An improvement in the production flexibility and accuracy of rotor milling process employing Finger Cutters

Finger Cutters (FCs) are the recently SRM-developed rotor cutting technology which can be easily integrated into multi-axis flexible milling machines. Opposite to the traditional disc cutters, FC operates inside the rotor body and as a result of that requires much less torque. This opens a new possibility to utilize multi-axis machines in rotor milling process, bearing in mind that they generally have less torque than specialized milling machines. An introduction to FC technology including mathematical modeling, geometrical definition and cutter body grinding has been presented in ICSM2018 conference in Dortmund [2].

In this work, we will present the recent development in FC technology. In particular, we will focus on an innovative method to increase the production accuracy of the FC-cut rotor bodies. This method incorporates an iterative procedure of milling, measuring and adjusting. First, a theoretical target surface, so-called adjustment cut, is defined with a safety margin from the final finished surface. FC removes the material aiming to match the adjustment cut. Measuring the surface and comparing with the adjustment cut, a set of correction factors are calculated for the next iteration. Employing this iterative procedure, a notable improvement in the rotor manufacturing accuracy is achieved while risk for scrap rotors is reduced significantly. (paper)