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New CAM Program Cuts Machining Times

June 21, 2010
At a fast-expanding, high-volume automotive forging operation, a simple switch to Delcams PowerMILL reduces machining times for finished closed-die forging by 40%.

Kobe Aluminum Automotive Products LLC (KAAP) has been able to reduce machining times and reduce hand finishing on automotive parts thanks to its switch to Delcam’s PowerMILL CAM system. The change produced savings both during programming and on the machine; the software that the company had been using was difficult to learn and produced programs that took too long to run.

KAAP is a partnership of Kobe Steel (60%) and two trading houses, Mitsui & Co. Ltd. (25%), and Toyota Tsusho Corp. (15%), that produces forged aluminum suspension components. It started up in 2005 with a single mechanical press, but added a second and a third in 2006, and a fourth in 2008.

The partners initially invested $80 million in the Bowling Green, KY project, to produce 280,000 forged aluminum components per month, principally for Nissan North America, General Motors, and Honda Manufacturing of America. Automotive manufacturers’ use of aluminum forgings for suspension systems is increasing, as part of the design changes intended to reduce overall vehicle weight and increase fuel economy. KAAP was developed to help meet this demand, and the partners recently outlined plans to establish a comparable operation in China’s Jiangsu Province, starting up in August 2012.

Delcam is a developer of CAD/CAM solutions, including design, manufacturing, and inspection software for producing complex-shaped products.

Some users of PowerMILL attribute the increased accuracy and surface finish quality to its improved visual feedback. “It is much faster when handling large files of complex data,” one user said. “We can generate a better finish and so produce a higher quality part for the customer.”

PowerMILL is Delcam’s specialized NC CAM software for complex shapes, not only for automotive components as at KAAP but parts for aerospace components, medical devices, and toolmaking. Among the software’s critical features are its wide range of strategies, including high-efficiency roughing, high-speed finishing, and five-axis machining techniques. It also achieves exceptionally fast calculation times and offers powerful editing tools, for highly effective machine tool operation.

At Bowling Green, KY, KAAP tool shop manager Victor Steele explains that switching to PowerMill helped to reduce machining cycle times by 40%, “primarily because the rest-machining capabilities in its offset area-clearance strategies greatly reduce air-cutting time.

“Its optimized and interleaved constant-Z finishing strategy has improved surface finish to the point that manual finishing has been reduced by 50%,” Steel adds. “PowerMILL is also easier to learn, with the result that new programmers can be trained in less than an hour.”

The biggest CNC programming challenges for the Kobe operation are closed forging dies. KAAP normally roughs out the parts on its Mazak FJV-3580 vertical machining center and performs finishing operations on a Mazak Nexus vertical machining center.

“We were able to program these parts with the CNC software that we used in the past, even though it was not very intuitive,” said Steele. “Roughing operations were relatively slow because the tools spent much of their time cutting air.” The problem with KAAP’s previous software was that each successive cutter traced the complete path of the part profile, even where was nothing for it to cut, either because the section had already been finished or because the cutter was too large.

Kobe Steel’s Japanese operations had successfully programmed this type of part with PowerMILL, and recommended that KAAP try the Delcam software. “One of Kobe Steel’s programmers from Japan visited us and showed us how to use PowerMILL,” said David Taylor, a KAAP plant engineer. “Despite his limited English, he was able to teach us to use the program without a great deal of difficulty. We liked the way the user interface is laid out.”

Later, KAAP programmers had two days of on-site instruction from one of Delcam’s PowerMILL trainers. “As we got to know the software better, we were impressed with the large number of powerful machining strategies that it offered to help optimize cycle time and the accuracy of our machining operations,” he added.

Taylor said that PowerMILL’s simulation capabilities are another improvement over the software previously used there. The projections achieved via simulation give operators extra confidence in their machining efforts by predicting axis reversals and surface quality. The simulation often identifies opportunities for improvement in the machining process, so the programmer can easily change or reorder operations to prevent crashes or reduce cycle time in the actual machining operations