Design of flexible hole milling cycles on CNC machines

The paper describes the stages of designing the technological end hole milling cycle and presents the developed CONICALINT software, which generates a G-code with argument lists used to call up a technological cycle from the CNC system memory. The developed algorithm for the technological end hole milling cycle has a branched structure, since it can choose between two methods for calculating the internal cycle parameters and two milling methods - climb down and climb up. The calculation of the internal technological cycle parameters consists of calculating the coordinates of the points necessary to construct the helical path of the cutting tool, as well as the maximum permissible value of the helical pitch within a given set of input parameters. The initial calculation data are represented by thirteen parameters characterizing the geometry of the cutting tool, the geometry of the required machined surface, as well as the parameters that determine the milling method and the method for calculating the cutting mode and the starting points of the cutting tool path. We identified eight boundary conditions that determine the permissible values of the input parameters. Based on these conditions, we designed a system of inequalities with a set of error messages displayed to the user if any of the input parameters is entered incorrectly. The developed G-code of the technological cycle subprogram for a CNC machine calculates the tool movement both along a helical and a conical helical path, depending on the input parameters, which allows using it to program cylindrical and conical hole milling. The developed CONICALINT software is a visual addition to the developed technological cycle of hole milling. The developed CONICALINT software is a visual addition to the developed technological hole milling cycle, which allows generating a control G-code with a set of twelve arguments.