How Does CNC Machining Work?

How Does CNC Machining Work?

In recent decades, CNC machining has completely transformed the world of engineering, becoming one of the most popular methods of digital manufacturing today. Read on to find out what CNC machining involves, the different kinds of CNC services available and which might be the best fit for your rapid prototype or production needs.

March 24, 2021

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As CNC machining is renowned for being one of the most high-tech manufacturing methods in the business, you might be surprised to hear that the first steps towards modern-day CNC machining were taken way back in the 1950s. This was when manufacturers at MIT found that they could reduce the time spent on manufacturing parts from 8 hours to just 15 minutes by allowing computers to take the lead on rapid prototyping and production. Now that’s what we’d call a life-changing discovery!

Since then, CNC machining has continued to evolve, and to completely transform the world of engineering. Today, it’s one of the most popular methods of digital manufacturing across almost every technical industry.

At Geomiq, we’re proud to be partnered with 180+ highly vetted CNC manufacturers, specialising in both CNC milling and CNC turning, who have a proven track record of making high-quality mechanical parts for customers all over the globe.

As experts in the field who are passionate about all things CNC, we’re excited to help you understand today what CNC machining is, how it works, the many benefits of CNC machining and which industries it can help the most.

What is CNC machining?

Computer numerical control (CNC) machining is a form of subtractive manufacturing, meaning that material gets removed (rather than added) during the production process. This means CNC machining starts with a block of material (called a blank), and uses fast-moving cutters to quickly carve away material and create the finished part.

This essentially makes it the opposite of additive manufacturing (e.g. 3D printing), where three dimensional objects are created layer-by-layer from materials loaded into 3D printing machines.

Crucially, CNC machining is also a metal fabrication method where written code controls the CNC machinery in the manufacturing process. Let’s take a closer look at what this means:

How do CNC machines work?

As we just touched on, CNC machines are run by a digitalised computer that automates, monitors, and controls the movement of an industrial machine. In large industrial plants, the computer is usually installed in the machines, but for hobbyists’ machines, the computer is generally attached externally.

The exact movements that this code controls depends on the type of CNC machine that is being used. Let’s take a look at some of the most common CNC machines in use today, and how they work:

Types of CNC Machines

#1 CNC milling machines

CNC milling is one of the most common types of CNC machining, known for its great accuracy and tolerances. CNC machines feature built-in tools for drilling and cutting, and after materials are placed inside them, the computer will guide the drilling and cutting tools to work their magic.

At Geomiq, we’re proud to offer both 3 axis and 5 axis high-precision CNC milling capabilities. 5 axis CNC milling is generally suited to more complex geometries and is typically done in a single operation, while 3 axis CNC milling is often the more suitable choice for creating more simple parts.

#2 CNC lathe machines

CNC turning is essentially the opposite to CNC milling, as instead of the cutting tools moving to cut material away, the material itself is rotated as it is cut. CNC lathe machines feature a lathe in the center that manipulates and moves the material into the position as programmed on the computer. This is another of our talented partners’ specialties!

#3 CNC plasma-cutting machines

Like CNC milling machines, CNC plasma-cutting machines are also used to cut materials. However, they differ from their milling counterparts as they performing this operation using a high-powered plasma torch, which can achieve temperatures up to 50,000 degrees Fahrenheit, and are strong enough to cut through rough materials like metal!

#4 CNC laser-cutting machines

Not to be confused with plasma-cutting CNC machines, laser-cutting CNC machines are also designed to cut through tough materials, but they use a laser to perform this task (rather than a plasma torch). These lasers tend to have a higher level of cutting accuracy, but aren’t quite as strong as plasma torches.

#5 CNC electric discharge machines

A CNC electric discharge CNC machine, also known as a spark CNC machine, is a special type of CNC machine that uses electrical sparks to manipulate materials into the desired shape. Materials are placed between a top and bottom electrode, after which the computer dictates how much electrical discharge the electrodes produce – and how the part is reshaped.

5 benefits of CNC machining

Because CNC machines allow manufacturers to automate many manufacturing processes that would otherwise have to be performed manually, they increase productivity, accuracy, and help reduce the risk of human error.

Here are 5 key ways they have transformed the world of engineering:

#1 CNC machining is great for creating large quantities of parts

It’s far cheaper to create large quantities of prototypes and parts through CNC machining than it is to go with 3D printing, so if you’re looking to create larger quantities of mechanical parts (from the higher double digits into the 100s) CNC is likely to be the most cost-effective choice.

#2 CNC machines can work with many materials

While 3D printing is largely focussed on plastics, CNC machines are relatively indifferent to what they are cutting – so long as the material is rigid enough not to deform or melt under the pressure of the cutting action. At Geomiq, we offer over 60 production grade materials for CNC machining, and take great care to ensure the right material is used for every part. Most commonly, metals used include aluminium, stainless steel, magnesium alloy, zinc alloy, titanium and brass.

#3 CNC machines can create parts quickly

It probably won’t come as a surprise to you that machines work quicker than humans do! When you order your CNC machined parts through Geomiq, we’ll not only get you a quote within one business day – you’ll receive the finished products in as little as 5 days!

#4 CNC machines are highly accurate

To give you an idea of how accurate they are, at Geomiq, our standard CNC tolerance is +/- 0.127mm, and when you use our tolerance configurator, you can expect precision machining down to +/- 0.005mm.

#5 CNC machining allows for a variety of post-processing and finishing options

For example, at Geomiq, we offer high-quality finishing processes for most CNC machined parts; from anodising, polishing and plating, to heat treatment, powder coating and more.

Which industries use CNC machining?

At Geomiq, we are proud to offer CNC machining capabilities for an extremely wide range of industries. From aerospace and energy products to electronics and automotive goods, we’ve seen firsthand how useful beautifully CNC machined parts can be used for almost any and every industry.

In particular, we’ve seen CNC machining being very important to engineers in sectors where high accuracy is absolutely necessary, such as the aerospace industry, robotics industry and the medical industry.

However, it is also used in a wide range of other industries, such as:

  • Electrical
  • Defence
  • Mining
  • Industrial machinery
  • Food & beverage
  • Clothing
  • Automotive
  • Agriculture

Essentially, there are no limits to what you can do with CNC machining! If you need a part made (either for prototype or production) accurately or in large quantities, CNC might just be the right choice for you.

Let’s get CNC machining

Ultimately, CNC machining is a great option for engineers in any industry who are looking to order high volumes of accurate mechanical parts for rapid prototyping or production.

To find out which method is right for you and your project’s unique requirements, we’d advise you to speak with a trustworthy digital manufacturing platform or provider and ask for their advice.

When it comes to a manufacturing method as reliable, precise and diversely applicable as CNC machining, there is a world of possibilities at your fingertips. Simply choose the right supplier – and the right digital manufacturing platform – when ordering your CNC machined parts, and you really can’t go wrong.

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Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of Geomiq. Examples of analysis performed within this article are only examples. They should not be utilized in real-world analytic products as they are based only on very limited and dated open source information. Assumptions made within the analysis are not reflective of the position of any Geomiq Employee.