CNC Machining VS 3D printing: which is the best technology for prototyping?

3D printing is a kind of additive technology. CNC machining is a kind of material reduction technology (subtractive technology). Next, we will talk about the differences between them from four levels, or what are the advantages and disadvantages?

Both CNC machining and 3D printing technology are computer controlled to solve product problems, and products can be made from specific materials. They are machines that are at the forefront of safe and efficient construction techniques.

When mechanics and engineers want to build parts or custom products, they can use either machine to do their job. As long as the machine has design features, you don't have to worry about making mistakes because the machine is automated. It can reduce the risk of errors. .

Some of them are the same. Most CNC machines can use STL or OBJ files, and 3D printers also receive these files. They are not another alternative because they are both aspects of manufacturing. They meet different needs and handle different materials and markets.

1 Manufacturing process difference

CNC machining is done by rotating the tool to cut the material. It is a method of subtraction. Because it cuts off the material

3D printing is done by dissolving materials and building them into finished products. It is the process of addition.

These two processing methods are different in terms of durability and accuracy of the product.

2 Material difference

CNC machining is suitable for a variety of materials. The most common are Aluminum, Copper, Brass, Steel, Stainless steel, Titanium, Zinc Alloy, ABS, ASA, Acrylic, Nylon, HDPE,LDPE, PEEK, PP, PE, wood and so on.

The materials of 3d printers are mainly thermoplastics and resins. And the equipment will be different depending on the material.Compared with nc machining, the parts produced by 3d printers are relatively weak in firmness and durability.

3 Precision

There is no doubt that CNC machining is much more accurate than 3D printing. CNC machined products do not affect accuracy due to high temperatures. But the products produced by 3D printing technology are easily deformed. Most of the time, 3D printing technology is suitable for products with low precision and complex design.

The following table serves as a comparison reference

Technology	Tolerance
CNC machining	±0.01mm
3D printing - SLS	±0.3mm
3D printing - SLM	±0.1mm

4 Production and processing speed

After the first set of CNC machining equipment, the products can be automatically produced 24 hours a day. CNC machining takes one hour of product, and a 3D printer will cost two hours or more. The products produced by 3D printing also need cleaning, polishing and other processes. CNC machining products do not require such operations.

5 Cost 

The amount of cost is determined by the complexity and quantity of the products. If your design is very simple and quantity 100pcs, I recommend you use 3-axis CNC machining. If your sample is very complicated and requires 5-axis CNC machining, I recommend using 3D machining to achieve your product effect. . It can save you most of the cost.

6 Workflow

CNC machining is a highly operative machining method. The operator must consider the choice of tool, the choice of cutting path, and the coordinate axis positioning of the part. Operators need to be experienced and attentive. One step is wrong, and the parts may be scrapped.

Operators of 3D printer need to enter content into the machine. After that the machine will run automatically. The most time consuming is that the 3D printed product must be processed later. Subsequent processing is very time consuming and laborious.

What they have in common is that they require professional personnel to operate. Once a misoperation occurs, all efforts will be wasted.

7 Noise

There is no doubt that the cutting sound of CNC machining is deafening. Whether it is metal, plastic or wood, its sound is very large.

The sound of 3D printing technology is very light, and it has no soundproof cover, its sound may be softer than the sound we knock on the keyboard.

There is such a saying in the industry: the sound of the 3D printer makes my child fall asleep.

8 Waste

Obviously, 3D printing technology produces almost no waste. However, the process of CNC machining of it produces a lot of waste, and most of the waste is not recycled. If your product materials are very expensive, you can consider 3D printing technology.