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Advanced Machining & Gear, Inc., (AMG), a growing 35-employee shop in Grove City, OH, runs 11 shifts a week over five and a half days. And to reduce costs, the company focuses most of its energy on reducing cycle times. Says AMG's Kyle Dunaway, "Cycle time is the centerpiece of competitiveness. When we drive it down, we also deliver faster and handle more work without new capital investment. And while quoting more competitively, we protect our margins, especially in longer-run repeat work."

Since starting the retooling in 2003, AMG has tripled the number of CNC machines, from five to 15, and picked up much more long-run business, leading to a more stable revenue stream. In July 2006, in fact, they moved to larger quarters to accommodate their growth.

AMG's first candidate for retooling was a wedge, which the company milled on all six sides. The wedge is made of mild 1018 steel machined from lengths of bar stock. The initial order was for 1,200 parts with the likelihood of repeat orders. The wedges measure 5 inches long by 4 inches wide by 2 inches thick, with a 15-degree slope on both sides. There are two 3/4 #10 tapped holes. AMG was starting to run them in an eight-up setup on a four-axis Matsuura horizontal CNC mill, using a 2-inch zero rake milling cutter and a solid cobalt twist drill for the holemaking. Cycle time to mill and drill each batch was 182 minutes. Milling feed and speed for roughing was 40 ipm at 700 rpm.

The company retooled with an Ingersoll 1-inch IC Form-Master button cutter and drilling with Qwik-Twist drills. The drill features a replaceable carbide tip that fits onto an alloy steel shank with 0.0005-inch repeatability to datum, according to the company. Net effect was to cut total cycle time more than 50 percent, to less than 79 minutes. That saved over $10 per part and about $15,000 for the job.

Next, the company tackled a small piston and mating cylinder made of cast iron. With intensive grooving and radii typical of such small compressor parts, the job required a combination of milling and turning operations. As the result of retooling, the piston that took 22 minutes per part is now done in 14 and a half, and the cylinder head that took 26 minutes now takes just 18. Machining saving per part: around $10.

The company also mills with the Quad Drill featuring DNMG turning inserts. These drills feature a thick square insert, positive rake presentation and positive chip breaker, the company says.

For rough milling of steel or cast iron, which accounts for the majority of chipmaking time in AMG's operation, the company has pretty much standardized on 100 ipm at 1,500 sfpm. "The standard for roughing is to take a 0.022 inch chip load at 1,000 sfpm, up from 0.010 inches before," says Dunaway.

Most of AMG's heavy hogging of flats is done with Ingersoll V-Max tangential milling cutters. The inserts lie flat around the pitch circle, which aligns their strongest cross section with the main cutting force vector, thus permitting higher cutting forces and higher removal rates.

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Editor's Note: Artwork courtesy of Ingersoll Cutting Tools, www.ingersollcuttingtools.com.