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The purpose of this thesis is to develop a method for four-axis rough machining of the Roller Gear Cam ( R.G.C. ). This methoc allows manufacturers to choose four-axis milling machines in the rough machining stage of production, thereby decreasing the cost of implementing the five-axis machining center.
First, based on the relationships between cutter and roller and the conjugate movements between roller and R.G.C., the direction of the tool-axis and the position of the tool-tip are calculated by coordinate transformation. To avoid overcut between the cutter and the design surface, the surface interference checking is performed and used as a basis to select the suitable radius of the cutter. In the case of interference between the machined surface and the design surface, a method for the cutter withdrawal is proposed to solve the problem.
Then, a four-axis post-processor program is developed to convert the cutter location file to actual NC code. The methods proposed in this study were all proven through solid cutting simulation software and through a trail cut with model material.
For the industrial example in this thesis, the time using the five-axis machine by the proposed methods is 30% of the original roughing time using the five-axis machine. So it decrease the machining cost. At the same time, in this study, the four-axis machine removed 87% of the roughing material, so the five-axis machine had to remove only the remaining 13%. The economic value of rough milling for the R.G.C in the four-axis machine by the proposed methods has been confirmed.
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