Exact tool sizing for feature accessibility

This paper presents an algorithm for calculating the volume of a 2D-profile , accessible by a given diameter of milling cutter. The method is independe nt of the generation of cutter tool paths, and exploits facilities commonly found in kernel modellers. Exact results are obtained despite the simplici ty of the procedure. As a proof of the concept, the algorithms have been im plemented in the Heriot-Watt University feature recogniser as a pre-process or for a part programming system. The aim of these algorithms is to assist and optimise the selection of multiple tools for the machining of complex c omponents. The methodology has applications in process planning research wh ere it is currently common to assume that a single tool will machine each f eature. Although cutter selection is a critical step in planning the manufacture of components, computer-aided process planning (CAPP) systems rarely make any attempt to analyse the tradeoffs involved. Perhaps this is because, tradit ionally, exact tool accessibility calculations have been viewed as a side e ffect of generating a cutter tool path. Consequently, accessibility calcula tions are not carried out explicitly but they appear implicitly in the resu lts of a complex geometric algorithm (j.e. cotter path generation). Because this implicit checking of tool accessibility is carried out downstream fro m the higher-level reasoning about set-up and sequencing, the results are g enerally available only after a detailed process plan has been generated.