NC data generation for 4-axis machine tools equipped with rotary angle head attachments to produce variable pitch screws

A kinematic model to generate the NC data for 4-axis machine tools equipped with rotary angle head attachments has been developed in order to produce a double threaded variable pitch screw. The 4 × 4 homogeneous transformation matrix is employed in the derivation of the ability functions of the machine tool and in the generation of the desired cutter locations. NC data equations are obtained by equating the corresponding elements of the ability function of the machine tool and the desired tool location matrices. The machine tool settings for a screw are investigated and then this screw is machined as an illustrative example. This general methodology is applicable to various types of cams possessing conical or cylindrical meshing element(s). It also combines the activities of design and manufacturing, thus making the production process more flexible, automatic, and controllable.