Centerless Grinder is a unique form of machining procedure which utilizes abrasive rather than rotary cutter. The main advantage of using an abrasive wheel against a work surface is that the tool is placed above the work surface and the abrasives are directed along the work axis. The work piece is not touched at all during this process. This type of grinding generally produces faster turning pieces than other types of grinding. The use of this unique technology opens up many new opportunities in the machining operation.
There are two types of CNC centers: fixed and mobile. In a fixed CNC center, the machine works in an absolutely fixed manner, just as it did when it was first invented; however, the workrest or work platform is movable. With a mobile center, the machine is mobile and the distance between the workpiece and the grinding wheel can be changed as needed. Each of these wheels has a pair of rotating wheels; the one on the top of the CNC machine is called the working wheel.
In a traditional CNC center, the workpiece is placed on workers with a fixed distance between the center of the workpiece and the worker’s surface. The distance between these two points determines the roundness of the workpiece; the more circular the workpiece, the larger the circle of the workers must be. When the distance between the workers and the workpiece is changed, the working wheel moves closer or further from the stationary workpiece until the desired roundness of the workpiece is achieved. The two types of centers are stationary or fixed, and movable or moveable. A movable or moveable center can be precisely positioned relative to the workpiece; however, the work must always be turned or rotated so that the turning motion can reach the workpiece and the workrest in a position that is perpendicular to the stationary work.
The most common type of centerless grinder machine setup is made up of a variety of wheels that are secured to a base. This base is typically constructed from metal. There are many different designs available for this type of machine setup. The wheels may be secured to a steel frame, a wood base, or to a sturdy plastic material.
A second type of common centerless grinder unit setup involves the use of a cutting wheel. With this type of machine setup, two or more cutting wheels are secured to a base. The cutting wheel moves in a horizontal plane along the base and the edges of the wheels are not touched by the abrasive material. This design allows for even wear of the wheels by even smaller particles of material. In addition, the wheels are not restricted by the roundness requirements of the work piece.
Most commonly used models in the market are made up of aluminum and steel materials. The aluminum centerless grinder units are usually designed with a straight edge. With the key type machine, there is an adjustable angle control that allows the wheels to be turned in a clockwise and anti-clockwise direction. Typically, this type has larger holes than the through-feed grinding wheels. This type of unit also uses a clutch system for the transmission of the grinding forces.