3D printers are advanced machines used to produce a physical object from a digital design.
A CNC machine removes material from stock to make a product.
But is a 3D printer a CNC machine? What are the differences between the two?
This article talks about 3D printers and CNC machines, how they are related, their working, applications, and much more.
MellowPine is reader-supported. When you buy through links on my site, I may earn an affiliate commission at no extra cost to you.
Is a 3D printer a CNC machine?
A 3D printer is a CNC machine that does additive manufacturing. It works similar to other Computer Numerically Controlled machines like CNC mills. However, instead of removing material, a computer system guides the movement of the nozzle that deposits layers of material to attain the desired shape.
Some of the popular CNC machines include CNC routers, mills, lathes/turning centers, laser cutters, press brakes, 3D printers, etc.
All these machines have similar working principles but use different manufacturing techniques.
3D Printers and CNC Machines – What are they?
What is a CNC Machine?
A CNC machine, also called a computer numerical control or machining center, is a manufacturing machine that automates subtractive, additive, or formative manufacturing processes.
Here the machine transmission is programmed by a machinist, and the program is fed to the computer-controlled machine.
The CNC controller onboard the machine analyzes the program data and implements it by accurately moving the machine parts, tools, and workpieces.
What is a 3D Printer?
A 3D printer can print three-dimensional parts and objects. These objects are created by laying down successive layers of material on top of the other.
Technically, a 3D printer is a type of CNC machine as it consists of a computer that automates the printing process.
Unlike other CNC machines that consist of a cutting tool, a 3D printer consists of a printing nozzle that delivers the building material in the desired pattern.
3D Printers vs CNC Machines – What’s the difference?
| Parameter | 3D Printing | CNC Machining |
|---|---|---|
| Manufacturing Technique | Additive manufacturing | Subtractive manufacturing |
| Material Capability | Comparatively low | Very High |
| Applications | Prototyping and small-scale manufacturing | Low, medium, and large-scale manufacturing |
| Surface Finish | Comparatively low | Comparatively High |
| Operating Speed | Comparatively low | Comparatively High |
Difference between 3D printing and CNC machining
3D Printing vs CNC Machining
In 3D printing, layers of material are added on top of one another to produce the desired three-dimensional shape.
CNC machining is a process wherein materials like metal, wood, plastic, etc., are cut or shaped using a computer-controlled machine tool.
So the biggest difference between 3D printing and CNC machining is that CNC machines use subtractive manufacturing techniques to make different parts while 3D printers use additive manufacturing.
How Do They Work?
A 3D printer can create three-dimensional parts from a digital file. It builds an object by depositing material in successive layers based on computer instructions.
Whereas CNC machines like mills use subtractive manufacturing to remove material from the workpiece from which the object is being created.
Though these machines work differently, they have a similar workflow.
First, you need to make the design and then convert the design into code using CAM software.
A CAM software gives out the part program in files like G-code. Then you have to use a CNC control software to send the program to the machine.
Pros and Cons of Working with 3D Printers and CNC Machines
3D printers and CNC machines are both computer-controlled fabrication tools. They can make physical objects or parts from digital designs.
While most other CNC machines cut away material to create shapes, 3D printers lay down successive layers of material to make desired objects.
CNC machines, like mills, lathes, etc., can remove materials and carve out a shape much faster than a 3D printer depositing and building the same.
For example, when I tried making a 19 cm tall vase on the 3D printer Snapmaker 2.0, it took me about 3 hours and 15 minutes. But if it was made using a machining center, It could take about 10-30 minutes.
Unfortunately, 3D printers and other CNC machines are expensive and can cost anywhere from $2000 and above, depending on the model you buy.
Applications
Luckily, over the last few years, the technology behind these machines has developed and become more accessible.
Due to these advancements, their prices are going down, and the accuracy, reliability, and build volumes have gone up.
Now many companies are using 3D printing for making lightweight aerospace parts, custom medical implants, construction, and other complex-looking parts that otherwise are hard to make.
Unfortunately, the parts made using 3D printers lack the level of tolerance other CNC machines offer.
CNC machines like mills, routers, lathes, grinders, etc., are widely used as these machines allow you to make parts out of most materials with high accuracy and repeatability in less time.
Hence they are largely used to manufacture similar parts in large quantities. To name a few, they are employed in manufacturing applications of automobiles, aerospace, defense, and more.
Final Thoughts
Applications employing 3D printing are growing every day, and many now consider 3D printers as separate machines from common types of CNC machines.
In addition, 3D printers have their own line of dedicated software, but they essentially work similarly to other CNC machines.
Both are computer controlled and work using the principles of numerical control technology.
Frequently Asked Questions
What materials can I 3D print?
You can 3D print materials like ABS, PLA, nylon, stainless steel, gold, silver, titanium, ceramics, glass, carbon fiber, graphite, wood composites, resins, and more.
What are some of the popular CNC Machines?
Some of the popular CNC machines among machinists are CNC mills, routers, lathes, laser cutters, plasma cutters, waterjets, Electrical Discharge Machines (EDMs), and grinders.
Is CNC or 3D printing cheaper?
The cost of CNC is higher than 3D printing because it requires expensive machinery, but it is usually faster than 3D printing. Due to the advancements in technology, 3D printing is now cheaper, but they are slower than CNC, and the quality of their finished products is lower.
