A company called Klock Werks in Mitchell, S.D. (kustomcycles.com), provides one-of-a kind covers, housings, pans, and brackets for customizing bikes. The shop uses a Prodigy Plus FDM rapid-prototyping (RP) machine from Stratasys Inc. in Eden Prairie, Minn. (stratasys.com), to build or "print" the parts directly from 3D CAD models.

"The parts give customers a subtle way to make their bikes stand out," says shop partner Brian Klock. "We've used the RP machine to fabricate components ranging from a complete gage housing to hold a tach, shift light, and speedometer to a simple cover for what is called the triple tree, the area where the handle bars attach. Triple trees are cast parts and less than aesthetically pleasing. We used the RP machine to make nice, smooth covers for the area."

Klock says the shop got serious about RP when it participated in a Discovery Channel biker build-off. "We already had the frame, wheels, tires, and gas tank, but we 3D-printed the other parts," says Klock. The Prodigy let us easily and quickly fabricate new designs to get the motorcycle from a pile of pieces to a painted vehicle going down the road and looking good, all within 10 days."

Klock Werks could not afford the time or expense of machining one or two-piece runs, even for simple parts. The shop continues to build parts on the RP machine from ABS or polycarbonate until they become widely used and demand rises. "These materials can be sanded and painted and are strong enough to withstand vibrations from the motorcycle. One of our bikes recently set a land-speed record of 147 mph. Parts built using RP are still on the bike," says Klock.

The RP parts are functional as well as aesthetic. "For example, we built a mount to hold the headlights, which weigh probably 2 to 3 lb each. The headlights have a retainer ring that sandwiches them with a front bezel plate. We also printed those parts," Klock says.

It takes the shop a few hours to build a 0.050-in.-diameter part, while a floor board pan can go to 18 hr. The rapid-prototyping material comes in a variety of colors for mock-up purposes. But most shop customers want a show finish, so the company sands, primes, and paints parts.