New generation of rapid prototyping machines brings science fiction closer to reality.

Byline: Martin J. Moylan

They're certainly not as fast or versatile as Star Trek's "replicators," which, in a few seconds, could whip up anything from a glass of Romulan wine to a spare part for a warp drive.

But a new generation of rapid prototyping (RP) machines is bringing science fiction closer to reality.

The machines take three-dimensional computer designs and turn them into objects made in a variety of materials, including wax, metal, plastic and even chocolate, meticulously building them layer by layer.

To show off its new Titan rapid prototyping machine at a Cincinnati trade show last month, Eden Prairie, Minn.-based Stratasys had it turn out polycarbonate golf balls and invited attendees to give them a whack. The balls not only had enough zing to travel 250 yards but they were durable enough to dent several clubs.

"I see a day when companies will buy these in the 100s, instead of dozens," says Scott Crump, founder and CEO of Stratasys. "They'll be like printers. When they get down …