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Jim Mokoski, a manufacturing engineer with Pratt & Whitney Aircraft in Middletown, Conn., was looking to replace an aging CNC on a seven-axis Butler Newall grinder. The grinder, one of two in his department, is used to finish-grind blade tips on jet engine turbine rotors. This grinding process is the last step before a rotor, worth thousands of dollars, is installed in an engine. The other grinder had a GE Fanuc 150-MA control with some limited automation software. Mokoski wanted the older machine upgraded, having at least the capabilities of his newer machine.
Both grinders already had laser-measuring devices that accurately measured each blade tip under rotational load. With this laser data, machine operators used a complex set of rules to analyze the blade measurements, determining the grinding depth of each stage and whether or not to replace blades that were out of range. Once grinding started, operators manually controlled the grinding while observing the laser measurements to make sure the end results stayed...