Aircraft Technologies Inc. makes sinks, toilets and other assemblies for airframe manufacturers, completion centers, and maintenance and repair facilities. The company’s most popular externally serviced toilet, the Series 90, is made of thermoformed Kydex and composites that provide a high strength-to-weight ratio. Easy to install and service, the toilet flushes automatically when a user closes the cover.
In 2011, Aircraft Technologies began designing a new version of the Series 90 toilet. Its main parts include a bowl cap, spray ring and upper and lower bowl assembly.
For previous toilets, the company had designed all four parts from scratch and then built a new thermoforming tool for each part. However, Mark Riebesehl, owner and vice president of operations for Aircraft Technologies, was looking for ways to lessen design costs and development time.
Riebesehl decided the new design would feature an existing bowl cap and spray ring (from one of the company’s other toilets) joined to modified upper and lower bowl assemblies from another toilet. Unfortunately, because the assemblies were designed before the company started using CAD software, there was no model to modify.
This situation led Riebesehl to hire NVision Inc. and have its engineering service division laser scan the upper and lower bowl. Riebesehl and a co-worker flew to NVision’s facility in Dallas, watched the scanning and flew back with the scan data the same day. A short time later he received CAD surface models via an FTP site.
“We modified the CAD models to mate up with the existing bowl cap and spray ring,” says Riebesehl. “Then we generated CNC programs and built the tooling on a machining center. Everything fit together perfectly, validating the accuracy of the laser scanning process.”
Laser scanning works by projecting a line of laser light onto the surfaces to be measured while a camera continuously triangulates the changing distance and profile of the laser line as it sweeps along. A computer translates the video image of the line into accurate 3D coordinates of the object’s geometry. Engineers then create clouds (consisting of millions of points) and use the scan data to output the surface models.
“By scanning existing assemblies and modifying the models to fit parts that we already had tooling for, we only had to build two tools instead of four,” says Riebesehl. “This saved us about $20,000 in tooling costs and helped us get the new toilet into production four weeks earlier.”
Aircraft Technologies produces about 70 new Series 90 toilets per year for a corporate aircraft manufacturer. NVision has also helped other aircraft manufacturers, including Boeing, Lockheed, Lear and Raytheon. It has also done work for NASA and the U.S. military.
Double sealed to prevent leakage, the Series 90 toilet features a 0.75-inch wide waste dump line and a 0.5-inch flushing reservoir charge line. A macerator within the toilet breaks down waste and pumps it to a service cart outside the aircraft. The smaller line carries fresh flushing fluid to the reservoir from the cart.