Abstract: A new profile modeling machining system is presented, which processes the foam coating on the surface of aircraft to be uniform thickness. 840D CNC, a laser sensor which is installed on the spindle and industrial personal computer are employed to form the system. The feature of the free-form surface is sampled and modeled by CAM software to generate continuous micro-line NC program. NURBS is introduced to NC program post-processing to make the machining high-efficiency and smooth. The main idea of program post-processing algorithm is to construct NURBS curves base on letting inflection points be control points and modifying it by changing the control points, instead of fitting a NURBS curve based on letting measured points be data points, which is time-consuming. The laser is used for precise positioning work piece. Finally, experimental results verify the effectiveness of the processing methods.

Key words: reverse engineering;free-form surface;coating machining;NURBS;tool setting