CH-53 Gun Yoke

Augustine Die Mold, Inc., of Somerset, Pennsylvania, is producing gun turret components for various military helicopters, including the Sikorsky CH-53. Machining a 12-inch wide, 18-inch long, 10-inch thick, horseshoe-shaped aluminum gun yoke was a challenge roughing operations alone were taking over 3-4 hours for each yoke. In addition, existing processes created stresses that distorted the part, requiring straightening operations that consumed about an hour. Augustine sought the help of the National Center for Defense Manufacturing and Machining NCDMM to reduce machining time and eliminate residual stress. NCDMM analyzed the operation and applied modal analysis technologies from alliance partners Design Manufacturing Solutions, Inc. DMS and Manufacturing Laboratories, Inc. MLI. Modal analysis can determine the cutting characteristics of individual tools while they are mounted in the machine tool. The information is used to create stability lobe diagrams revealing the combinations of cutting speeds and feed rates that can best deliver high productivity without chatter. NCDMMs testing resulted in an immediate 85 percent reduction in time required for roughing, elimination of time required for straightening operations, and reductions in finishing operations.