Computations for Simplification of Canned Cycles in CNC Programming for Turning Operations

Abstract

Canned cycles are predefined machine instructions stored permanently in the machine controller. These are used while writing part program to perform machining operations that are of repetitive nature. Whenever G & M code for these canned cycles appeared in part program, the controller of the machine calls already stored instructions and executes. However all CNC machines may not have facility to run part programs with canned cycles due to lack of computational facilities. The developed utility in this program allows part programmers to write part program using canned cycles and later on convert them in simplified programs to run on the low cost CNC machines. Present work deals with computations required to convert a canned cycle into linear interpolation based on the machining parameters assigned in that canned cycles. Developed code reads the CNC part program and extracts the desired points from presented canned cycles and perform desired geometric computations to converts it into simple part programs with elimination of canned cycles and writes in another text file in the form of a part program. Developed system is user friendly and made available online for users at http://virtualcnc.iiitdmj.ac.in. It implies a web based online client-server architecture which facilitates user to send their own CNC part programs with canned cycles at server site via internet and get the simplified part program which contains only linear interpolation at their end. Therefore the developed utility in this work can also provide an interface/exchange program for part programs between various CNC machines of different make.