Shape-adaptive CNC milling for complex contours on deformed thin-walled revolution surface parts

Thin-walled revolution surface parts are extensively used in various fields. Owing to their low rigidity, there is an inevitable deformation caused by the blank forming and clamping processes. This makes high-precision machining of parts with complex contours for industrial applications challenging. To solve this problem, a shape-adaptive milling method for complex contours on deformed parts is proposed. First, the real geometry of a deformed part is acquired by a developed contact-type on-machine measurement (OMM) system. Subsequently, an orthogonal arc-length mapping is mathematically proposed to establish a one-to-one correspondence between the nominal and real surfaces. The method of adjusting the tool path is based on this correspondence is discussed in detail, using which the nominal tool path can be adjusted to adapt automatically to the shape change of the real part. In addition, the methods of refining the tool path, such as eliminating the overcuts and undercuts and reorienting the cutter orientation, are also presented for achieving a good milling quality. Finally, the experiments of milling complex pattern contours on thin-walled bangles, which are typical revolution surface parts with low rigidity, are presented, and the simulation tests on a general revolution surface are also conducted. Experimental results illustrate that the proposed method can produce clear and complete contours on the deformed revolution surfaces.