Involute Tooth Profile Measurement Computing Method Based on VBA

A diagram method is introduced for involute tooth profile base tangent length measurement based on VBA.A involute curve profile is auto-generated through B-spline fitting after inputting a gear basic parameter.On the basis of this profile,the gear diagram is established using AutoCAD functions.From the point of involute reference circle,the base circle tangent line is extended to another tooth opposite flank.Then the across teeth number can be counted,and base tangent length can be directly measured through the gear diagram.This method can check mathematic calculate result and improve efficiency of involute gear dimensional measurement.