3D Printing VS CNC Machining

3D Printing VS CNC Machining

Table of content

CNC (computer numerical control technology) and 3d printing are two leading manufacturing technologies for rapid prototyping and small batch production, but they use completely different production technologies to achieve their goals. CNC machining services supplier uses subtraction to eliminate unnecessary parts from a piece of material, while 3D printing uses addition to make products layer by layer on a blank area.


Both manufacturing methods have advantages and disadvantages, and it is difficult to say which one to use in your own projects or when to use. Please note that in mass production, for example, when more than 200 parts are manufactured, other manufacturing techniques such as injection molding are more suitable and more efficient. We have prepared a detailed comparison between CNC machining supplier and 3D printing. These details can be used to compare the two methods and decide which one to use.



Ⅰ. Which is better, CNC or 3D printing?


  1. Scope of application

Generally, CNC equipment is used to manufacture durable, precise and heat-resistant parts. CNC equipment from a CNC machining services supplier can be used in almost all industries, from small workshops to large-scale production plants. The application range of this technology is very broad, including jewelry, metal molds, castings, etc.

The boundary of the application scope of 3D printing is human imagination. It is widely used in mechanical engineering, jewelry, aerospace, medical fields, and even in food printing, bioprinting and construction fields.


  1. A variety of materials

CNC can use a variety of materials, such as metal alloys, plastics, and jewelry waxes. In addition, CNC is the main production tool for wood processing, and can quickly and accurately use other materials in CNC machining service in China. One of the main advantages of CNC manufacturing is that it can be used for almost all solid materials.

Most of the materials that can be used for CNC can be used for 3D printing, including a variety of plastics and alloys that are not easy to process. However, 3D printers that can process metals are very expensive.


  1. Operating cost

The CNC equipment consumables and materials of the CNC machining supplier are cheaper than those of 3D printer. However, CNC requires well-trained experts to pre-program process parameters and tool paths. This adds extra time and money to the cost of the finished product. This is why, although the manufacturing speed is relatively fast, in some cases, 3D printing is preferable.

The entry cost of 3D printing is lower and it is faster than other technologies. However, consumables and materials are much cheaper than those in CNC. In short, additive manufacturing is more advantageous in terms of unique items with a limited volume, but in terms of manufacturing more than 20 items, CNC or other technologies are more recommended.


  1. Multiple tools

Multiple tools can be used on the same device to expand the opportunities and CNC general technology can be adopted. Some equipment can automatically change the tool according to the current task, so there is no delay in the manufacturing process.

The number of tools that can be used in 3D printing is limited. Sometimes this is indeed a problem, but generally when using 3D printing, there is no need to use other technologies. The diversity of 3D printing equipment is amazing, and there is nothing that additive production cannot manufacture.



Ⅱ. CNC and 3D printing: What is the best way to manufacture parts?


The development of more powerful 3D printing materials encourages manufacturers from all walks of life to explore the comparison between CNC and 3D printing, and find ways to 3D print functional parts that were previously made by CNC machining service in China. The 3D printing process can save manufacturers a lot of time and money while still achieving the quality required for industrial-grade production.


Manufacturers who use 3D printing software can make prototype and produce parts in one day at a fraction of the cost of traditional CNC machining. However, there are still several key areas where CNC may still be the right choice.


(1) Feature size

Both the CNC of CNC machining services suppliers and 3D printing technology are limited by the size of the tool; in the case of CNC, the tool diameter determines the smallest negative feature that can be created. However, in the case of 3D printing, the nozzle diameter determines the smallest positive feature that can be produced. The nozzle diameter of extrusion-based 3D printers is usually between 0.25 mm and 0.8 mm. The minimum feature size of these machines is 4 times, resulting in a minimum feature size of between 1.0 mm and 3.2 mm.

For more detailed information on the minimum feature size of continuous fiber reinforcement, we have created a guide to the minimum feature size of fibers.

Surface treatment: With the right tools, CNC machines can produce smoother surfaces than 3D printers. 3D printers can produce suitable and finished parts, but for parts that require excellent smoothness to match other precision parts, CNC machining may be preferable.


(2) Tolerance

Some of the best composite 3D printers can control dimensional tolerances to ± 0.005 and usually have a smooth surface for press fitting. Close tolerance features of 3D printed parts can be post-processed. However, depending on the other characteristics of the part, it may be easier for CNC machining service in China to process the whole part. Your results may vary depending on the machine, material, and geometry of parts.


(3) Loading

Non-structural parts are usually simple targets for traditional 3D printing. Structural components that need to withstand heavy physical loads can be produced using continuous fiber reinforced materials or CNC processing. Although continuous fiber reinforced materials can significantly increase the strength of other 3D printed parts, composite parts are stronger on both axes (X, Y) than on the Z axis, and do not exhibit isotropic properties like metal parts.


In the debate between CNC and 3D printing, which one do you prefer?