The Rapid Prototyping Glossary

Learn the terms used in the rapid prototyping industry and their definitions in our rapid prototyping glossary. This is not an exhaustive list of all RP terms, it's simply a rapid prototyping glossary of the most commonly used terms.

Bridge Tooling Using rapid tooling for short-run injection molding with spec material until the production tool is ready for use.

Computer Aided Design (CAD) A process where computer software allows assistance in the design process.

Computer Aided Engineering (CAE) A process whereby computer software allows assistance in process of engineering.

Computer Aided Manufacturing (CAM) A process whereby computer-operated machines assist in the manufacturing process.

Computer Numerical Control (CNC) When a machine has its own independent computer control unit.

Core and Cavity These are the two parts of a mold. When the core and the cavity are combined, the shape of the mold is formed. This can then be filled with many types of materials to make a variety of parts.

Die Casting This is the process of using metal instead of plastic in an injection molding setup.

Direct Numerical Control (DNC) When several CNC machines are controlled by a central computer. The DNC system generally controls drafting, machining, inspection, inventory control and other functions from a single computer. The programs are downloaded directly to the machine's control from the central computer.

Durometer A method of measuring the hardness of plastics, synthetics and natural rubber materials. When citing a hardness reading, please be careful to indicate which method and which scale is being used.

E-mail This is a form of data transferring. Data is transferred from one address to another electronically through cyberspace, over a long path of detours.

File Transfer Protocol (FTP) This is a safe and secure way to send a file from one data port to another. This method of data transferring allows both the sender and the receiver to acknowledge the transfer. It is like a cyberspace handshake.

Fused Deposition Modeling Process (FDM) Thermoplastic modeling material is fed into the temperature-controlled FDM extrusion head and heated to a liquid state. The head extrudes and deposits the material in ultra thin layers onto a fixtureless base.

Investment Casting Also known as the "lost wax method." This is a process where a wax part is repeatedly dipped with layers of ceramic material slurry. After many layers are applied, the entire part is baked at a very high temperature. The high temperature hardens the layers and melts out the wax, leaving a mold ready for casting. The metals most commonly cast are aluminum, steel, zinc and magnesium.

Keltool A proprietary process developed by 3D Systems in rapid tooling for injection molding. A metal powder/binder mixture is poured around a positive silicone RTV submaster. Once the binder sets to form and holds the part, it is sintered at a high temperature. This allows the binder to be replaced and impregnated, typically, by copper.

Laminated Object Manufacturing (LOM) A laser cuts the outline of a cross section of the CAD file into an ultra thin layer of modeling material. A new layer of material is then indexed, bonded to the previous layers, and cut. This process is repeated using very thin layers of material.

Pro Engineering (PRO E) Engineering concept modeling software that allows product designers to generate their ideas in 3D. This is a licensed product from Parametric Technologies.

QuickCast An SLA build style that produces a thin shell with a honeycombed interior. This method is used mostly for investment castings when the SLA model will be used as a sacrificial mold.

Rapid Prototyping "Fabrication of a physical, three-dimensional part of arbitrary shape directly from a numerical description (typically a CAD model) by a quick, highly automated and totally flexible process." Rapid Prototyping Report, October 1992

"A term used to describe a three-dimensional output technology that can make rapid reproductions of human error, perfectly." "A definition of 'Xerox'" by Merle L. Meacham

RTV Molding A procedure whereby a part is molded in a silicone surrounding to reproduce up to twenty urethane parts that are specified to color and property. The casting material can be urethanes of various properties, rubber or wax.

Selective Laser Sintering (SLS) A laser traces the shape of the part to be modeled in a thin layer of powder. The laser sinters (softens and bonds) the powder particles together. This process is repeated over layers of powder.

Shore A The Shore A scale is most commonly used as a measurement for the more "rubber-like" materials, including most silicone RTV materials. (Silicone rubbers generally run between 20 and 60 on the Shore A scale.)

Shore D The Shore D scale measures harder elastometric products. Both Shore A and Shore D scales measure hardness on a table from 0 to 100. The higher the measured value, the harder the material. Ratings are always qualified to plus or minus five points due to variations of test results from operator to operator.

Stereolithography Selective curing of a photopolymer resin by an ultraviolet laser, built on a descending platform, in a vat.

Structure Dynamics Resource Corporation (SDRC) Another type of engineering concept modeling software that allows engineers to design products in 3D.