Automated NC program generation for hole drilling and swarf machining by 5-axis indexing machining

Abstract

This study proposes a method for extracting the machining region machined by swarf machining and hole drilling from a Standard Triangulated Language (STL) data exported from 3D CAD and automatically generating a tool path. First, a method is proposed for extracting the machining region and obtaining geometric features, such as slope, curved surfaces, holes, and pockets, from the STL data exported from 3D CAD. The STL data uses only triangular mesh data and drops all information, which is necessary for extracting the removal volume for the machining and geometrical characteristics. Then, a half-edge algorithm is proposed that clarifies the connection relationship between planes by integrating triangular meshes of the same plane in a model in STL data and realizes automatic extraction of machining regions through the analysis of shape data. Subsequently, a method is proposed to determine the 5-axis indexing posture and generate a tool path according to the geometrical features of the machining region. A machining experiment was conducted to validate the effectiveness of the proposed method. As a result of the machining experiment, it was confirmed that the tool path automatically generated from the STL data exported from 3D CAD can be machined without any problems and with a practical level of accuracy.

Keywords

• computer aided manufacturing (cam)
• 5-axis machining
• swarf machining
• hole drilling
• nc program generation