CTMA Project #: 150337, 150339
Problem: Aircraft structural components for wings, stabilizers, tails, and floor supports must be strong yet lightweight. Traditional manufacturing means involved fabricating structures using both machined and sheet metal parts fastened together with rivets and screws. Fabrication was labor intensive and all the fasteners added unnecessary weight. The improvement preferred by air frame builders is to replace the fabricated structures with equivalents machined from monolithic blocks of lightweight metals such as aluminum and titanium. The resulting reductions in weight and labor costs made the monolithic machining process a clear winner.
However, room for further improvement remained. The realities of aircraft geometry mean that non-orthogonal angles, necessary for forming pocket walls and so forth, and the most efficient machine tools, (five axis milling machines), were difficult to program. Furthermore, the great amounts of material to be removed demanded very efficient, high speed machining processes. The HITHRU project attacked both needs by addressing choke points in manufacturing processes for monolithically machined components from process planning to the machining processes.
Benefit: The project demonstrated reductions in NC programming and machining times. The deployment project phase achieved significant savings on actual F-15 parts made by Warner Robins Air Logistics Center (WR-ALC). Programming time was not tracked by part number however, so direct comparison of non-recurring costs was not possible. Cycle time reductions for the first part was reduced by 9.5 hours per part, saving about $200,000 over a 200 piece run. Cycle time for both the 2nd and 3rd parts was reduced by six (6) hours each.
Solution/Approach: HITHRU addressed these issues directly, using a knowledge-based computer-aided process planning (CAPP) tool with computer automation to both speed manufacturing process planning and to reduce knowledge demands on the user. Furthermore the tool made use of five-axis machine tools, thereby reducing the number of setups required for machining and also produced NC programs optimized for high-productivity machining. HITHRU and software now known as Cimskil™, a product HITHRU helped develop did not address the issue of creating 3D solid models but did address productivity improvement in manufacturing process planning and higher productivity machining processes for aerospace aluminum and titanium parts.
Impact on Warfighter: If implemented readiness and availability could be favorably impacted by improved cycle times, greater throughput, increased reliability, and reduced costs.
DoD Participation:
- U.S. Air Force (WR-ALC)
Industry Participation:
- Cincinnati Lamb, a Division of UNOVA Industrial Automation Systems, Inc. (formerly Cincinnati Machine)
- Technology Answers Corporation
- NCMS
