Centerless grinders are a type of rotating grinder used in CNC mills. This type of grinding process eliminates the need for a spindle drive or other power source to move the grinding wheel across the work surface. This enables a grinding wheel to be used in applications where space is an issue, but at a higher cost of energy and complexity. Because of the centerless design, these machines can also be used in applications without a spinning motion, as well.
When comparing centerless grinding machines to similar products found in other types of machines, there are a few key differences. The first is the lack of a spindle drive. Typically, a CNC milling machine will include a spindle containing gears and rollers that allow it to spin at a high rate of speed. With the absence of a spindle, the product must be ground at a slower, more consistent pace using a manually controlled machine.
The second difference is the lack of a holding area for the workpiece while the grinding wheels are in operation. Typically, a holding area will be designed to keep the workpiece from being damaged during the process. In a CNC mill, however, the workholding area is generally small. As a result, the grinding wheels may damage the workpiece before the desired end result has been achieved. While some brands include a buffer zone, others do not. This can limit the applications in which the centerless grinder can be used.
The third difference between this type of machine setup and traditional machining is associated with part quality. Typically, a CNC mill will use a variety of titanium wheels to create the desired result. In this case, the centerless grinder will be more expensive than those machines in which the wheels are made from other materials. However, the result will be significantly better than that from a CNC machine. In addition, CNC machines generally utilize a smaller crank that requires less material to complete the same result as a larger one.
The final difference refers to the way the material is held during the grinding operation. Typically, centerless grinders hold two or more workholding components while the material spins around the stationary components. In this case, the workholding system may be a small belt conveyor. In some cases, however, it will be a separate part of the CNC machine. This is especially true for precision parts where a single, large workholder is preferable.
All types of CNC machines grind, but there are differences in the way they do so. A centerless grinder is used to create a more durable product by avoiding some of the more common problems associated with standard CNC machinery. Specifically, through-feed grinding and flat bed grinding are two of the most common types of CNC milling operations. The type used depends on the requirements of the customer, but no two customers use the same method of milling.