Cutting Tool Engineering
July 2011 / Volume 63 / Issue 7

Taking Grinding to the 'Next Level'

By CTE Staff

Damen-1.tif
Courtesy of United Grinding

The Studer S40 CNC cylindrical grinder from United Grinding enables Damen Carbide to process shafts up to 63" long and weighing 286 lbs.

Technology change has a universal impact on parts manufacturers—from the largest plant to the smallest shop. Most of the manufacturers who have taken the leap and invested in new technology have found they’ve made the right decision because of the productivity gains they’ve realized. What some might not have foreseen, however, is that once they’ve made the leap forward, they have to continue that process if they expect to keep up with changing technology.

Damen Carbide Tool Co. Inc. is one manufacturer that understands it has to keep leaping. “You have to keep up with the technology or the doors will be closed,” said John Bachmeier, company president. He added that the company has always done that.

The Wood Dale, Ill., job shop dates to 1948 and produces wear parts, dies, saws, knives, slitters, special tools and other components made of tool and alloy steels, carbide, ceramics, titanium and exotics via milling, turning, EDMing, and jig, flat, ID, OD and profile grinding. “You name the industry, and somewhere on a vendor list you’ll find Damen Carbide,” Bachmeier said.

He noted that the shop has long been able to hold tolerances of ±0.0001" and tighter and impart surface finishes as fine as 2µm to 3µm rms.

Nonetheless, the shop needed to replace its reliable battery of grinders and take its grinding capabilities to the “next level” to reduce cycle times and expand the types of parts it could produce while maintaining a high level of precision.

Bachmeier called Integrated Machinery Systems, an Itasca, Ill., distributor of machine tools and automation products that Damen Carbide had worked with in the past. Together, they looked at several grinding machine builders and compared features, programming, part loading/ unloading, processing capability and wheel and dressing monitors. Based on their research, they were drawn to the various grinder brands from United Grinding Technologies Inc., Miamisburg, Ohio.

Over time, Damen Carbide purchased five CNC Studers: three S40 cylindrical grinders, an S31 cylindrical grinder and an S22 production grinding platform. In addition, the shop bought a Blohm Profimat MT 408 for surface, profile and creep-feed grinding and a Walter tool and cutter grinder, with another Walter on order.

The new equipment enabled Damen Carbide to reduce cycle times, particularly ID and OD grinding on the Studer machines, and allowed one person to operate multiple machines.

In addition, the shop was able to bid on RFQs that it previously was unable to because of capacity limitations. For example, the S40, which provides up to four grinding wheels via a turret wheelhead that automatically swivels and has a high-resolution B-axis and C-axis for form and thread grinding, gives Damen Carbide the capability to grind longer and heavier workpieces—up to 63" and 286 lbs. Previously, the maximum length was about 25".

“The CNC S40s have opened new doors to customers in the long-shaft business,” Bachmeier said, noting that it’s possible to grind a small part in a big machine but not vice versa. “We make parts only 1" long in those machines.”

Also, the S22’s HSG (high-speed grinding) package, which offers circumferential speeds up to 140 m/sec., enables out-of-round grinding of any shape, such as hexagon, triangle or square. “It calculates so fast that I can put a round part in the machine and make a square out of it,” Bachmeier said.

Damen Carbide still uses some of the older grinders, even circa-1950 ones, to perform secondary operations and produce small part runs because it’s difficult to make a profit setting up those jobs on a CNC grinder, Bachmeier explained. “Once you have 10 or more pieces, then it’s worth using the CNC.”

Besides grinding speed, a major difference between older and new technology is the price of the machine. “Back in the day, you could buy a machine for $30,000, $40,000, $50,000,” Bachmeier said. “That’s not even a 10 percent down payment on one of these machines.”

While the financial risk for Damen Carbide has increased, so has the reward. “When we put on our Web site that we had five CNC Studers, it was amazing the number of new and large customers that called us,” Bachmeier said.

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