Composites Technology at F-35 Suppliers Conference

The attitudes observed at a recent F-35 Lightning II Joint Strike Fighter BMI Fiber Placement suppliers conference belied the mainstream media’s often gloomy reports about the advanced military program. The March event was the latest in a conference series hosted by MAG Americas, manufacturer of composites and machine tool equipment and systems, at its Hebron, Kentucky facility. The event brought together the F-35 program’s range of composites technology specialists—even competing parts producers—to share ideas in an effort to optimize efficiency and cost-effectiveness in support of the program.

 

The conference featured representatives of F-35 developer Lockheed Martin, including G.B. Bailey, a lead for manufacturing integration for the program. Wing and nacelle producers Alliant Techsystems (ATK) and Hitco Carbon Composites also participated, as did MAG composites customer ITT Exelis and material supplier Cytec Industries. Gardner Business Media, publisher of Modern Machine Shop, was the exclusive publishing company invited to attend the event.

 

Chip Storie, MAG’s executive vice president, says an open forum such as this, which included the introduction of new composites processing and milling equipment, will enable F-35 suppliers to price components more affordably for the overall betterment of the program. To that end, the conference’s highlighted piece of equipment was MAG’s new seven-axis BMI Viper fiber-placement machine, specifically designed for the tricky bismaleimide (BMI) prepreg material used to create critical F-35 wing and nacelle components. According to MAG, the new fiber-placement machine is said to offer significant improvement in lay-down rate from the first generation of BMI fiber-placement machines deployed for the F-35 program. The machine achieves nearly six times improvement in material lay-down rate compared to earlier generation equipment, with no fuzz generation.

 

MAG says this improved production rate is largely due to a better understanding of BMI’s unique processing requirements. Enhancements have been made to more accurately control the temperature of the material at the lay-down point, because too much heat causes it to become molten and viscous, virtually eliminating the material’s already minimal tack qualities. The configuration of all roller and guide systems has been modified, as well, and new component materials and coating are being used to help eliminate fuzz creation. In addition, the machine’s cut, clamp and restart (CCR) module can be disassembled, cleaned and reassembled without tools. This is said to reduce CCR maintenance from 6 minutes to 3 minutes. The BMI Viper platform was developed in collaboration with ATK, which will soon receive the second of its two machines. MAG plans to offer BMI retrofit packages for its existing installed base of Viper machines, too.

 

Mr. Bailey says what MAG is accomplishing with equipment such as the BMI Viper is just what the composites industry must have right now. “We need this type of improved productivity to become more cost-effective creating composites components for advanced aerospace applications,” he explains. “MAG is helping suppliers accomplish this especially with respect to the F-35 program. This is important because in the near future, the F-35 will be the only fighter aircraft the U.S. government will be purchasing.”

 

MAG composites machining systems were also highlighted at the conference. The Precision AutoDrill System applies technology from MAG plants in Fond du Lac, Wisconsin and Hebron. This system combines an FTR boring mill with an Autodrill ram, carrier and head. The machine seen in build will be delivered to Boeing’s South Carolina facility for drilling and trimming of 787 fuselage barrels. Combined with a rotary indexer, it will trim fuselage windows, doors and end connectors as well as drill more than 1,000 holes per barrel. It features an on-board toolchanger to change tools in 30 seconds no matter where the head is located along the machine’s 12-meter X-axis range. Plus, this is the first composites mill to be delivered with cryogenic, liquid-nitrogen through-tool-cooling technology.

 

The conference also featured two Precision Mill and Trim (PMT) gantry mills to be delivered to Triumph Aerostructures. These machines are said to be more robust than routers commonly used for composites trimming and more precise through use of scales on all five axes. In fact, the two machines at the conference will be used to trim and drill aluminum fuselage sections for Boeing 747 and 777 aircrafts. PMT mills can be outfitted for wet machining or dry machining when using a proprietary vacuum shroud and ducting design for effective dust control. To minimize energy consumption, the mills have only one hydraulic system, which is used to actuate the spindle drawbar.