Once upon a time a prototype was a model of the real thing. Now, as prototype engineers, we are expected to produce prototypes that not only look just like the real thing, but function like them too.

Nowhere is this truer than in the electronics sector, where clients need to show buyers or investors something as close to the real thing as possible. The development of new processes and materials makes this realism possible and what would once have taken three to four days can now be done in three to four hours.

How the prototype is produced depends on the number – anything from a giant sized one-off for an exhibition to a small production run of up to 500 can be dealt with using a range of processes, including rapid prototyping machines, Polyjet, vacuum casting, advanced materials and CAD/CAM.

Product designer Rick Dickinson of Dickinson Associates believes what is expected from model makers can be unrealistic.

“The demands on model making and prototyping are constantly increasing and clients and end users have extremely high expectations of what is achievable,” says Dickinson. “There are demands on time, functionality and cosmetics. And much of a product’s functionality and cosmetic finish is reliant entirely on mass production processes, especially with increasing mechanical integration and miniaturisation.”

According to Ian Murphy of electronic design firm Plextek, this striving for perfection in prototypes can have its disadvantages. “Design teams can be pressurised into committing to an industrial design so that a model can be made that has not yet had sufficient development of the electronics to prove that the key components can fit and will work in the positions allocated to the industrial designer,” explains Murphy.

“This usually has the effect of a product needing to grow during the development cycle or compromises being made that are to the detriment of the final product performance, for example, antenna size and position relative to other electronic circuitry.”

To avoid costly mistakes clients need to go to the prototype engineers/model makers as early in the process as possible. They can identify the best type of rapid prototyping to achieve the best results in the most cost effective way.

If they are likely to want to make changes a flexible prototype can be produced, while a one-off will be produced differently than a small production run.

The model makers can also sort out potential problems, such as producing a prototype for an exhibition that is fully working, but with the electronics operated by a laptop out of sight. Potential problems can also be picked up, such as in the production of a speaker prototype when a manufacturing problem was identified that could then be solved.

Prototyping specialist Complete Fabrication recently created the prototypes for a handheld GPS and gaming device designed by Dickinson Associates.

The product was to be demonstrated at shows months before it was to be manufactured and they wanted 60 prototypes produced, each one with a different finish.

For the designers of the electronics, Plextek, this meant designing electronics with limited capability. “The terminal has a high level of electronics content which meant that compromises had to be made between the electrical performance and aesthetics,” states Murphy. “If the prototype was to do its job it needed not only to aesthetically represent the finished product but to be mechanically robust and give the same feel as the final product.”

To achieve this a master was made using a Polyjet machine and from this vacuum castings were made that could take many different surface treatments and colour combinations.

Some clients are taking the prototype idea one step further by using the same processes to produce the finished product. Companies making products with small production runs - from five to 200 units – are now using rapid prototyping as a faster way of producing a quality product.

If a company’s product run is too small to justify injection moulding, rapid prototyping can bring the same quality for a lot less money. In the past, where a small number of units were being produced, an off-the-shelf or bent metal box would have been used. Now parts that look like bespoke injection moulding can be made, but without the associated tooling costs. This is definitely a growth area.

So the definition of prototyping is definitely changing as the electronics industry tries to keep one step ahead of the competition and get its products out to market first. But as Dickinson points out, there are some parts of this process that cannot change.

“As much as I’m constantly amazed by the results of the model making machinery and technology, what still impresses me the most are the foundations to this – the more human hand-based skills,” states Dickinson. “The art in predicting what will work and what will not; meticulous model planning; fanatical levels of precision and detailing with scalpels and brushwork beneath microscopes; a feel for materials, surface finishes, ways around problems and disasters and the unexpected. When a model is finished it is a work of art.”

Dave Kent is managing director of Complete Fabrication