Computer numerical control (CNC) machining and 3D printing are the two most commonly used processes in manufacturing today. Both of these technologies can save you a lot of money and a lot of time, while allowing you to produce high-quality parts.

However, 3D printing and CNC machining have different functions. This means that for a specific engineering design scenario, one may be a better choice than the other.

If you are not sure which process is the best choice for manufacturing a product, then you have come to the right place. This article will help you find the best option for your manufacturing needs. When choosing CNC machining and 3D printing as manufacturing solutions, please continue to read five considerations.

The choice of materials for 3D printing is limited because the technology is a fairly new innovation. The lack of available materials is mainly due to the limitations of the 3D printer itself. In addition, some new materials are still under development or not yet fully commercialized.

This is why 3D printing currently uses resins or thermoplastics. As far as plastics are concerned, they are an ideal material because their lower melting point makes them easy to manage, not to mention that they are cheap. The demand for this production method is growing, so it can be expected that its material selection will increase in the next few years. However, compared with other manufacturing processes, the number of suitable materials will not be so large. This makes it difficult to use 3D printers in more applications.

On the other hand, precision machining workshop Moseys Productions and other machining companies can accommodate a wider range of materials. Some materials compatible with CNC machining are metal alloys, acrylic, wood, and thermoplastics.

Certain geometric figures cannot be created by CNC machining. That's because the CNC tool touches the workpiece from the top. It cannot access all sides of the part without rotating the part-the required repositioning leads to increased processing and labor time, which can be a problem for many companies. For example, using CNC machines to create hidden features and undercuts is a challenge.

In situations where you need to create parts with complex geometries, it is best to use additive manufacturing processes such as 3D printing.

The minimum feature size is the minimum size of the workpiece feature that the processing equipment can create.

In 3D printing, you can create parts with minimum feature sizes between 0.25 mm and 0.88 mm. However, 3D printers cannot print parts larger than the print bed. You can print some larger parts, but you need to break them down into smaller parts first. Since the components are printed separately, you must assemble them later, which increases the time of the production process. 

On the other hand, the minimum feature size of CNC machine tools is between 1 and 3 mm. This is approximately four times the smallest feature size of a 3D printer. CNC processing can also produce large objects such as refrigerators.

Material compatibility, geometry and minimum feature size-these are not as important as delivery time for companies.

So which one has a better delivery time: 3D printer or CNC machine? Generally speaking, when one of your goals is fast turnaround, 3D printing is a better choice. 3D printed parts can be produced within a few days. This type of printer also eliminates the need for tool changes when creating the next version of the design or a different project, thereby further reducing delivery time.

However, when manufacturing larger batches, CNC machining may be a faster process overall. This is because unlike 3D printing, no post-processing operations are required when using CNC machines. If you are manufacturing more than 100 identical parts, this is especially true for faster delivery times in CNC machining. Once set up, the CNC machine can run continuously even without supervision. Therefore, for the same part with more than 100 units, CNC machining can be much faster than 3D printing.

Like fast delivery, cost-effective manufacturing technology is also the dream of every product designer. The cheaper choice between 3D printing and CNC machining depends largely on the batch size.

Generally speaking, 3D printing is more affordable for small-batch production or just making a prototype. On the other hand, the tool setup and programming required for CNC machining will increase the cost of small batches or individual parts. However, if you make 50 to 100 prototypes or run a larger scale, it may provide better value.

The advantages of 3D printing and CNC machining make it suitable for different applications. In other words, there is no one-size-fits-all manufacturing technology. The process that works for you depends on the product you will produce. Hope that the various factors mentioned and discussed above can help you make the right choice.

About Manufactur3D Magazine: Manufactur3D is an online magazine about 3D printing. It publishes the latest 3D printing news, insights and analysis from all over the world. Visit our 3D printing education page to read more such informative articles. Keep up to date with the latest developments in the 3D printing world, like us on Facebook or follow us on LinkedIn.