An analytical representation of HFT （Hypoid Formate Tilt） hypoid pinion fillet surface has been advanced. On this basis

an accurate model of pinion tooth has provided. By the numerical simulation on computer. An iterative approach for determining the pinion machine-tool settings by using the local synthesis and pinion tooth model has been developed

which made the real tooth height and required meshing quality be satisfied simultaneously. Further

an accurate test for undercutting and interference with gear top has been combined with above mentioned approach to make up a perfect program for designing

analyzing and simulating the hypoid gear drives.