CNC Machining: Your Beginners Guide

In an effort to maximize efficiency and reduce costs throughout the manufacturing industry, research and development in the field have prioritized machine automation in order to drive innovation. This has resulted in machines becoming smarter and more efficient, and capable of operating at length with very little input from human operators. One manufacturing process that has risen out of this push towards automation is computer numerically controlled machines or CNC machining. 

Whether you’re in the market looking for a CNC machine for sale, a CNC router for sale or just interested in how you might integrate a CNC machine into your manufacturing process, this guide is a great place to start. Follow along with us here at The Equipment Hub as we dig into the types of CNC machines, advantages and disadvantages the technology brings to your manufacturing operation, and how the Equipment Hub can help you find the right piece of equipment to fit your needs.

Types of CNC Machines

CNC machines refer to a type of machine that can be programmed to create objects through subtractive manufacturing methods. This can encompass a number of different types of machines that perform this reductive process in different ways.

CNC Mills

Traditional milling machines operate on a three-axis system (X/Y/Z axes) and are coded through number and letter prompts that guide the various tools the machine can deploy across specific distances and in defined motions to effect the desired changes in the raw material in use. Tools used with milling machines can include drills, slot and face cutters, threading tips, and flatheads, bullhead, and ball head tools. There are 5-axis CNC systems, which enjoy increased flexibility and thus are able to create increasingly complex geometries.

CNC Lathes

CNC technology allows lathe machines to execute extremely complex circular cuts with high precision and speed. While the coding is similar to that of mills, lathes generally only operate on the X and Z axes.

CNC Water Jet Cutters

Using high-pressure streams of water mixed with an abrasive substance such as sand, these machines are used to cut hard materials, such as granite or metal, which cannot be cut with other heat-intensive CNC machine methods. As no heat is generated that can warp or change the intrinsic properties of raw materials, CNC water jet cutters are also extremely useful for executing intricate and complex cuts.

CNC Spark Machining

Also referred to as die sinking or electrical-discharge machining (EDM), these machines use electrical sparks to shape and mold raw material into predefined shapes. In most models, current flows between two electrodes in close proximity, with the resulting discharge used to shave off portions of the work in progress. Variations include wire EDM and sinker EDM machines.

CNC Plasma Cutters

Mostly used for metals, these Plasma Cutters use a mixture of compressed-air gas and electrical arcs to quickly produce the necessary heat for cutting raw material in pre-defined ways at speed.

Other CNC Machine Functions and Applications

CNC machines can be fitted with a variety of tools, accessories, and components in support of manufacturing jobs requiring precision cuts at various angles and levels in any raw material. Applications where CNC machines can be deployed include, but aren’t limited to: 

•     Wood routers
•     Foam, laser, and glass cutters
•     Grinders
•     Wire-bending machines

Let’s Talk About the Advantages of Automation and CNC Machining

Using uploaded computer-aided design (CAD) models, experts translate the designs into CAD files that act as design templates and provide the foundation for the instruction set that will guide a CNC machine through the steps of carving out the target object from available raw materials.  In this process, the machine translates design parameters from these files into instructions on where to cut or grind, where to drill, how many layers to remove, and other methods by which to extract the intended object from various metals or plastics. These instructions can be used as a foundation for extremely complex repeatable programs, allowing for highly accurate reproduction in large quantities.

While historically arguments have been made that this process requires long lead times in order to execute effectively, advances in technology and cloud-distribution of resources, data, and source files allow for faster programming, more efficient sourcing of materials, and overall less interruptions in the entire process by automating the upload of CAD files and allowing single control units to control multiple CNC machines, providing the ability to scale up operations quickly and efficiently.

Because CNC machining is a reductionary manufacturing method used to create components from single pieces of raw material, the CNC manufacturing process results in fully-isotropic physical properties through the final product. This means that there are little to no variations in the physical characteristics or properties of the end-product as no foreign material is introduced into the process to change the composition of the raw material – if you start with steel, you end with steel, not a mixture of metals and ingredients.

Limitations of CNC Machining

While the advent of 5-axis CNC machines has increased the complexity of the geometric shapes that can be created, there are still shapes that are either extremely cost-prohibitive or that cannot physically be created by CNC machines. CNC machines also struggle with objects that have thin walls between sections or other intricate features, as the pressure and vibration of the manufacturing process could break or shatter such surfaces. 

While the processes are automated, much of the programming that controls CNC machines, executed in a language referred to as G-code, is still composed by people. With human error in the mix, faulty programming can lead to CNC machines experiencing a crash. In the event of a crash, poor CNC programming causes the path of the CNC machine’s tool to collide with stabilizing equipment or with the raw material at an incorrect angle. Either of these events can break the tool in use and could damage the machine in general. While some systems include sensors to keep this from happening, they are not 100% effective.

Trust The Equipment Hub for All of Your CNC Machining Needs

As automation becomes a dominant force in the manufacturing industry, CNC machines and other automated solutions are rapidly becoming more commonplace. If you’re looking for a CNC machine for sale, or you are looking for a great deal on a CNC router for sale to add to your production line, The Equipment Hub’s marketplace should be your first stop. After checking our lineup of available equipment, if you still can’t find what you need, call our team of experts, who can help you track down the right CNC machine for the job you have in mind.