March 9, 2017
An Introduction to CNC Machining
1. CNC stands for ‘Computer Numerical Control’
CNC machining is a process used in a wide range of manufacturing applications, but what exactly is it and how does it work? CNC stands for ‘Computer Numerical Control’ and refers to the use of a computer to control the action of a machine tool such as a lathe, mill or router. CNC machining can be used to machine parts from many different materials such as a wide range of metals and plastics.
2. CNC machines are programmed with a language called G-Code.
CNC machining uses special CNC software and a programming language called G-Code in order to control every aspect of the machine tool’s movement in order to manufacture an object. G-Code instructions control the speed and positioning of the cutting tool in relation to the work-piece, the feed rate of material into the tool and many other factors.
3. It all starts with CAD
The process generally starts with either a 2D CAD (Computer Aided Design) drawing or a 3D CAD model. The G-Code is then derived from this and a trial run is performed to test the program. This is known as “cutting air” and is very important in order to avoid any mistakes which could result in a damaged work-piece or cutting tool. If the test is satisfactory then the program can be run to machine the real part.
4. CNC offers precision and repetition
CNC machining can be used to make complex 3-dimensional shapes as a single piece. It allows greater precision than manual machining, and most importantly, it is repeatable. The same CNC program can be used again and again to manufacture multiples of the same part.
5. With CNC you can manufacture any part you can imagine
CNC machines are typically capable of moving the cutting tool and/or the work-piece in several different axes of motion. A 3-Axis CNC machine has movement in the X, Y and Z axes to produce 3 dimensional shapes and is the basic model. More advanced 4-Axis CNC machines introduce a 4th rotational axis of motion parallel to the X axis to enable production of even more complex objects. 5-Axis and even 6-Axis machines are also available, which make it possible to manufacture almost any shape which can be imagined.