chrome plating, it is known to last up to three to five times longer than chrome.”
Components from the hot section of jet engines, in par-
ticular, need specialized coatings. “That’s where your thermal barriers come into play,” he said, “to protect precious metals, component alloy types, with a thermal spray coating to pre- vent heat from penetrating into the base metal, distorting or eroding the original substrate.”
“Aerospace production is a relatively slow,
low-volume, high-value process compared to other manufacturing. The ‘volume’ demand
is not the product throughput, but rather the high number of process steps required.”
SLM also does its own in-house nondestructive testing
(NDT) for detecting surface cracks or porosity on coated parts. “We’ve been using robots since the early 1980s, and we’ve built up our business on it,” said Desloge. “We standardized on ABB robots, because the quality is sky-high. Consistent quality is everything, and rework hurts your reputation.” Force sensing technology from Fanuc helped Aerobotix
Inc. (Madison, AL), an authorized Fanuc Robotics integra- tor, develop and commercialize its robotic sanding solution under the US Air Force Automated Sanding SBIR with the Air Force Research Laboratory for the F-35 program, said Aerobotix President and Owner Kirk McLauchlin. Now in Phase III SBIR status, Aerobotix offers the robotic sanding system to commercial and military customers. “It’s definitely applicable to other projects, and we’ve had multiple platforms that have shown interest in it,” McLauch- lin noted. “We’ve given demonstrations to just about every platform out there—from F/A-18, F-16, F-22 and B-2, as well as the F-35—just about anything where people spray LO [low- observable] coatings on an aircraft, there will almost always be some type of sanding required.”
Aerobotix, which was founded in 2005, started using Fa-
nuc’s force sensor around late 2008, McLauchlin said, noting the sensor previously had been employed mostly for automo- tive in assembly or grinding. “Just about everything we do is a nonstandard application of a standard product. As an integra- tor, our art is to take standard off-the-shelf products and put them together in a unique way to achieve a tool with specific
capabilities, then program it for use in advanced manufactur- ing processes,” McLauchlin said. “Fanuc would typically mount the force sensor to the
wrist of the robot and install an assembly tool or something similar on it. We remotely mount the sensor five to six feet from the wrist at the end of a long end-of-arm tool, because we have to reach into narrow, confined areas with the sander, so right away there are challenges in the program- ming and tuning.”
The Aerobotix system uses a Fanuc M-710 robot equipped with the R-30iA control platform and the Fanuc force sensor. “We can set the application force for the sanding tool to 5 kg and hold that, plus or minus 0.5 kg, which for a vibrating, shaking tool, is very good,” McLauchlin said. “Once you spray on low-observable coatings, it typically leaves a surface finish that’s not acceptable, like an orange peel, for the performance requirements of the coating.
“Between different coatings we may have to sand, just to knock off that rough finish, or there may also be areas where we have to do thickness sanding to remove material that’s put on too heavily. The final finish has to be uniform, so we use the sanding tool to smooth out the finish, and prepare it for proper adhesion of a final top coat application.” ME