Cutting Force Estimation by Measuring Spindle Displacement in Milling Process

A cylindrical capacitive displacement sensor (CCDS) was developed and applied for monitoring end milling processes. Dynamic characteristics of a spindle-assembly were measured using the CCDS and a designed magnetic exciter. The technique to extract the spindle displacement component caused only by cutting from the measured signals using the CCDS was proposed in the paper. For the quantitative estimation of dynamic cutting forces from the measured signals, a mechanistic model considering tool deflection, which is derived from the dynamics of the spindle tool system, was proposed.