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moldmakingtechnology.com 13 in Georgia, three in Mexico and one in China—that churn out plastic parts for the medical, packaging, consumer prod- ucts, construction and agricultural industries, among others. Presses sitting just down the hall from the toolroom at the 70,000-square-foot headquarters facility offer capacities rang- ing to 2,000 tons. Among the company's largest presses are two 3,500-ton behemoths at its 100,000-square-foot opera- tion in Oshkosh, Wisconsin. This equipment employs tools that exceed the DeForest shop's size limits, even with the new Kitamuras. Nonetheless, the greater the variety of tooling that can be produced in-house, the better, Kollath says. After all, mold design and building is one of the company's five "keys to success" for ensuring optimal, cost-effective performance of plastic parts. Those tasks fall largely to Kollath and his team, who support the four Wisconsin facilities with new molds as well as repair and maintenance services on all tools, regardless of the manufacturer. Given that the operation's importance to the overall company exceeds its relative size, EVCO Plastics President Dale Evans was quick to act on long-standing plans to expand the toolroom's capacity once the timing was right. With a maximum table load of 13,200 pounds, the Bridgecenter 10 provides additional capacity and power for heavy roughing of larger molds. Power and Finesse Combined Kollath points out that EVCO's molding business isn't limited to large parts. New builds and maintenance and repair opera- tions alike commonly involve tooling designed for presses as small as 28 tons. Nonetheless, he says there has been a marked trend in recent years toward jobs that exceed the size capacity of what was once the shop's largest machine, a C-frame vertical with X-, Y- and Z-axis travels of 50 × 24 × 30 inches. In contrast, the Bridgecenter-8F offers X-, Y- and Z-axis travels of 80 × 42.7 × 28 inches across a 35.4 × 98.4-inch table with a maximum weight capacity of 6,600 pounds. This larger work envelope enabled the shop to take on molds designed for the company's 1,500-ton presses, a significant increase from the previous limit of 1,000 tons. Meanwhile, the machine's multi-step, gear-driven spindle can be adjusted as needed for higher torque or higher speed to a maximum of 20,000 rpm. By comparison, the previous machine had to run at painfully slow feed rates to avoid breaking smaller tools once it moved from roughing to more intricate work, Anderson says. In many cases, unwieldy parts had to be moved to a sinker EDM instead. Beyond Size and Speed Kollath emphasizes that capacity and spindle speed weren't the only limitations of that aging vertical. Upon installation in December 2011, the Bridgecenter-8F broke many of the result- ing bottlenecks. For example, operators often had to let the older machine cool after roughing, then warm it back up again to find the "sweet spot" for finer details, Anderson recalls. Even then, they had to regularly compensate for thermal growth. In contrast, the Kitamura is thermally compensated through the builder's Intelligent Advanced Control System (IAC), which uses regulating sensors and a machine-efficiency monitor to provide data on variable compensation values to the machine offsets. According to the builder, the system keeps displace- ment to less than 5 microns (0.0002 inch). The spindle is also chilled. As a result, operators can press "cycle start" and walk away. "They have a lot more confidence in what comes off the machine," Anderson says. The machine's raw precision also limits the need for opera- tor intervention. "We can machine highly contoured shutoff surfaces to net zero and know that they'll mate up perfectly," Anderson says. In some cases, the shop machines to a surface tolerance of -0.0005 to aid in venting and shutoff. As a result, operators spend far less time polishing, hand-fitting and spotting. Features contributing to this precision include the double-column, bridge-type design with slanted cross rail, rigid, solid boxway construction, and linear scale feedback in all three axes. The machine also unlocked new, cost-saving options for the design staff. Given previous limitations for larger work, they were often forced to insert certain core and cavity