Today's industrial practice shows that - in contrast to the past years, where gears were designed as standard as possible - machine parts are constructed on the basis of selecting non-standard parameters. This is because producers protect themselves against making additional parts from local suppliers for much less money by customers. The paper presents a geometric and strength analysis of an exemplary spur gear, which works as the second stage of a bevel-helical gear in the coiling mechanism of a multi-module machine producing bonell springs for mattresses. It was checked whether the transmission could be redesigned in such a way as to make its geometry as complicated as possible while maintaining the appropriate strength properties. Finally, there are graphs that can be helpful in this type of reconstruction process, and the subsequent stages of this work can be treated as a kind of algorithm for the discussed conversion of geometric parameters of the gear.