Chatter A phenomena that produces periodic marks on the workpiece and sometimes associated with audible sounds during grinding. Caused by vibrations that originate with the rotating grinding wheel, spindles, slides or other components of the machine tools.
Early wheels were simple wooden disks with a hole for the axle. Some of the earliest wheels were made from horizontal slices of tree trunks. Because of the uneven structure of wood, a wheel made from a horizontal slice of a tree trunk will tend to be inferior to one made from rounded pieces of longitudinal boards.