PROGRAMMING METHODS

CNC part programming may be accomplished in different ways, such as

Manual Part Programming: Manual part programming is the oldest method and still quite popular. This technique requires the programmer to examine a part drawing then ‘manually’ calculate all tool paths. This information is recorded on a manuscript. A punched tape is prepared from the manuscript.

Computer Assisted Part Programming: In computer assisted part programming, much of the tedious work required to calculate tool offsets, partial arcs, and the geometry of the part, is performed by the computer. When using computer assisted part programming, the programmer utilizes a high level language to describe part geometry and cutter path with respect to the geometry, then the computer performs all necessary calculations and generates tool path information. This tool path data is then post-processed into the format required for a specific CNC machine tool. For complex parts, computer assisted part programming may be necessary and the savings in programming time can be substantial.

Computer Aided Drafting/Computer Aided Manufacturing: This method of programming machine tools is sophisticated and growing in popularity. As CAD/CAM software systems become more user friendly, inexpensive, and reliable, more and more manufacturers are turning to CAD/CAM for part programming. Essentially, CAD/CAM enables a programmer to manipulate CAD data so CAM software is capable of understanding the data. Once properly manipulated, the CAM software performs all necessary calculations and generates CNC tool path data that are made to part-processed for a variety of machine tools.

Conversational and Shop Floor Programming: Conversational programming is an interactive method of generating CNC code. The CNC programmer or machine tool operator answers questions and provides data about tool paths when prompted by a conversational programming software system. These answers to questions and associated data are translated into a CNC program for a particular machine tool. Often these conversational systems reside on the machine tool controller and the interaction (programming) is done on the shop floor, hence, the term shop floor programming. This method of programming is generally restricted to relatively simple geometry.

Parametric Programming: An enhancement to the methods above more so than a method in and of itself, parametric programming software systems enable the programmer to describe part geometry using variables. Once described, entering specific values for the variables that uniquely identify the part generates an actual tool path CNC program.