspond to the virtual lateral sections from the computer aided design model, are joined together or melted automatically to create the final shape.The primary advantage to Rapid fabrication is its ability to create almost any shape or geometric feature.The standard data interface between computer aided design (CAD) software and the machines is the STL file format.An STL file approximates the shape of a part or assembly using triangular facets Smaller facets produce a higher quality surface.Read more: Rapid manufacturing

The word "Rapid" is relative: construction of a model with contemporary methods can take from several hours to several days, depending on the method used and the size and complexity of the model.Additive systems for Rapid prototyping can typically produce models in a few hours, although it can vary widely depending on the type of machine being used and the size and number of models being produced simultaneously.

Some solid freeform fabrication techniques use two materials in the course of constructing parts.The first material is the part material and the second is the support material (to support overhanging features during construction).The supporting material is later removed by heat or dissolved away with a solvent or water.Traditional injection moulding can be less expensive for building polymer products in high quantities, but additive fabrication can be faster and less expensive when producing relatively small quantities of parts.Rapid prototyping is now entering the field of Rapid building-up 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.Some are liquating or softening material to produce the layers (SLS, FDM) where others are laying liquid materials thermosets, which are cured with different technologies.In the case of lamination systems, thin layers are cut to shape and joined together.As of 2005, conventional Rapid prototype machines cost around 25, 000 pounds sterling.Prototyping technologies Base materials: - Fused deposition modeling (FDM) - Selective laser sintering (SLS) - Stereolithography (SLA) - photopolymer - Laminated object manufacturing (LOM) - 3D printing (3DP) - Electron beam melting (EBM)