NC Product Shootout Yields Rewards For Automotive Mold Supplier

Tycos Tool and Die (Toronto, Ontario, Canada) supplies automotive fascia molds to several major automotive manufacturers, including the Big Three: DaimlerChrysler, Ford Motor Co. and General Motors. A fascia mold contains complex geometry, where details and precision are key. Additionally, machining one 22,000-pound mold can take up to ten days of detailed work, and a small error can scrap a $500,000 mold. Tycos used various NC programming solutions at each of its 10 different machining centers, with most programming taking place on the shop floor.

When Tycos purchased new CNC machines in 1997, the managers and machinists became reasonably certain that an update to the existing five-year-old NC system would produce a significant return on investment. "With the improvements in high speed machining technology that today's CAM packages provide, we identified this area as one that could really pay off in terms of improving productivity," says Pat McCarthy, a machining coordinator.

Mr. McCarthy, his manager Keith Johnston, and general manager Pat Radice, were determined to find an integrated, fast system to update the company's old stand-alone software. They selected three NC solutions to compare side by side. During a three-month evaluation process, Mr. McCarthy and his colleagues applied 20 different grading factors that covered service, quality and performance. Once the parameters were set, Tycos tested the 3D functionality of each package by cutting three identical complex mold components.

The result was that hyperMILL, by OPEN MIND Software Technologies, Inc. (Southfield, Michigan), emerged as the winner, scoring about 50 percent higher than the second place vendor. Reasons for its score include the following.

• Cutter Path Generation—A sample test showed that hyperMILL generated a roughing path with a 4-inch diameter face mill in 1.5 hours, and a roughing path with an 8-inch diameter face mill in 3 hours. This resulted in significant savings in these machining routines.
• Surface Appearance—HyperMILL topped the ratings by producing a finish rated "excellent" by using true scallop machining, which calculates the step-over distance normal to the surface rather than normal to the tool vector. This keeps cuts equidistant from each other regardless of surface curvature and results in a much more consistent chip load on the cutter. Pencil milling and rest milling features automatically identified all areas that were not cut based on one tool size, then automatically cut the areas with a smaller tool so that there was uniform stock left at surface intersections. Relieving the larger volume of material allows for less tool deflection and noise when cutting corners.
• User Friendliness—HyperMILL led the group in ease of use, providing logical icons to run the software. Operators were able to use hyperMILL after two days.
• Engineering Computing Time—Performance tests showed that hyperMILL had the fastest machine cutting times and cutter path calculations.

After hyperMILL was selected, Tycos implemented the system at several stations.

Using hyperMILL, machinists and production managers at Tycos have reduced cutting time by more than 30 percent, while significantly increasing productivity. Additionally, the leadtime from CAD file to machine has been reduced from 18-24 hours to as little as 10-15 minutes. "With our old package, we were required to initially prepare the files, which would take hours," explains Mr. McCarthy. "HyperMILL uses a surface mesh file, which significantly reduces our cycle time, creating faster and more efficient cutter paths. With hyperMILL, it is now possible to machine to closer tolerances, allowing more material to be removed at the roughing stage, which benefits us in downstream operations. Because more material is removed during the roughing operation, finishing tools and machines will undergo less wear and tear." During the introductory use of the system on one machine, operators saw a 15 percent reduction of roughing time per large component, while downstream machining was also reduced by 15 percent per component. Since cutter path generation is now a concurrent operation, the need for a non-integrated system to create cutter paths has been eliminated.

OPEN MlND's responsiveness to Tycos was another strong factor, especially because the product tests could not interrupt workflow. "After evaluating Tycos' needs, we implemented changes to the hyperMILL product that not only satisfied the customer's specific requirements, but also made hyperMILL a more robust product," says Terry Senish, technical sales manager at OPEN MIND.