Rapid prototyping is the construction of parts and models inside a machine that continuously adds layers over time, a process called additive manufacturing. Sometimes the process can be used to make parts that are suitable for production. The different types of rapid prototype machines usually depend on Computer Aided Design (CAD) software so that they can produce a copy of an animated computer model, for example, often in a few hours. A stereolithography system is a form of rapid prototyping machine, while others are based on selective laser sintering, fused deposition modeling, and laminated object manufacturing. Three-dimensional printers are often used as well to produce parts.
One system used for prototype production is the stereolithography machine. A liquid plastic called a photopolymer is usually contained within these rapid prototype machines, while a hole-filled platform can move up and down within the tank. During the printing process, the medium is typically exposed to an ultraviolet laser, which hardens the plastic one layer of time. All of the machine’s functions are generally controlled by a computer.
Rapid prototype machines that use selective laser sintering are often part of manufacturing processes as well. These include a powerful laser, which often pulses, that can fuse materials such as plastic or metal one layer at a time. Each layer is generally based on a cross-section of a computer representation of a part. The materials, typically in powder form, are usually exposed to a laser as a platform is lowered through the machine.
With fused deposition modeling, plastic can be dispensed through a device that moves according to the shape of each layer of an object. The mechanism is often similar to a hot glue gun and a machine head that can move in different directions. Rapid prototype machines used for laminated object manufacturing often include plastic, paper, or metal as the production material. The material is fed into the machine and a carbon dioxide laser is often used to cut each piece into a cross-section of a part.
Three-dimensional printers are often seen in offices, schools, laboratories, and manufacturing facilities. Companies using CAD data for any purpose can benefit from these kinds of rapid prototype machines. Some of these print in monochrome while others are able to produce models in full color. They can use a variety of materials, depending on the machine, and often connect to common computer systems and software programs.