6.3.4 What is rapid prototyping?

In general, rapid prototyping (RP) is defined as using a technological process to pro-duce 3D objects in a short period of time usually days rather than weeks. Most RP machines create 3D geometries by growing them layer-by-layer, but high-speed CNC machining a deductive process also meets these criteria in certain applications.1

The term rapid prototyping (RP) refers to a class of technologies that can automatically construct physical models from Computer-Aided Design (CAD) data. These "three dimensional printers" allow designers to quickly create tangible prototypes of their designs, rather than just two-dimensional pictures.2

Where can you use rapid prototyping?

Most rapid prototyping services are sold to the following industries: design & engineer-ing, R & D, consumer products, electronics, aerospace, automotive, robotics, appli-ances, telecommunications, orthopaedics, healthcare, dental, foundry, oil & gas, pet-rochemical, toys and plastics.

Such models have numerous uses. They make excellent visual aids for communicating ideas with co-workers or customers. In addition, prototypes can be used for design testing. For example, an aerospace engineer might mount a model airfoil in a wind tunnel to measure lift and drag forces. Designers have always utilised prototypes as RP allows them to be made faster and less expensively.

In addition to prototypes, RP techniques can also be used to make tooling (referred to as rapid tooling) and even productquality parts (rapid manufacturing). For small pro-duction runs and complicated objects, rapid prototyping is often the best manufacturing process available. Of course, "rapid" is a relative term. Most prototypes require from three to seventy-two hours to build, depending on the size and complexity of the object. This may seem slow, but it is much faster than the weeks or months required to make a prototype by traditional means such as machining. These dramatic time savings allow manufacturers to bring products to market faster and more cheaply.3 

Please stop and remember applications of Rapid Prototyping:

  • Visual aid for communication with co-workers
  • Visual aid for communication with customers
  • Design testing.

Have you ever used RP for these purposes? Would it suitable for your company and how could you manage the process?

Why rapid prototyping is important?

The rapid development of models or prototypes may largely reduce the development cost and the product development cycle. In 1994, Pratt & Whitney achieved "an order of magnitude [cost] reduction [and] time savings of 70 to 90 percent" by incorporating rapid prototyping into their investment casting process.4

In addition, they can be used in test markets prior to the entry of the product in the final production and commercialisation stage. Since it is based on technological changes or improvements, the development of such models or prototypes are usually conducted by technologists who have no regard for the cost of such a development. (The cost of such a development is due to the cost of the material, additional personnel, training of that personnel and system changes). The rapid development of models will be suc-cessful only if the following apply, and only then:

  • Each prototype should provide answers to specific questions
  • The prototype should be as detailed and complex as necessary to provide the required information
  • If there are multiple ideas, then it is necessary that multiple prototypes be de-veloped
  • Decisions should be made during the development of the prototype and one should not await its final form
  • The swifter the prototype development, the swifter the overall development of the new product. 5

1 Thomas, Jerry W.: Product Testing. 1993
2 William Palm (May 1998) Rapid Prototyping Primer:
3 lbid 
4 lbid 
5 InnoSupport: Supporting Innovations in SME. 6.2 Rapid Prototyping and Product Testing Strategies. 2005