3D Printing vs. CNC Machining: Advantages and Disadvantages

When 3D printing began to become more of a mainstream technology, many people crowed about how it would replace traditional manufacturing techniques, making injection molding and CNC machining things of the past. That hasn’t happened, and it’s highly unlikely that it’s going to happen. 3D printing is a wonderful technology on its own, but it has its limitations, and the same can be said for those other manufacturing methods. That’s why it’s better to think of all of them as complementary technologies, working individually and together to enhance the manufacturing ecosystem in their own ways.

On the surface, CNC machining and 3D printing look like complete opposites: one subtracts material, while the other adds it. Opposites attract, however, and CNC machining and 3D printing actually work extremely well together, which is why there is an increasing number of hybrid 3D printer/CNC machines on the market. 3D printers can print parts with finer detail and more complex geometry than CNC machines, and CNC mills can handle the post-processing required by most 3D printers, refining and cleaning up the final part.

If you’re looking to go with only one technology, though, how do you decide which is better suited to your needs? As stated above, 3D printers tend to be better in terms of fine detail, while CNC machines are more commonly used for large structural components – although there has been a growing number of large-scale 3D printers capable of handling structural components recently.

3D printers, overall, produce weaker parts than CNC machines – CNC milling cuts a part out of an already solid block of material, while 3D printing produces layers of material with a molecular bond that isn’t as strong. Metal 3D printing is plagued by issues like porosity, which many researchers are attempting to solve. CNC machining is also faster than most 3D printers, although 3D printers are getting faster and faster as the technology advances.

3D printing does have a wider range of potential applications, however. Just look at the medical field, for example. While CNC machining is still the preferred method in the industry because it more reliably produces the kind of durability and precision needed for medical devices, you can’t CNC mill human tissue, or machine tiny, complex pills and tablets containing life-saving medication.

The aerospace industry has been incorporating 3D printing more into its manufacturing processes lately, thanks to the technology’s ability to create extremely complex parts. Aerospace is a perfect example of an industry in which 3D printing and CNC machining can nicely complement each other – CNC machining’s capability for strength and size alongside 3D printing’s geometric flexibility make the two methods well-suited to working alongside each other to make engine parts and structural components.

Chinese company 3ERP understands the value of both 3D printing and CNC machining, and offers both technologies among its numerous other services. In terms of CNC machining, 3ERP provides a wide range of options: milling, turning, EDM (electrical discharge manufacturing), wire EDM, and surface grinding. It has 3-, 4- and 5-axis CNC machining centers, and can manufacture metal or plastic parts in a matter of days. On average, the company returns quotes within 24 hours, ships parts within seven days, and has a 99% on time delivery and quality rate.

3ERP 3D prints in plastic and metal, as well, and can produce anywhere from one to more than 50 parts. According to 3ERP, customers can save up to 50% in costs by going with its 3D printing services.

Regardless of whether you decide to go with CNC machining or 3D printing for your parts, it’s important to remember the benefits of both technologies, and how they can work together and by themselves to produce quality components.

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