Created by unseen hands

Meet the site that uses innovative fabrication technology to 'grow' parts to exact specifications

BY KATHRINE BECK

A new technology is making it possible to watch parts literally build themselves—exactly according to design drawings.

When an Asian carrier arranged for a redesign of its 777 interiors from an outside firm, one of the new design elements was a foot-level lighting fixture, similar to those in a cinema aisle, to make it easier to walk around the cabin in the dark. The widebody Lighting Development group in Everett, Wash., had to engineer a stainless steel part that would hold the light's lens in place.

The design firm's vision called for a complex shape, recalled engineer Nicole Miller. Adding to this challenge: The production run was for just 19 airplanes, and the parts were needed quickly. Miller's group consulted Mark Negley, Phantom Works material and process engineer, who came up with the solution. He told them about the Rapid Prototype Manufacturing organization at the Puget Sound Developmental Center, part of the Commercial Airplanes Engineering and Manufacturing organization.

The RPM lab owns one of four EOS M270 direct metal deposition machines in North America. It can build a part layer-by-ultra-thin-layer from stainless steel powder by using a computer-guided laser operating in a glassed-in nitrogen environment. The technical term for the process is sintering—getting particles to coalesce into a solid mass under the influence of heat without liquefaction. The EOS M270 builds the part by using a solid-model data file derived from computer-aided design (CAD) drawings of the part.

Russ Martiens, the project engineer on the EOS M270, is responsible for the lighting part having become the first production part in sintered metal on an FAA-certified aircraft. Watching the manufacturing process through the glass is like seeing something created by unseen hands. The laser dances spectacularly across a metal plate like a Fourth of July sparkler, heating just the portions of powder needed to form the object. When the parts are done, they are sawed off the metal plate, polished and trimmed.

This process demonstrates the capabilities of the RPM, which uses processes known as "additive technology" or "e-manufacturing" to build objects in a whole new way. If traditional fabrication techniques are about removing parts of a material to create an object, this technology is more like growing them.

"There's lots of potential for additive manufacturing technology to save money, decrease weight and reduce part count by combining several parts into one complex component," Negley said.

The same technology can be used to build titanium parts in a helium environment and aluminum parts in an argon gas environment. Les Tardiff, RPM manager, says if Boeing customers have a need for these capabilities, he'd be glad to add them.

RPM already has a variety of other e-manufacturing machines available. Its stereolithography machines build epoxy objects by tracing a laser beam on the surface of a vat of liquid photopolymer. The computer-guided laser beam turns the liquid to solid in places where the object needs to be formed. After a layer of about 1/5000th of an inch is finished, the growing part is automatically lowered a small distance into the vat, coating it with a fresh film of resin, and a second layer is traced right on top of the first. The layers form the complete, three-dimensional object.

Not only can e-manufacturing equipment create objects from data files, it also can reverse engineer—scanning an object and developing the electronic data files to program a machine to make a clone.

Besides making parts and test and display models for Commercial Airplanes customers, RPM also provides its expertise and production capability to other business units.

Said Tardiff: "We can save customers all kinds of time and money because we can do it quickly and cheaply, sometimes overnight."

kathrine.k.beck@boeing.com