Centerless grinding may be one of the most misunderstood machine shop procedures. The term “centerless” might lead one to believe the part is simply placed on a machine and somehow the grinding process takes place without out actually securing work piece part properly. However, this is not the case, so let’s look at this method, explore its benefits and discover what it can do for your company.
What Does “Center-less” Mean?
Center-less refers to a process of grinding in which the piece is not held in place by clamps or manually held against a grinding wheel. It is used to grind cylindrical shaped material and can achieve a stunning amount of accuracy. Here is how it works.
A typical center-less machine is an outside dimensional grinder. In standard outside dimensional (OD) grinders the work piece is held between the centers or in a chuck. As the piece rotates against the grinding wheel, material is removed.
With center-less applications, there are two wheels, a grinder and a regulator. There is no need for centering holes or special fixtures. The work piece receives its support when it is placed between the grinder and regulator and sits on a tray or work blade. Because the grinder turns faster, it removes material from the piece while the regulator allows it to rotate. This creates a very smooth centerless grinding process which is even and uniform.
Controlling the Grinding Process
Because the piece is not fixed it is does not have to be set for a specific amount of grinding. In fact, there is no need for special settings because of the high degree of roundness one of these machines is capable of. The process is often used to ensure the roundness of blanks before they are turned into a finished project. However, the location of the work blade or tray is absolutely essential in creating perfect roundness. It must not be too high or low.
Example of Centerless Grinding
Suppose you had a piece of steel pipe and the outer surface was covered with a thin layer of rust. Instead of using chemicals or standard sanding methods, the pipe could easily be fed through a centerless grinder and this would serve two purposes. It would remove all rust and improve the roundness of the outside diameter. This is only one example, of the many applications where centerless grinding is used today. In fact, there are several grinding methods available including CNC grinding.
