The rapid prototyping industry is evolving as quickly as the solid models they produce. Still in its infancy, rapid prototyping (RP) is only about 10 years old. But it has mushroomed to a $452 million industry worldwide, and its future looks bright.

RP machines produce physical models based on a 3D computer-generated design. Layer by layer, RP machines use liquid, powder and sheet materials to fabricate plastic, wood, ceramic and metal parts using thin horizontal cross sections from the computer model.

An RP model can be produced in a matter of hours, as opposed to days or weeks for conventional wood, clay or metal models. Automotive executives, eager to shave product development time, were among the first converts to RP.

Today, manufacturers are saving big money on RP, thanks to plummeting prices for units as well as at service bureaus, where manufacturers can rent time on RP machines to make their models.

Systems, which had cost up to $500,000, are now down to as low as $50,000.

And service bureau rates also have fallen dramatically - as much as 50% over two years, says Terry Wohlers, president of Wohlers Associates in Fort Collins, CO.

His company analyzes rapid product development, and recently released its 208-page report on the state of the RP industry worldwide.

In 1992, Mr. Wohlers estimates it cost $1,500 or more to produce a small part on an RP machine at a service bureau. Today, the price is down to less than $300 for a similar part. Prices have fallen as new players have joined the market and as lower-cost systems have arrived.

As a result, service bureaus are struggling to make money, and some have closed.

Falling prices at service bureaus, coupled with a drop in sales of high-priced systems, have restricted the revenue growth of the RP industry. In 1997, money spent in the industry grew by only 7%, compared to 42% in 1996, the report says.

Still, unit sales have been growing since 1991, when the young industry reported sales of 82 units. In 1997, Mr. Wohlers reports, RP unit sales worldwide peaked at 1,057, a 34% increase over 1996.

A new player making a splash is Z Corp. of Somerville, MA, whose new Z402 3D Printer costs only $59,000 and can build a part in 60 minutes. Mr. Wohlers says by 2003 an RP machine, in the form of a 3D printer, may cost as little as $10,000. Years later, systems could be available, he adds, for $2,000 or less.

The auto industry is likely to continue its migration toward rapid prototyping, Mr. Wohlers says. He points to General Motors Corp., which has a new RP facility at its technical center in Warren, MI.

"Automotive is really pushing the envelope with RP," he says. An advantage of transparent RP models is that they allow engineers to analyze the flow of air and fluids through them in developing ventilation and engine systems.

Automakers also are pushing their suppliers to use simulation software, a similar product that allows virtual prototypes of vehicle systems to be fully tested before assembly.

Analogy Inc. of Beaverton, OR, a supplier of simulation software used to test virtual prototypes of automotive electronic and electromechanical systems, has been steadily growing since opening shop in 1985. The company estimates automakers can save up to $1.5 million for every day cut from the product development process.

"Automotive will be a major growth area for us for the foreseeable future," says Kenneth Waichunas, director of central operations-North America for Analogy. "The OEMs want to reduce costs, get the design right, minimize recalls, make the products more robust and increase quality. The only way to do it is through virtual prototyping."

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