C-Space-Based Toolpath Generation for Five-Axis Controlled Machining with Special Tools

Abstract

This paper describes a method for generating toolpaths based on machining strategies for five-axis controlled machining using special tools. Traditionally, most toolpath generation studies focused on ball-end mills, proposing strategic methods to achieve high-quality machining while avoiding tool interference. Recently, special finishing tools with large cutting edge radii have gained interest for achieving higher machining efficiency. These special tools can produce smooth finished surfaces even with large pick-feed widths, leading to higher productivity. However, unlike conventional machining with ball-end mills, five-axis controlled machining using special tools lacks standardized work design procedures. This study proposes a generic tool-geometry data format for defining special tool geometries and a method for generating toolpaths using this data format. This method strategically treats special tools as conventional ball-end mills. Consequently, five-axis controlled machining for new tool geometries can be achieved using existing operational procedures. To generate toolpaths, this study utilizes a two-dimensional configuration space (C-Space). For special tools with multiple cutting edge radii, the relationship between the tool posture and cutting edge contact point is clarified by mapping the cutting edge radius information onto the C-Space. By employing this mapped cutting edge information, we can determine the interference-free tool posture corresponding to the chosen cutting edge section based on the machining strategy. Finally, the paper presents machining simulations and experiments conducted to confirm the effectiveness of the proposed method.