Tool path modification for optimized pocket milling

Abstract

Many operations in CNC milling tasks are performed using pocket milling which has two main types of tool path trajectories, contour parallel path and direction parallel path. Hence there have been a lot of works on geometrically efficient algorithms to generate tool paths. Although the conventional tool path obtained from geometric information has been successful to make a desirable shape, it seldom considers physical process concerns like cutting forces and chatters. In order to cope with these problems, an optimized tool path, which maintains as constant MRR as possible in order to achieve constant cutting forces and to avoid chatter vibrations at all time, is introduced and the result is verified. Additional tool path segments are appended to the basic tool path obtained by geometric shape by using a pixel-based simulation technique. The algorithm has been implemented for two-dimensional contiguous end milling operations, and cutting tests are conducted by measuring spindle current, which reflects machining situations, to verify the significance of the proposed method.

Keywords:

• Pocket milling
• Contour parallel tool path
• Direction parallel tool path
• Constant cutting force
• Material removal rate