Original Date: 05/08/1995
Revision Date: 01/18/2007

Implementation of the McDonnell Douglas Aerospace (MDA)-St. Louis’ large, flexible Trim System that combines an Abrasive Water Jet System and High Speed Spindle Technology will be completed by July 1995. This DNC system will increase trim edge quality, reduce manpower, and reduce perishable tool usage while providing a capability for large composite and complex contour parts. All trimmed parts will only require one set-up.

The Advanced Trim and Drill Cell is a 13-axis, fixed-bed, gantry-type machine capable of trimming with either abrasive water or with a traditional high-speed spindle. This machine is designed to trim flat and compound curvature composite structures. The work envelope is 12 feet (y) by 40 feet (x) by (2) 42-inch z’s, where each z axis uses individual rotary axes. An automatic carousel-type tool changer allows the router section a smooth transition to and from required cutters. The Abrasive Water Jet Process uses high pressure water, up to 60,000 psi, and garnet abrasive to form a slurry capable of trimming composite and titanium structures.

Additional capabilities included in this system are drilling, countersinking, reaming, seal groove cutting, chamfering, and core carving. The system utilizes three closed circuit color cameras to observe the process, a waste removal system that removes solid particles from the water jet waste effluent, a 10-station carousel tool changer for automatic tool exchange, probing capabilities for accumulation of SPC data, and a redundant water pump capable of being switched on the fly, limiting system downtime.

Part location is accomplished through the use of vacuum cups and surface hole patterns located directly in the holding fixtures. A dry vacuum system is installed to reduce airborne composite dust.

Early process verification data has shown significant cycle time reduction in both set-up and actual trim, with set-ups being reduced from eight to one over hand trim methods. Increased quality is expected through the utilization of programmable feeds and speeds along with reduced trim tool damage normally encountered in hand routing. With a total investment of $2,425,517, including equipment and facility costs, the five-year annual savings is projected to be $990,872.

For more information see the Point of Contact for this survey.