Design and manufacture of a new micro ball end milling with helical cylindrical structure

According to the characteristics of micro cutting tools and their application requirement, a new design method of micro ball end mill with helical cylindrical structure is proposed. It changes the cutting edge of ball end milling from the complex space curve into a plane curve. Based on the geometric structure characteristics of the new designed micro ball end mill, the cutting tool structure is optimized with respect to the manufacturing process. Through the analysis of the principle of tool grinding process, the designed tool is fabricated in micro NC grinder. The cutting performance of the new designed tool is investigated through cutting experiment compared to the cutting performance of traditional spiral groove ball end milling and elliptical ball end mill. The results indicate that the designed micro ball end mill can achieve higher cutting edge strength, which can meet the micro cutting requirement for hard brittle materials. In the meantime, the complexity of cutting tool preparation can decrease dramatically.