From CNC Programming Techniques: An Insider’s Guide to Effective Methods and Applications

It is much easier to calculate the absolute XY coordinates for a simple contour, such as a rectangle, but it is much harder to calculate points where the contour includes angles and partial radiuses. These parts are usually programmed with the assistance of a CAD/CAM system (CAM), but if such system is not available or in other situations, the CNC programmer must resort to the old fashion way, by using a pocket calculator. Most calculations will be using trigonometric functions, but knowing the basic arithmetic and algebraic operations, knowing formulas, being familiar with solving triangles is still the major requirement. This chapter will present some techniques that have proven to be suitable for solving a majority of problems associated with calculation of more difficult contour points.

Tools and Knowledge

Any tool can only be used correctly if the user has a sufficient amount of knowledge about the purpose of the tool and how to use such a tool. In CNC manual programming, we are talking about three major tools pencil, paper, and a calculator. An old cartoon has also shown a fourth tool a very large eraser. Of course, in these days, pencil is most likely replaced by a text editor (even Windows Notepad will do in an emergency), and actual printing on paper is not always necessary, as the program can be transferred to the control system via a cable, using DNC software. Eraser is part of the editor, and Windows even provide a simple calculator. In practice, a physical...

Products & Services
Computer-aided Design and Computer-aided Manufacturing Software (CAD/CAM)
Computer-aided design and computer-aided manufacturing software (CAD/CAM) is used in mechanical, electrical, and electronic design; simulation, drafting, and engineering; and design analysis and manufacturing.
CNC Routers
CNC routers are computer-controlled machines that are capable of cutting complex two-dimensional (2D) and three-dimensional (3D) shapes with router bits that spin at high speeds.
Tool Grinders and Sharpeners
Tool grinders and sharpening machines are specialized for tool, die, punch, cutter, blade and drill point sharpening, grinding, honing, finishing, resharpening, refinishing or regrinding.
Math Calculation Software
Math calculation software is used to perform mathematical calculations. These programs provide general core calculations as well as graphical analysis that can be used in science, engineering and technology.
Computer Numerical Control Software (CNC)
Computer numerical control software (CNC) is used to create tool paths for CNC machine control systems, or to turn a personal computer (PC) into a CNC controller.

Topics of Interest

Overview In the previous chapter, the main focus was on evaluating a part contour and establishing contour points necessary to develop a suitable toolpath. This chapter continues that subject, with...

OVERVIEW Writing a CNC program is the final result of manual programming. This last step requires a sheet of paper, or many sheets of paper, that contain the part program. Program itself is composed...

OVERVIEW Writing a CNC program is the final result of manual programming. This last step requires a sheet of paper, or many sheets of paper, that contain the program. The program is composed of...

Stock Allowance In a machining environment, stock allowance is a term that defines the amount of material left for finishing after rough cutting had been completed. Although it seems a subject simple...

OVERVIEW The contour of a part - also known as a profile - is normally programmed for milling applications by establishing the depth in the Z axis first, then moving the cutting tool individually...