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Laser tracks aircraft parts

Nov. 1, 2003
COAST COMPOSITES INC. OF IRVINE, CALIF., MAKES forming tools (molds and mandrels) for large composite aircraft parts. These include skin and fuselage sections, stabilizers, and nacelles for both commercial and military aircraft. Because of where they are

Coast Composites measures its forming tools (molds and mandrels) for large composite aircraft parts with a Faro Laser Tracker. Most conventional inspection systems can't readily accommodate such big parts.

COAST COMPOSITES INC. OF IRVINE, CALIF., MAKES forming tools (molds and mandrels) for large composite aircraft parts. These include skin and fuselage sections, stabilizers, and nacelles for both commercial and military aircraft. Because of where they are used, tolerances on these parts have to be as close as ±0.010 in. on contours and ±0.003 in. on holes. The problem in holding these tolerances is the part size. An upper wing skin for the new JSF multi-role fighter, for instance, is 53-ft long, while a stabilizer part for a military transport measures 45 ft. Conventional inspection systems cannot readily accommodate such mammoth sizes, so Coast uses a Faro Laser Tracker.

According to Jerry Anthony, CEO of Coast, the largepart measuring device is simple to operate and collects hundreds of data points within minutes of setup. To use the system, an operator places the Tracker base on a tripod and takes measurements by touching or dragging a target reflector along the surface to be measured. The reflector then bounces beams back to the base unit.

If the beam between the Tracker and target is interrupted, the system's SuperADM feature lets it reacquire the beam without returning to a reference point. The measuring envelope of this system ranges from ±360° horizontal to +80°/50° vertical. Point accuracy is 10 µ +0.8 µ.

Using the angle between the beams and the distance to the target, software within the Tracker triangulates and records the position of each point within its 230-ft range. The sending/receiving unit mounts in any position and works in environments from factory floors to virtually any remote operation.

Coast adds a new wrinkle to the versatility of the Tracker by making it wireless. Through an antenna on the base unit, a 3D model travels directly to the Tracker's controlling computer. Measurement data and subsequent data analysis return wirelessly to the company's central file server, which is accessible to authorized personnel.

From the very beginning of its mold/tool development process, Coast incorporates the Tracker and sometimes expands its role by using it as a positioning device.

"Our molds/tools tend to be large and expensive to build because we use a lot of Invar to make them," explains Anthony. "Invar is a high-nickel-bearing ferrous alloy with a near-zero coefficient of thermal expansion, which makes it ideal for exothermic molding of carbon-fiber-composite parts. But it carries a high price tag and a reputation for being difficult to machine. As such, we cannot afford errors and rework. By giving us extremely precise specifications, the Tracker enables us to eliminate errors and get the molds made right the first time."

Faro Technologies
LAKE MARY, FLA.
faro.com