Rapid prototyping
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Rapid prototyping takes a virtual 3D CAD model and builds a physical model layer by layer using materials like liquid, powder, or sheets. It can create almost any shape and is used for prototypes, models, production parts, and art. The process involves transforming the virtual design into cross sections, then creating each cross section physically with an additive fabrication machine by laying down successive layers that fuse together. While construction times can vary widely, additive systems can typically produce models in a few hours.
Rapid prototyping
- 1. http://injectionmoldingtechnology.com/rapidprototyping.htm Rapid Prototyping Also known as solid freeform fabrication, rapid prototyping is a technology that takes a virtual design (3D CAD models) and transforms the object into cross sections (layers). The RP software then creates each cross section laying down successive layers of liquid or other type of powdered material that will fuse together and solidify to create the final shape which represents an almost identical model.
- 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. Some sculptors use the technology to produce complex shapes for fine arts exhibitions. Rapid prototyping takes virtual designs from computer aided design (CAD) or animation modeling software, transforms them into thin horizontal cross sections, still virtual, and then creates each cross section 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 up the model from a series of cross sections. These layers, which correspond to the virtual cross section from the CAD model, are joined together or fused automatically to create the final shape. The primary advantage to additive fabrication is its ability to create almost any shape or geometric feature. The standard data interface between CAD software and the machines is the STL file format. An STL file approximates the shape of a part or assembly using triangular facets. Tiny facets produce a higher quality surface. 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 support material is later removed by heat or dissolved away with a solvent or water. Traditional injection molding can be less expensive for manufacturing plastic products in high quantities, but additive fabrication can be faster and less expensive when producing relatively small quantities of parts. 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 melting or softening material to produce the layers (SLS, FDM) where others are laying liquid materials thermosets that are cured with different technologies (SLA, MJM, PolyJet). In the case of lamination systems, thin layers are cut to shape and joined together.