Prototyping Options

When constructing a prototype to evaluate the functionality of a product, there are many options. The following are some of the most common.

Digital Prototypes

Although one often thinks of a prototype as something physical you can hold in your hand, the state of technology in computer aided design (CAD) and computers is allowing an increased capability in modeling the real world behavior of a part or assembly of parts. While some amount of digital prototyping will usually occur in the design process, additional analysis can often be performed to evaluate fit, interference, strength, and other multi-physical processes.

Rapid Prototypes

A “rapid prototype” is produced by a machine that can be thought of as a 3D printer, thus requiring a three dimensional model of the part to be constructed. Materials for this type of prototype are limited and tend to be somewhat fragile. These prototypes work well for demonstrative purposes, evaluation of fit, and, in some cases, function if the part does not support high loads.

Machined and Fabricated Prototypes

Plastic stock may be machined or welded by traditional methods. The advantage of this methodology is that the parts will have material properties close to those expected for the molded parts. One issue often encountered is availability of the desired resin in sheet, block, or rod form.

Molded Prototypes

In some cases it may be necessary to actually mold a part to evaluate its performance. If the project requires a production tool with multiple cavities and / or complicated features requiring slides or unscrewing components (to form internal threads), the decision may be made to construct a prototype mold. Such a tool may be made from less expensive materials, make use of hand loads, or omit some features that are machined into the part after molding. Depending on the specific construction, a prototype mold may be suitable for producing a few parts only or up to several thousand.