In a production grinding operation, waviness on the part surface is a potential clue that the machine or process has developed a vibration problem. The effect might be seen in inspection, or if there is a lapping or polishing step, it might cause more time to be spent at this step removing these waves. According to grinding wheel manufacturer Norton Saint-Gobain Abrasives, this is the point at which shops almost always attempt to solve the vibration problem by making some simple change to the process. And that’s a pretty good approach.
Indeed, those waves on the surface, often called chatter, could indicate the appropriate fix. (Others use “chatter” to refer to regenerative waviness. The use here is not that specific.) On a part machined on a surface grinder, for example, vibration frequency (cycles per minute) is equal to the work speed (inches per minute) divided by the distance between two consecutive chatter marks (inch). Find the vibration frequency using this relationship, and if it matches the rotation speed of the grinding spindle, then this indicates that the grinding wheel, wheel flanges or the grinding spindle itself is a likely culprit. Change the wheel, tighten the flange bolts, or perhaps just change speed, and that much might be enough to cure or control the vibration problem.