Three-Dimensional Endmill Dynamics: Modal Development and Experimental Validation

In this paper the three-dimensional dynamic behavior of macro-scale milling tools is modeled using the spectral-Tchebychev technique while considering the actual fluted cross-sectional geometry and pretwisted shape of the tools. The bending and torsional behavior of three different fluted endmills is compared to finite element predictions and experimental results obtained using impact testing with free-free boundary conditions. The percent difference between experiment and the spectral-Tchebychev method predictions is shown to be 3% or less for all three tools while considering the first six bending modes and first two torsional modes. For the same modes, the spectral-Tchebychev and finite element model predictions agreed to better than 1%.