Parameter Space Decomposition for Selection of the Axial and Radial Depth of Cut in Endmilling

Abstract

Feeds and speeds for conventional endmilling operations have been empirically investigated and extensively tabulated 1. However, the selection of the geometric cutting parameters, the axial and radial depths of cut, remains an inexact science. Observation of mechanistic process simulation predictions reveal a relatively complex topology resulting from the multiple cutting flutes of conventional endmilling cutters as the axial and radial depths of cut are varied. A partitioning approach is presented that explicitly enumerates the transition events due to the entrance and exit of the individual cutting flutes. The resulting simplified optimization formulation permits selection of the axial and radial depth of cut that most efficiently satisfy critical simulation predictions such as maximum cutting force or form error. Case studies are presented illustrating the application of the method to select the cutting parameters in climb milling. The optimization objective in the case studies is to maximize the material removal rate, subject to the process induced constraints. Results suggest that operating at the extremes of either axial or radial engagement may in various instances be preferable to more conventional combinations of depth and width of cut. Certain regions of the parameter space are observed to be necessarily sub-optimal relative to particular planning constraints, while other regions are found to contain particularly attractive operating points.