Shoe Last Surface Reconstruction And NC Machining Emulation

To improve the manufacturing ability of shoe last in our country and enhance the market competition of shoe last, this paper discusses the changes of the manufacturing technology of shoe last by using CAM(Computer Aided Manufacturing) and the numerical manufacturing method from data processing of shoe last to producing the track of NC machining, and built the CAM software system of shoe last based on WINDOWS.The paper introduces data type of shoe last and the method and feature of shoe last surface data detecting. It puts forward data saving method and format of shoe last detecting data file. Because the noise in detecting data of shoe last has bad effects on last's surface and machining, it advices two smoothing methods of subsection N-points mean value filtering and least square patching fitting. These two methods can achieve data smoothing based on not destroying the characteristics of shoe last surface and can better satisfy the smoothing request of shoe last surface. But subsection N-points mean value filtering is much more simple and efficient.Because the detecting datas are the center of the measuring head , they should have appropriate management in order to obtain the actual locations of the scattered datas of shoe last surface. The paper discusses the varying tangent points between measuring head surface and shoe last, and puts forward a data management method, and builds the spatial coordinate system of measuring head surface, and deduces its revelance spatial equation. At last the calculation of shoe last surface scattered datas are changed into abtaining the intersect points between lines and measuring head surface. A method of numerical analysis is used to attain the conclusion so as to acquire the location of the shoe last surface scattered datas.During NC machining, because of the varying tangent points between milling cutter rotary surface and shoe last surface, the paper advices a method of least distance to calculate the cutter center, and builds the spatial coordinate system of milling cutter rotary surface, and deduces its relevance spatial equation. At last the calculation of cutter centers are changed into obtaining the intersect points between lines and spatial surface. A method of numerical analysis is used to solve the problem. Bicube B-Spline is applied to attain cutter centers of NC machining.Based on the ahead discussion, VC++ and OpenGL are used to develop a shoe last emulation software system. It includes detecting datas management module and data emulation module. Users can deal with data management through this software system. Reliability of NC machining is improved.