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A Grinder That's More Like A Milling Machine

July 10, 2007
Bridgeport's FGC 2 makes easy work of blades and vanes. The introduction of Bridgeport's FGC 2 flexible grinding center gives shops that machine aerospace blades and vanes an alternative to big, expensive grinding machines. The FGC 2 ...

Bridgeport's FGC 2 makes easy work of blades and vanes.

The introduction of Bridgeport's FGC 2 flexible grinding center gives shops that machine aerospace blades and vanes an alternative to big, expensive grinding machines.

The FGC 2 flexible grinding machine performs what Bridgeport calls creepfeed "milling" that uses conventional aluminum oxide grinding wheels as its "cutters." Bridgeport, which is part of the Hardinge Group (www.hardinge.com), said its new machine cuts blades and vanes faster and more efficiently than ever before.

Unlike other builders that use grinding machine platforms, Bridgeport constructs the FGC 2 five-axis profile grinder on a vertical machining center platform that provides flexibility for handling different part families and for quick changeovers through changes in software and setups, rather than changes in hard tooling and setups. The company said this gives shops the potential to reduce setup times by 90 percent, to cut total machining times by as much as 50 percent and to cut leadtimes by as much as 60 percent.

Bridgeport has been manufacturing a version of the FGC machines in the United Kingdom for the past eight years. Rolls-Royce purchased some of the first FGC 1s, but those models are different from the new version.

The FGC 1s were smaller than the FGC 2, and were built as Cframe-style machines. They had single-roll dressing units, operated in up to four axes and used one coolant nozzle.

FGC 2s are traveling-column-type machines that weigh 30,100 lb and have 4-axis and 5-axis simultaneous movement, double dressing rolls and dual coolant nozzles.

Double-roll dressing units on the FGC 2s feature quick-change arbors for loading diamond dressing rolls while the machine is running, and dual CNC programmable coolant nozzles clean and cool grinding wheels to extend their working lives and reduce cutting forces. In addition, the machine's filtration system filters coolant down to 10 microns.

FGC 2s sport 2-axis rotary indexers and 8,000-rpm vertical spindles. Automatic tool-changers accommodate 12 grinding wheels with diameters to 10-in. and milling tools to 2.9 in. in diameter and to 11.8-in. long. Tool-to-tool change time is 3.5 sec

"With this machine, we will expand our commitment to the aerospace industry," said Patrick Ervin, president of Hardinge. The company plans to take the FGC beyond where it is today capability wise, and while the machine excels in blade and vane processing, Ervin foresees success for it in medical and other applications.