Rapid prototyping

Encyclopedia : R : RA : RAP : Rapid prototyping

Rapid prototyping also describes a software engineering methodology.

One technique for rapid prototyping uses a 3D printer like this one.

Rapid prototyping, is the automatic construction of physical objects using solid freeform fabrication. The first techniques for rapid prototyping became available in the 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 art exhibitions.

In brief, rapid prototyping takes virtual designs (from computer aided design (CAD) or from animation modeling software), transforms them into cross sections, still virtual, and then create 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.

In additive fabrication, the machine reads in data from a CAD drawing, and lays down successive layers of liquid or powdered material, and in this way builds up the model from a long series of cross sections. These layers which correspond to the virtual cross section from the CAD model are glued together or fused (often using a laser) automatically to create the final shape. The primary advantage to additive construction is its ability to create almost any geometry (excluding trapped negative volumes).

The standard interface between CAD software and rapid prototyping machines is the STL file format.

The word "rapid" is relative: construction of a model with contemporary machines typically takes 3 to 72 hours, depending on machine type and model size. Used in micro technologies "rapid" is correct, the products made are ready very fast and the machines can build the parts in parallel.

Advances in technology allow the machine to use multiple materials in the construction of objects. This is important because it can use one material with a high melting point for the finished product, and another material with a low melting point as filler, to separate individual moving parts within the model. After the model is completed, it is heated to the point where the undesired material melts away, and what is left is a functional plastic machine. Although traditional injection molding is still cheaper for manufacturing plastic products, soon rapid prototyping may be used to produce finished goods in a single step.

Due to the high degree of flexibility and adaptability required by many rapid prototyping techniques, these applications typically require the use of robots or similar mechanisms.

However, there are currently several schemes to improve rapid prototyper technology to the stage where a prototyper can manufacture its own component parts (see RepRap Project). The idea behind this is that a new machine could be assembled relatively cheaply from raw materials by the owner of an existing one. Such crude 'self-replication' techniques could considerably reduce the cost of prototyping machines in the future, and hence any objects they are capable of manufacturing.

References

• Grenda, E. (2006). [The Most Important Commercial Rapid Prototyping Technologies at a Glance].
• Wright, Paul K. (2001). 21st Century manufacturing. New Jersey: Prentice-Hall Inc.

See also

• Configuration System
• Toolkits for User Innovation

External links

• [Solid Freeform Fabrication] Laboratory at University of Texas at Austin
• [Technical Articles] on additive processes from consultancy firm Wohlers Associates
• [Self-Replicating Rapid Prototypers] at the University of Bath
• [Overview of Rapid Prototyping technologies] including technologies, applications, materials and tools by Paramount Industries
• Rapid Prototyping tools: [How to Create an STL file] and [Free STL Viewer download] courtesy of ProtoCAM
• [Materials used in Rapid Prototyping], courtesy of RedEye RPM.
• [Rapid Prototyping Info] at GlobalSpec

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.