Modeling of Hob Cutter Using Comparable Gear Rack

The sequence to create a parametric model of hob cutter is considered in the paper. Parametric modeling has a number of features associated with the permanent rebuilding by changeable parameters. There are limit values which can have self-intersections, new or spurious edges that do not exist in the design of a specific model of a hob cutter. Parametric modeling also involves the creation of a friendly interface for operator interaction with the model. It was constructed in NX, the dialog box was created in the application "template Studio products." It was decided to split the design into 3 components. The first is the fully automated calculation based on the basic parameters of the wheel. The second is the ability to edit the parameters of the model based on the applied in the specific manufacturing conditions. The third is a summary table of all the resulting parameters. The calculation formula of the flank and clearance lug in hob cutters are presented in the analytical form on the basis of equivalent gears. The equivalent gear wheel is calculated through the ratio of the involute function of the end angle to the involute function of the original contour angle. The equivalent spur wheel with new module settings and diameters is obtained, which is the classic calculation of the hob cutter. A method of development based on the equivalent rack is presented. The use of equivalent elements for simplicity of development is common, but the approximation of the profile should not be greater than the tolerance on the modeling, which is 30-50% of the tolerance on the measurement. The paper presents the results of a measurement using three-dimensional optical scanner ATOSIII. Rev. 02, which was not suitable for accurate measurement of the elements of the cutting tool in view of the insufficient stability of the measurement. The main drawback of measuring a three-dimensional optical scanner was the impossibility of introducing corrections in the further manufacture and regrinding the resulting hob due to the random nature of the distribution of measurement errors.