SOARING WINGS WITH HIGH FEED MILLING

In March 1990, the Supreme Council of Lithuania announced its independence from the Soviet Union, restoring the independent Republic of Lithuania. Since then, the capital, Vilnius, has rapidly transformed and is emerging as a modern European city. Many of Vilnius? older buildings have been renovated and a commercial zone is being developed in the new city center. The location is home to JSC GKF Sparnai, a company that specializes in high accuracy machining for the laser manufacturing, medical, aviation and telecommunication fields.

The name "Sparnai" literally means "wings," and this manufacturer has soared to prosperity, to the point that it now has many global companies on its client list. The company has grown steadily since it was founded in 1988 and today exports to some 40 customers in over 21 countries.

Sparnai machines aluminum, titanium and stainless steel, as well as plastic. A couple of years ago, the company managed to machine 23 tons of aluminum on a monthly basis for the aerospace and telecommunications industries. The hallmark of the company is precise and accurate machining, as Gintaras Kasuba, the company?s Managing Director explains, "Quality is the most important thing ? when you get onboard an airplane, for example, you want to be sure you will reach your destination. If you fly on an Airbus 380, you could find components that were made here in our workshop."

Competitiveness has also driven the company to excel. "Just before we started to use new, high productivity tooling, we produced some parts for a company in Israel that took just over 40 minutes each to machine," says Mr. Kasuba. "The customer told us that a competitor could produce them in just 31 minutes. Of course, we felt insulted and set about looking for ways to optimize the process. The answer was a high feed milling cutter, the R217.21, from Seco Tools. In the end, we got the machining time down to just 17 minutes per piece."

High feed milling is a roughing method developed for high metal removal rates to increase productivity and save machining time. High feed milling uses a small depth of cut ? usually no more than 2 mm ? to produce a thinner chip that carries the heat away from the cutting edge. This approach reduces heat generation to extend tool life and provides a higher metal removal rate than normal; over 1,000 cm per minute, or up to 200 to 300 percent faster than traditional milling. The reason for this is that high feed milling takes advantage of small setting angles (45 deg or less). Due to the geometry of this cutter, it absorbs the forces axially, i.e. up towards the spindle, thus reducing the risk of vibrations and maximizing process stability. This, in turn, allows for the higher cutting parameters.

As customers become more demanding and request more complex machining tasks, Mr. Kasuba has introduced this high feed milling cutter to new applications. For example, the company has been milling at 11 meters per minute on stainless steel with this cutter. Regularly used on three or four of the company?s machines, the cutter helps to produce approximately 5,000 more machined parts per year than three years ago. Components currently being machined using this cutter include parts that are destined for railway and subway systems.

Another success was a part produced for an American company. Two 35 mm holes per workpiece were drilled in approximately six minutes before new tools were introduced. Seco suggested a Perfomax indexable insert drill for the task of drilling the holes in stainless steel and titanium. This low-friction coated drill body offers high stability, and its strong inserts deliver excellent productivity. The tool is capable of very high feeds and speeds. Subsequently, the holes were machined in just eight seconds.

Future plans include purchasing a 9-axis machine and continuing efforts to find people with the right skills and experience to operate the machines. To help address the need for skilled operators, a program has been set up with local schools whereby students are trained while they study and then, if standards are met, they are employed by Sparnai. This initiative is already paying off. Last year, two operators were hired from a training institution and are now being trained in-house to operate the more complex machines.

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JSC GKF Sparnai, Þirniø st. 28A, LT-02120 Vilnius, Lithuania, +370 5 261 9909, Fax: +370 5 262 7891, www.sparnaigkf.eu.

Seco Tools Inc., 2805 Bellingham Drive, Troy, MI 48083-2046, 586-528-5200, Fax: 586-528-5250, www.secotools.com.