An Optimization Post-Processing Module For Complex Tool-Tip Milling Operations

This paper presents an optimization post-processing module allowing to improve and to optimize tool-tip milling operations. Moreover, this module verifies and insures milling feasibility of a complex tri-dimensional shape. During such situations, the tool is in contact with the workpiece through a point located on its ball-end mill. Knowing that a relatively large variation of the tool orientation does not necessarily change the resulting workpiece geometry, then the postprocessing module can be formulated as an optimization problem. The tool orientation is computed to be as close as possible to our preferred orientation together with its joints as far as possible to the joint limits, and obviously, subject that the tool-tip is following the required trajectory. The module has been implemented for the Huron KX8-Five milling centre. Several surface shapes have been post-processed and verified in simulations with VERICUT, among which four parts have effectively been machined. Our optimal module produced a CAM program which could then be transferred into a CNC milling machine and this program succeeded in machining a complex workpiece which would normally prove unfeasible with a classical approach which usually maintains the tool normal to the surface without exceeding the joint limits.