In the cam programming, optimization rough metal cutting is the most important step. According to a particular combinations of tools and materials, machining table recommended cutting depth and span is assumed that you use the same span the entire tool paths for roughing cutting. However, if your path involves slotted mobile, or accidentally fell into fillets into, then the tool may encounter more material than expected.      Only when all sides need to cut materials are open when using a simple bias processing model is ideal. If you need to process the wall and you are ready for roughing the area adjacent to the processing mode then this may result in the entire material slotting tool (Figure 1). A better approach is the choice of parts along with bias mode. This processing mode is started from the part of the wall surface, and gradually inward processing, it can avoid the slot. Even if the tool path includes many fast cutting exercise, but because this model allows to increase the span, the overall processing time can be reduced. The best way is to use cycloid processing mode, which can monitor the amount of cutting tools, and maintain a stable threshold.