Automatic tool selection for milling operations Part 2: tool sorting and variety reduction

The first part of this paper introduced a procedure for rapidly calculating optimized cutting data for all the feasible tools for a given milling oper ation. Having produced this list of tools with associated optimized cutting conditions, the preferred tool is selected by sorting the list by a compos ite objective function incorporating a combination of four desirable condit ions: maximum metal removal rate, maximum tool life, minimum overall cost a nd minimum overall cutting time. These four criteria are normalized by a co nstant multiplier and prioritized by user-defined weighting coefficients. T he tool selection procedure is implemented in software with a graphical use r interface. The system includes material data for more than 750 ferrous al loys and specifications for 35988 possible holder/insert combinations. Seve ral examples are presented to demonstrate the capability of the system and the subtle interplay of technological constraints that makes optimized tool selection a difficult process to perform manually. This automated procedur e offers consistent selection of tools with efficient cutting data that can produce considerable reductions in machining cost when compared with non-o ptimal solutions. This tool selection procedure is designed to select tools and associated cu tting conditions for single milling operations. As many machining centres h ave a limited number of tool positions available for automated tool changin g, it is possible that the optimal set of tools for a given component is no t the set of tools that are optimal for each operation considered singly. A post-processing method is presented which rationalizes a set of tools so a s to reduce the number of unique tools with the minimal decrease in perform ance when compared with the set of individually optimized tools.