In project design it is needed t0 draw 80me specific curves.General CAD software does not offer the simple method drawing this kind of curves.User has to do 80me advanced developments to meet the need.On the basis of analysis about the gear shape.a menu command has been developed to draw the gear in the AutoCAD 2000 with VBA.It provides a convenient tool to.draw the gear for engineers and a complete example of advanced development for the u8er8 of AutoCAD200.