CNC Machining Vs. 3D Printing – What Do You Prefer?

CNC machining is not a new technology, but 3D printing is. Over the years, 3D printed objects have gained popularity among technology addicts and novices. This new technology has a lot to offer and is making its presence felt in various production environments. All this doesn’t mean that CNC machining is losing its charm. This post discusses the strengths of both technologies – CNC machining and 3D printing, and how they add value to the manufacturing facility.

5 Major Differences between CNC Machining and 3D Printing

The following differences between the two machining styles will help you understand their benefits in various manufacturing environments.

1. Additive vs. Subtractive Manufacturing: The major difference between a 3D printer and a CNC machine is their opposite processes. How?

o   A CNC machine is fed with a huge material mass, where it is subtracted to create the desired part.

o   A 3D printer follows an additive process, where a part is built by precise addition of materials in layers one above the other.

Both these processes use Computer-aided Design Software (CAD) and Computer-aided Manufacturing Software (CAM) to design a part, however, their operation differs, as mentioned above.

2. Light Materials vs. Heavy Materials: CNC machines offer flexibility and creative freedom when it comes to various types of materials. These machines can be utilized for a broad range of materials like metal alloys (steels, aluminum, and brass), superalloys (Monel, Inconel, and Hastelloy), hardwoods and softwoods, acrylics, thermoplastics, etc. These materials require a different cutting tool, whereas they use the same tool-to-machine interfaces. This offers flexibility to change the tools.

However, desktop 3D printers are currently used for a few materials, which are mostly softer in nature. These typically include resins or thermoplastics. Unlike the CNC machines, individual printers are used for particular materials. This means the printer used for thermoplastics cannot be used for resins, or vice-versa. Advanced CNC machines enable material combinations because they are equipped with well-developed heat management systems, as well as a robust servo mechanism.

3. Very Good Tolerances vs. Tight Tolerances: CNC machining is ideal for applications that require tight tolerances. The CNC routers can be used for machining very small to very large parts. The cutting tool has typical shapes, which may add a radius to internal corners, whereas external surfaces may be sharp. These edges can be easily machined to desired tolerances. However, different 3D printers offer different dimensional accuracy. Various industrial 3D printers are capable of producing parts, which have very good tolerances. The wall thickness of a 3D printed part is restricted by the size of the effector in the machine. The 3D part sizes are very small because 3D printing demands a close environmental and process control.

4. Hand Finishing vs. Quality Finishing: Today, CNC routers are equipped with capabilities, which make secondary finishing easy. However, 3D printers are becoming a preferred choice in limited markets using custom products. The 3D printed products require hand finishing after production, which makes them a choice with typical industries. However, CNC machining is ideal for volume production that demands quality finishing.

By now you might have understood that both processes have various positives. The choice of the right process will depend on your requirement. If you require highly detailed and accurately designed products that score on quality as well, it is better to opt for an experienced CNC machining services provider. BDE, Inc. is one of the leading CNC machining service providers in the US.