Viper CNC fibre placement system for tiltrotor aircraft

Citation

(2000), "Viper CNC fibre placement system for tiltrotor aircraft", Aircraft Engineering and Aerospace Technology, Vol. 72 No. 1. https://doi.org/10.1108/aeat.2000.12772aab.006

Viper CNC fibre placement system for tiltrotor aircraft

Keywords Cincinnati Machine, Fibre, Helicopters

Cincinnati Machine reports that it has shipped the first compact model of its Viper CNC Fibre Placement System to US-based Bell Helicopter Textron. The Viper FPS-1200 will be used to automate construction of composite structures for the Bell 609, the civil tiltrotor aircraft.

Precision fibre placement is thought to serve four key improvement objectives for aerospace manufacturers, these being:

1. 1.

   costs;

2. 2.

   cycle times;

3. 3.

   structural weight; and

4. 4.

   handwork or reworking.

Automated fibre placement claims to provide cost and productivity advantages over traditional fabricated metal assemblies and hand lay-up of composites by allowing the production of monolithic one-piece structures in place of traditional multi-part assemblies. This is believed to reduce part count, assembly operations and overall purchasing and manufacturing logistics.

The Viper Fibre Placement Systems claim to improve the productivity and precision of composite construction. They are said to combine the advantages of filament winding, contour tape laying, in-process lamination and computer control to automate the production of complex parts that conventionally require extensive layouts.

According to Cincinnati the Viper FPS-1200 at Bell Helicopter automatically places 12 tows of composite material each up to 3.2mm wide. The 12 tows provide a maximum lay-up bandwidth of 38mm per pass. Each tow can be independently dispensed, clamped, cut and restarted for uniform lay-up over curved, convex, concave and compounded contoured surfaces without wrinkles or bunching. Start/stop tow controls allow the creation of precision openings and edges, minimising the need for subsequent trimming and hand finishing.

By using seven-axis dexterity, the Viper FPS-1200 manipulates the 12 fibre tows in programmed three-dimensional lay-up of contoured shapes and complex geometrics at optimum angles, layer-on-layer, for maximising part strength and stiffness, while minimising, part weight.

Designed for computer-controlled fibre placement of smaller, highly contoured composite parts, the Viper FPS-1200 provides minimum Z-axis travel of 4.6m, X-axis travel of 1.5m, and maximum part diameters of approximately 1.8m. The machine can reportedly place fibre tows at speeds of up to 45m per minute with an accuracy of 1.25mm.

Advanced Cincinnati controls and software, designed specifically for composite processing, are said to make it easy to programme and control Viper multi-axis movements for lay-up of complex geometrics. Proprietary Acraplace programming software translates CAD tooling and part data into seven-axis commands, developing the paths and tool rotations for applying the composite materials to curved and geometric surfaces while keeping the compaction roller normal to the surface. A simulator module confirms the part program with 3D animation, while integrated collision avoidance post-processing of the NC program automatically detects and corrects for interference.

Ron Hennies, composites product manager at Cincinnati Machine, says:

The Viper FPS-1200 will fabricate composite blade spars for the tiltrotors on the revolutionary vertical take-off and land business and utility aircraft, as well as other composite structures.

The Bell 609 combines the hover characteristics of a helicopter with the range and speed of fixed-wing transports. Using technology developed by Bell on the V-22 Osprey joint service transport, the rotors tilt from vertical orientation on take-off to horizontal for level flight.

Designed to carry six to nine passengers, the Bell 609 eliminates the need for runways, while providing cost-effective, point-to-point transport at cruise speeds of up to 275 knots and ranges up to 1,207km. Bell officials see the flexible design being used for executive transport, natural resource exploration, emergency medical evacuation, disaster relief and Government support roles.

Details available from: Cincinnati Machine UK Limited. Tel: +44 (0)121 313 5334; Fax: +44 (0)121 313 5379; e-mail: david_wiggins@cinmach.co.uk