CNC Machining – Before introducing computer numerical control (CNC), the manufacturing process involved intense human labor, unnecessarily long production runs, wasted material, and fraught with pitfalls. Today technology has dramatically improved the manufacturing process.
The introduction of CNC machining technologies offers a high-reliability level, making iterative processes more automatic. But what is CNC machining? What products can be made from CNC technology? How does CNC Machinery work, and what materials can be used in manufacturing processes that use CNC machines?
This article is a deep dive into what CNC machining is and the basic concepts involved in the process. We will discuss the advantages of CNC manufacturing over traditional manufacturing and CNC’s contributions to modern manufacturing. We will also look at CNC Machinery software. Finally, we highlight what is required of people who wish to train to become CNC machinists and discuss future trends in the world of CNC machining.
Table of Contents
What is CNC Machining?
The abbreviation CNC stands for Computer Numerical Control. CNC machining is a subtractive process of creating custom designs from a workpiece through computerized controls. The process is subtractive in that the product is made by shredding material from an initial part instead of adding material to make a product.
CNC Machinery can be described as a manufacturing process performed by robots. The process has increased productivity as the machine can operate automatically without the operator needing to be present at all times. Coupling nut dimensions are defined in both metric and imperials sizes with unified national coarse pitch
What is the History of CNC Machining?
The predecessor of CNC is numerical control (NC), a process described by the Society of Manufacturing Engineers as “marking the start of the Second Industrial Revolution and the dawn of an era in which the control of industrial machines and processes would go from an imprecise project to an exact science. ”
CNC machining service began as a perforated tape-based technology in the 1940s and 1950s before rapidly evolving into analog and digital technologies in the 1960s. John T. Parsons is considered or known the father of CNC Machinery. He developed digital control, which is the principle on which CNC machining is based. But even before Parsons, the machining technique was invented in 1751. In 1952, Richard Kegg, in collaboration with the Massachusetts Institute of Technology (MIT), developed the first CNC milling machine.
What are the Basic Concepts of CNC Machining?
To understand how CNC works, we need to understand some basic concepts.
Digital Control
This refers to the automatic control of machine tools. These machine tools range from milling to welders, grinders, water jet cutting machine and hydraulic press machines.
Desktop CNC Machining
These are minimalist versions of CNC and are better suited for working on softer materials like wax, foam, and plastics. This type of machining uses smaller versions of CNC machines to make smaller products, mostly by hobbyists.
CAM
Computer-Aided Machining or Manufacturing (CAM) uses software to create code to run CNC machines. To work with a CAM system, you need three things:
1. The first is software that tells the machine the directions to move.
2. You also need a machine that can follow the instructions.
3. Finally, you need to have the postprocessing capability to turn instructions into a language that machines can understand.
CN Code
This is a basic but unique computer language designed for a CNC machine to quickly understand and execute NC code (commonly known as G code). The programmer uses the language to tell the machine how to make something.
Postprocessor
A postprocessor is a translator that converts G-Code written for one CNC machine into code that can be understood and executed by another CNC machine.
How Does CNC Machining Work?
CNC machines operate by having their instructions programmed into software fed into computers using a small keyboard connected to the machine. The CNC system then performs these programmed tasks in the same way as robots.
What are the Different Types of CNC Machines?
Different CNC machines serve different purposes. Some of the most common types of CNC machines are mills, lathes, routers, plasma cutters, and LaserJet cutters.
What can CNC Machines do?
CNC Machinery can produce a diverse range of products from a wide range of materials, including metals, plastics, foam, and wood. As long as a material can be cut, it can be used to make products on a CNC machine. CNC metal lathes can be used for machining round rods, threads, and outer circles. CNC milling machines can process surfaces, keyways, and other irregular shapes. A drill can drill holes.
CNC Software
CNC software is application packages that write G-Code that a CNC machine can read. This software is called Computer-Aided Manufacturing (CAM) or Computer-Aided Design (CAD). This software is responsible for the numerical control of CNC machines. It helps create designs that the CNC machine’s computer program can interpret.
The Different types of CNC Software have Specific Uses:
Computer-Aided Drawing (CAD):
This is used to create 2D and 3D designs and technical documentation.
Computer-Aided Manufacturing (CAM):
Allows users to configure work in branches to meet multiple tasks such as workflow, toolpaths, and cut simulations.
Computer-Aided Engineering (CAE):
Are programs used throughout the development process during the pre-processing, analysis, and postprocessing stages.
What are the Pro’s & Con’s of CNC Machining?
Like any other technology, CNC machining has specific advantages and disadvantages. We take a look at a few below.
Advantages of CNC Machining
CNC machining has a significant cost advantage over traditional manufacturing in that it reduces labor costs. This greatly decreases the margin of error in manufacturing. Additionally, mass production is becoming a much easier task than it ever has been due to its ability to consistently deliver consistent results.
CNC also offers design flexibility that allows the software to be quickly reprogrammed to create entirely new parts or correct errors.
Disadvantages of CNC Machining
One disadvantage of CNC machining is the cost of the initial setup. Businesses may even need to take out loans to acquire CNC technology. If the company can increase its profits through CNC machining, this investment can be recouped quickly.
CNC machining lives on the infallibility of computers. This means that some people using CNC machining systems may ignore the possibility of errors, making it easier for defects to go unnoticed. However, with proper training, this can be alleviated.
Finally, because it is a subtractive process, CNC machining generates waste, which can negatively affect the environment. Nevertheless, waste management processes can be put in place to ensure that the waste produces by manufacturing on CNC machines can be recycled.
How Important is CNC Machining in Modern Manufacturing?
CNC machining has ushered in a new form of modern manufacturing with greater efficiency and precision, offering significant improvements over conventional methods of modern
manufacturing. This means that companies using CNC machining saves costs in labor and time, thus increasing their profitability in the long run.
The CNC has also made manufacturing processes (sheet metal welding, shearing, hole punching, and flame cutting) safer. This is an ideal option for manufacturing as the machines are flexible and can be reprogrammed.
Is CNC Better Than 3D Printing?
3D printing and CNC machining are two manufacturing methods. The essential difference between them is that CNC machinery is a subtractive process, while 3D printing is an additive process. This means that the former creates products by shredding material from an original part, while the latter creates the product.
Which is better between the two methods? It depends on several factors, such as the materials used, the parts’ complexity, the employees’ skills, what it creates, and financial considerations. So one method might be excellent for a specific job and another not.
What Skills do you Need to be a CNC Machinist?
CNC machinists require a minimum of a high school diploma or a GED (General Educational Development) before acquiring CNC-specific skills from technical schools. The GED is a set of tests used to determine whether a person in the United States or Canada has high school academic skills.
CNC machinists, who have certification from institutions like the National Institute of Metalworking Skills (NIMS), have an advantage over those without certification.
What is the Future OF CNC Machining?
As technologies like machine learning(ML) and artificial intelligence(AI) become more popular, CNC machines’ popularity is also expected to increase. Even though some fear that these sophisticated machines will take jobs away from humans, this is usually not the case when technologies improve, as they create more jobs in new fields.
The proliferation of CNC machinery will have benefits for both employees and manufacturers. For the former, the processes are not as complicated, and the security is improved. For the latter, the benefits will increase due to the efficiency. Customers, on the other hand, will benefit from higher quality products.
