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Although flat-end multi-axis milling has been proven to be more efficient than ball-end machining for more than twenty years, dedicated tool path generation and planning algorithms have been seriously suffering from insufficient intelligence because they originate from ball-end algorithms and do not consider issues attributed to the flat-end shape of tools. This research work describes the development and implementation of new algorithms designed for tool path planning and generation aiming taking machine kinematics into account. The developed components are founded on prototype software that can handle STL geometry for robust computation of tool path tracks and interference-free tool postures. This STL kernel was also extended with support of facet machining status to enable machining simulation. In addition to the kernel, three different components were developed to facilitate optimization of tool inclination, material removal simulation, and tool path planning. First, two tool path optimization methods were elaborated to perform minimization of machine tool rotations in reasonable computation time. Second, a novel material removal simulation based on accurate estimation of swept sections has been introduced. Third, tool path planning algorithms integrating the developed material removal simulation allow efficient tool path generation with reduced machining strip overlaps and dynamic step-over between adjacent tool path tracks. This integration has also given an opportunity to introduce two strategies. First strategy implements the cutting plane approach to slice STL surfaces and generate zig-zag-like tool paths with intelligent selection of tool path tracks directions. Second strategy generates contour-like tool paths, going inwards from a workpiece outside, resulting in machined surfaces with predictable scallop height. This research highlighted and resolved several flaws in existing algorithms. First, estimations of machining strip widths derived from a single posture are almost surely incorrect in a case of five-axis machining. Therefore, a new approach taking several postures into account has been developed and implemented. Second, regardless of the dramatic influence of machine tool kinematics and CNC behavior onto the actual shape of a machined surface, machine tool characteristics are not considered by the existing material removal simulation algorithms. Thus, in this research, tool motion has been interpolated in machine coordinates. The developed methods can be smoothly integrated with themselves and other CAM software. Eventually, these methods are believed to assist CAM programmers in generating efficient tool paths in an automated manner. nrpages: 158 status: published

In this paper, a novel approach for five-axis toolpath planning taking tool swept volumes and machining performance into account has been introduced. The toolpath generation is based on cutting planes slicing a meshed surface to provide toolpath tracks on the surface. The cutting planes can be orthogonal to each other, and positions of these planes are computed consequently so that a next iteration considers regions machined at the previous iterations. The developed algorithm alternates between several candidate tracks to ensure that a track with the best performance, which may be formulated variously, is selected. Each candidate track is computed to result in a tool swept volume that completely removes stock material between the toolpath track and the boundary of the un-machined region. Several planning strategies can be applied in order to obtain a machined surface with scallop height not exceeding a given value. ispartof: 1st International Conference on Virtual Machining Process Technology location:Montreal, Canada date:28 May - 1 Jun 2012 status: published

This paper describes the development of a five-axis tool path generation algorithm for the machining of complex shaped parts using flat-end tools. In order to reduce the machining time and to ensure optimal quality, the step-over is optimized in each tool contact point. This step-over calculation is obtained through the integration of a newly developed algorithm for material removal simulation. The latter is performed by calculating swept volumes which represent tool motions interpolated according to the machine kinematics. The developed algorithm has been implemented for contour like (spiral) strategies and validated through the machining of an industrial example. 2012 CIRP. ispartof: CIRP Annals. Manufacturing Technology vol:61 issue:1 pages:139-142 status: published

ispartof: pages:133-152 ispartof: Proceedings of the MTTRF 2008 Annual Meeting pages:133-152 ispartof: MTTRF 2008 Annual Meeting location:San Fransico, USA date:1 Jul - 2 Jul 2008 status: published