Based on CNC spiral bevel gear machine

machining coordinates is set up

cradle radial setting and roll ratio polynomials are proposed. Considering contact lines and transmission errors

the polynomials are put into tooth contact analysis process to study tooth profile correcting rules. An example shows that lengthwise curvature modification can be achieved without changing cutter diameter

contact lines and transmission errors can be controlled more easily. The research can enrich tooth profile control means

and develop the machine capabilities dramatically.