Tube finishing machine handles straights, curves

Situation

Ferrita Sweden AB, Köping, Sweden, specializes in stainless steel exhaust systems, mainly for passenger cars. The company has an international reach, making systems for brands from all over the world. It also makes systems for niche models—the Chrysler Viper, Maserati GranTurismo, Ferrari 360 Spider, Lamborghini Murciélago LP640, AC Cobra, and so on. It also takes custom orders for automobiles and makes systems for commercial vehicles and boats.

The company has several goals. First, it strives to make exhaust systems that last longer than the cars. Second, it has to make systems in an endless variety of configurations. Third, appearance is critical. On some cars, such as the top fuel dragster raced by Micke Kågered Racing, the exhaust system is always on display, so it has to look good.

Because of the last goal, a good surface finish is critical, and the finish has to be consistent along the length of the entire system.

Resolution

Getting a high-quality, consistent finish on straight sections and on the inside and outside of bends is a challenge. To accomplish this, the company purchased an ML150 tube finishing machine, manufactured by NS Máquinas Industriais. The machine is open at the sides; between the two openings, two sanding belts face each other. Each sanding belt runs around a system of three rollers mounted on opposite sides of a wheel. While the belts run over the rollers, the wheel rotates the entire belt assembly. This action ensures that abrasive material contacts all points around the tube’s circumference.

Each belt has a tension roller for tensioning the belt; a tuner roller for adjusting the belt for the workpiece diameter; and a drive roller connected to a variable-speed motor that allows the belts to spin independently of the main wheel. The operator adjusts these belts to accommodate specific tube diameters.

As the operator feeds the workpiece through the machine, the two belts work over the tube’s surface, sweeping over it as the wheel rotates the belts. Because the machine profile is narrow, it can handle most geometries, and the operators rarely have to contend with machine interference.

AM Machinery Sales Inc., 114 Camars Drive, Warminster, PA 18974, 215-293-0333, www.ammachinerysales.com