Electrical Discharge Device Dresses Metal-Bonded Grinding Wheels

Available from United Grinding, the Studer WireDress electrical discharge wheel dresser uses the wire erosion principle to dress metal-bonded grinding wheels on the grinding machine without the need to remove the wheel for external dressing. The electrode wire is drawn with a small gap tangentially past the machining point at a constant speed of 100 mm/sec. The opposite pole is the grinding wheel, which moves at peripheral speeds of 50 to 140 m/sec. during dressing, with the grinding oil functioning as the dielectric medium. Feeds of 15 to 25 mm/min. can be achieved when dressing a typical metal bond, the company says.

This process generates largely free geometries and intricate contours with internal radii of 0.2 mm and external radii of 0.05 mm on the grinding wheel, achieving removal rates as high as 80 mm³/min. The grain is said to retain its original shape during this contactless dressing process. Thanks to the high proportion of grain space, the wheel is very free cutting, enabling more grinding oil to enter the grinding slot for high feed and less workpiece deflection. The dressing intervals can be longer, but complex contours can also be dressed at shorter intervals, according to the company.

The wire reel in the dressing unit contains enough wire to enable continuous dressing for approximately 16 hr. without interruption. The used wire is cut into short pieces immediately after the dressing process and collected in a container. The ceramic disc which guides the electrode wire is very resistant and only wears after several hundred hours, the company says. The WireDress control unit is integrated into the grinding machine’s control system and has all necessary dressing functionalities as well as the StuderDress program for intelligent profiling with path optimization.