As 3D printing manufacturing continues to grow in popularity, many people ask, “Will 3D printing manufacturing replace CNC machining?” The good news is that it doesn’t have to. Both 3D printing and CNC machining have their place in manufacturing. The key is to know which is better for your project. So, what are the things you should consider? Let’s take a look.
What is the difference between 3d printing and CNC?
The key difference between 3D and CNC is that 3D is an additive process whereas CNC is a subtractive process. A 3D printing manufacturing process is building a piece layer by layer. A CNC machine is removing materials from a larger piece of material. Both use computer modeling that can be run through several iterations — even tested with Artificial Intelligence — before manufacturing. And both can use algorithms to greatly reduce the cost of waste material.
Advantages of 3D Printing Manufacturing over CNC Manufacturing
3D printing manufacturing has several advantages over CNC machining when it comes to plastics. The first big advantage is prototyping. With rapid prototyping becoming the norm in both startups and existing manufacturers, the ability to quickly print out a prototype –without writing CNC programs and designing fixtures, is a huge advantage in the design process. The second advantage is waste. At the end of the job, most of the left over material in a 3D print job is reusable — you’re not left with a pile of waste. Finally, 3D printing manufacturing can produce fully assembled parts, and parts within parts. That’s not possible with a CNC machine.
Now, CNC machining also has its advantages. For example, the first is speed for metal parts. Today, even as 3D technology continues to make significant improvements in speed, a CNC job metal part can be produced more quickly. However, if you’re CNC milling in production, speed may no longer be an advantage. Second is, as we mentioned, materials. CNCs today can cut out parts from wood, metal, and plastics. Finally, CNCs are better for producing large parts, outside the limits of most additive 3D printers.
3D versus CNC: Cost
For lower run jobs, 3D printing manufacturing is going to be lower cost than CNC machining due to programming and setup needed in CNC jobs. Lower run jobs include part numbers in the low 100s or below. Above that, CNC starts to become more cost competitive. The consideration to make in that case is that with higher runs comes more waste material with CNC manufacturing. At the highest runs, injection molding can become the most cost effective solution.
Conclusion: Will 3D Replace CNC?
The quick answer is no. CNC is not likely to get totally replaced by 3D manufacturing. But we don’t really think that’s the central discussion. The key is to find the RIGHT manufacturing process for your project, and that might include 3D, CNC, or even injection molding. While 3D holds some distinct advantages such as prototyping, reduced waste and assemblies, CNC can hold its own with certain materials, speed, and cost on larger jobs.