Evaluation of machining strategies for production of free form surfaces using 3-axle milling

Abstract

The components with formed surfaces are being an important category of the machine parts. They are applied in the most of industrial branches. In order to produce such type of machine parts it is necessary to harmonise the contradictory requirements, e.g. the minimal production time, the required precision of dimensions and the surface quality. A relevant role is playing the chosen machining strategy specified for the above-mentioned demands, namely during the finishing operations. The most important evaluation criteria for selection of the concrete CAMsystem are: the disposable machining strategies, visualisation level of the proposed process and recognition of the virtually machined surface. The term "machining strategy" represents the pre-defined (and in the CAM-system also the available) tool trajectories that are optimised for machining of the variable formed surfaces so that the work-piece could be machined most effectively. A projection and evaluation of the cutting trajectories is not a simple process. There are at disposal many professional articles, which started to be published after occurrence of the first software solutions created as a support of the NC-software development. A development of the new strategies, i.e. the projection and optimisation of the new methods for control of the tool movement on the machined surface, is a multidisciplinary area, which requires knowledge from the theory of machining, descriptive geometry, informatics and also mathematics. The standard machining applications are such strategies, for example, that are able to optimise the cutting conditions in order to achieve a constant loading of the tool and in this way they enable prolongation of the tool durability as well as improving of the manufactured surface quality. Another important area is also evaluation and comparison of the existing strategies because the proper choice of them can help to reduce the machining times and the tool wear-out due to a shortened length of the tool operational path. This fact has a relevant impact on the production efficiency. The main topic of this paper is a description of the quality analysis focused on a surface area, which was machined by means of the various milling strategies and at the same time there were monitored deviations of the machined surface in comparison to the original 3D-model of the freeform surface area. This matters is analysed in [1], [2], [3], [4]. © 2013 Published by Manufacturing Technology.