In the modern industrial era, two of the most popular cutting-edge manufacturing methodologies—3D printing and CNC machining—can be used to produce almost any product design you can think of. However, each approach has a distinct mode of operation, benefits, and capacity, making them perfect for various engineering design scenarios. In this blog, we will look at the fundamental difference between 3D printing and CNC machining, as well as reliable information about each method, manufacturable characteristics, material appropriateness, and post-processing alternatives.
3D Printing Vs CNC Machining – Key Differences
What is 3D printing?
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3D printing is also referred to as an additive manufacturing method that entails the process of layering materials to create a product. As a result of technological and materials advancements, additive manufacturing is developing dramatically. Since its invention in the 1980s as a tool for product designers to physically recreate prototypes from their computer plans, 3D printing has grown in popularity because of its speed, adaptability, and cost advantages.
What is CNC Machining?
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In the manufacturing process known as computer numerical control (CNC) machining, high-end industrial tools and machinery are moved according to pre-programmed computer software in order to produce the required final result. The CNC machining process can be used to control a range of complex machinery, from grinders and lathes to mills and CNC routers, for manufacturing any desired 3D products. When a CNC machine is turned on, the necessary cuts are programmed into the software and dictated to the appropriate equipment and machinery, which carry out the pre-defined dimensional tasks more accurately.
Factors That Differentiate 3D Printing and CNC Machining
The primary distinction between 3D printing and CNC machining is that the former is a type of additive manufacturing, while the latter is a subtractive manufacturing process. 3D printing and CNC machining aim to solve manufacturing problems at a top standard and professional rate. To help you decide when to employ each procedure based on the application, requirements, and your budget, we’ve gone into further detail below about the underlying distinctions between each.
Minimum Feature Size and Geometry
With a minimum feature size of 1 mm, the subtractive nature of CNC machining enables the production of a wide variety of complex geometries. For instance, CNC lathes are better suited for complex circular shapes, whereas CNC milling machines are perfect for angled cuts, making holes and cavities. However, creating undercuts and hidden features using CNC machines could be challenging.
On the other hand, 3D printers eliminate the geometry challenge and constraint in CNC machining in order to manufacture complicated geometries. Most 3D printers with significant volume components have minimum feature sizes varying from 0.25 mm to 0.8 mm and incur significant manufacturing expenses.
Surface Finishes
When compared to the best results 3D printers can create, CNC machining offers higher surface quality. In contrast to 3D printer output, which often necessitates additional processes to complete a task, CNC-produced parts can be sent directly to their final destination. This reduces the effectiveness of 3D printing compared to CNC. Also, for applications that require precision, 3D printers fall short. For instance, CNC milling offers mechanical accuracy of one micrometer on every axis, a degree of precision unattainable with 3D machinery.
With the proper equipment, CNC machines can create significantly smoother surfaces than those produced by 3D printers. While 3D printers can make parts with a good fit and finish, CNC machining may be preferable for pieces that must be exceptionally smooth to mate with other precision components.
Materials
A wide range of materials, including polymers and metals, can be used with both 3D printing and CNC machining. But basically, 3D printing focuses more on plastics. Since 3D printed items are typically made of unique materials, they frequently lack the durability required for usage in demanding environments like those found in vehicles, airplanes, and manufacturing equipment.
On the other hand, CNC machines that can work with heavy materials can be used to manufacture large-scale components for aircraft, engines, and other gear. For CNC parts, accuracy, reliability, and durability are requirements. Furthermore, CNC machines may work with a variety of materials, including metals, wood, plastics, and composites. Some of the materials that are frequently used for CNC machining include aluminum, brass, stainless steel, titanium, polycarbonate acrylic, polypropylene, and PEEK.
Speed
Another important distinction is the speed at which CNC machining and additive manufacturing processes operate. Since each component is produced by a series of machines in an assembly line, CNC machining is quicker when mass producing a product. In contrast, 3D printing is less suited for mass production because it uses a single 3D printer to create the entire object from beginning to end.
Furthermore, CNC machines operate really quickly. Many are able to produce hundreds, perhaps thousands, of pieces in a single shift and can easily cut through rigid material. The only disadvantage of the CNC is that it takes longer to set up than a 3D printer. It can take a lot of time for operators to load tools, fixtures, stock materials, etc. On the other hand, 3D printers take relatively minimal setup time. Starting a print typically only requires loading a file and pressing a button, supposing the printer has been calibrated and aligned.
Cost
The cost of 3D printed parts is typically lower for a number of reasons. Even the cost of the 3D printing machines is comparatively lower. They use affordable raw materials and require very little setup time. With 3D printers, there is less wear and tear, and producing parts doesn’t call for expensive tooling. For small/prototype pieces, 3D printing can be a very cost-effective method, and several schools and libraries offer 3D printing facilities for a small fee.
On the other hand, the cost of components manufactured using a CNC machine can be higher. When producing small batches of parts, CNC machines can be expensive due to the need for tooling, setup time, maintenance, and trained operators. Furthermore, a CNC machine has unmatched speed, accuracy, and quality. The cost per part can considerably decrease when producing more significant quantities, making it a very cost-effective and effective method of production.
Ease of Use
It is well known that 3D printing is more straightforward to operate than CNC machining. This is due to the fact that, after the file is ready, all that is left to do is select the part’s orientation, fill, and support, if necessary. The printer can then be left running until the piece is done without the need for a supervisor after printing has started. The amount of post-processing needed depends on the technology.
However, CNC machining requires a lot more labor than traditional milling. It takes a professional operator to decide which tools to use, how fast to rotate them, where to cut, and whether to move the material being used to make the part. Additionally, there are post-processing methods that can take extra time.
Applications
As a modern, thriving technology, 3D printing is used in many different industries due to its attractive and appealing end products. The applications cover a wide range of fields, including building materials, printing food, bioprinting, mechanical engineering, jewelry, aerospace, and healthcare.
In contrast, CNC machines are typically employed to produce strong, accurate, and heat-resistant parts. Almost every industry uses CNC machines, from small firms to massive manufacturing plants. The technology has a wide variety of uses, including jewelry, metal molding, casting, and other things.
Conclusion
In this blog, we have gone through several factors that majorly distinguish 3D printing and CNC machining. Although CNC technology and 3D printing have some capabilities in common, they also each have advantages that make them suited for particular applications. For applications that call for complex, exact products built from widely accessible materials, CNC mills are typically the best option. The qualities of 3D printers make them perfect for producing prototypes, visual demonstrations, and goods with unique designs. You can choose the suitable manufacturing process to obtain the desired final goods precisely as you wish by taking into account your business demands, client requirements, and use cases.
