Warning track for stability limit

Maximizing machine tool productivity requires knowledge of the stability limits imposed by metal-cutting process physics. Two important work-piece material properties include the cutting force coefficients and the process damping coefficient. The normal component of the cutting force is smaller, but proportional to the tangential component of the cutting force. The measured forces are compared to the programmed chip geometry and the data is typically noisy, or inexact, and varies from one work-piece to another. The dynamic characteristics of the machine are expressed in a frequency response function (FRF), obtained from a measurement near the tool tip when the tool is struck with a hammer and the resulting vibration is measured. The measured FRF is an approximate representation of the machine tool dynamics in the cutting zone.