CNC Machining and What it’s Used For
Computer numerical control, or CNC machining, is a computer-aided, high-accuracy manufacturing process. Pre-programmed CAD software is used to automate the controlled machining. The main advantage of CNC machines is their ability to run unattended during the machining cycle and manufacturing process, allowing the operator to carry out other tasks elsewhere.
It reduces human error during the controlled machining process and allows for high accuracy manufacture of the different parts. Another benefit of CNC machining is consistent and accurate workpieces.
The CNC machining operations of today benefit from not only high accuracy machine tools and code controls, but also the ability to repeat multiple manufacturing processes on separate occasions. The flexibility of CNC programming easily allows CAD files to be tweaked and changed to produce multiple different parts.
All CNC machines work based on a 3-axis motion control process. The X, Y, and Z axes are positioned with high accuracy along their length of travel. Most axes are linearly positioned, but some are also rotary, meaning that they move around a circular part. CNC machines work with a range of motion actuated by servomotors and guided by computer-aided code controls.
Also, CNC Machines are high-precision electromechanical devices that can manipulate cutting tools around 3 or 5 axis through a computer program to make complex parts. CNC Machines can be controlled by either writing the g-code for the machines, using a CAM (computer-aided manufacturing) software that automatically writes the g-code from a 3D computer model or through conversational programming which is done at the machine.
CNC machining is a subtractive process meaning that it removes material to make the desired part, unlike additive processes such as 3D printing. The machines remove material from blocks of material (called blanks) by drilling, lathes, and milling and can change tooling and bits during machining.
CNC machines can be used on a variety of materials from ceramics to polymers but are more commonly used on wood and metals such as aluminum, steel, and titanium. These machines are much quicker and more precise than manual machining methods with tolerances up to ±0.001mm!
What Skills are Required for CNC Machining
That is to understand the mechanical functioning of the machine and to be able to control the machine through programming.
CNC Machine Knowledge
Understanding the mechanical functioning of the machine can have a big impact on the quality of the finished part both aesthetically and structurally. Understanding the functioning of the machine includes knowledge about: tooling; feed speeds; how to calibrate a machine; how to secure work in the machine; and most importantly, how to safely operate the machine.
Common CNC Machine types:
3 Axis Machines:
Continuous 5 Axis
Indexed 3+2 Axis
CNC Programming Knowledge: G-code and CAM
manually programming a CNC machine job is uncommon with the development and widespread use of CAM software.CAM automatically writes the g-code for 3D computer models. So if you using a CAM software like Fusion 360 with an Arduino CNC machine, you may never have to touch g-code.
a professional CNC operator will work mainly with CAM. CAM requires the operator to have expert knowledge of the machine being used and the right tools to use for the job.
CAM is a great tool that has increased the efficiency of the CNC machining manufacturing process, it is still often the case that CAM does not produce the desired result and the g-code has to be edited manually by the operator.
Popular CAM Software: