Abstract: Aiming at the linear-interpolation shortage of tangency discontinuities and too many interpolation-points along tool paths, an optimization strategy of tool path is presented for 5-axis high speed machining prostheses based on stereo lithography modeling. In this strategy, unnecessary interpolation points are removed, consequently all the tool paths are simplified; the surface of envelope cutter orientation is smoothed by adopting the advantages of ruled surface; a new method of spline interpolation is put forward to support Heidenhein CNC system. On the basis of these, G-codes generated by linear-interpolation are successfully transformed into Spline-codes. Using Vericut NC simulator, molar crown prostheses are manufactured. The test results show that the profits of the optimization strategy concern the reduction of machining time as well as the quality of the machined parts compared to those of linear-interpolation. Indeed, the tool-path continuity avoids the appearance of marks and facets.

Key words: computer application, spline interpolation, tool-path optimization, STL modeling, prosthesis