What is the difference between 3D printing and CNC machining?

What is the difference between 3D printing and CNC machining

Prototype quotation needs to select the appropriate processing method according to the characteristics of parts to complete the prototype faster and better. At present, the main prototype processing is CNC machining, 3D printing, laminating, rapid molding, and so on. There is a big difference between 3D printing and CNC processing, mainly in material selection and use technology, which will affect the effect of the final product. Today we’re going to talk about two main differences between 3d printing and CNC machining.

3D printing and CNC machining use different materials

  • 3D printing :3D printing materials mainly include liquid resin (SLA), nylon powder (SLS), metal powder (SLM), gypsum powder (full-color printing), sandstone powder (full-color printing), wire (DFM), sheet (LOM), and so on. Among the many materials, most of the industrial 3D printing market uses nylon powder, liquid resin and metal powder.
  • CNC machining :The materials used in CNC machining are all pieces of plates, that is, plate-like materials. By measuring the length, width, height, and consumption of parts, the corresponding size of the plate is cut for processing. The choice of CNC machining materials is more than 3D printing, general hardware, and plastic plates can be CNC machined, and the density of the CNC parts is better than 3D printing.

3D printing and CNC machining

3D printing and CNC machining can cause differences in parts

As mentioned above, 3D printing and the CNC machining use different molding technologies. The principle of 3D printing is to cut the model into N layers /N multi-points, and then pile them up in order, like building blocks. Therefore, 3D printing is often the only choice for processing more complex hollow parts. Although CNC can also produce such parts, the efficiency will be much lower.

CNC machining is material reduction manufacturing, through the high-speed operation of various tools, according to the programming knife path to cut out the required parts. Therefore, CNC machining can only process a certain degree of radian rounded corners, but can not directly process the inner right Angle, to achieve through wire cutting/sparking and other processes. There is no problem with the outside right Angle for CNC machining. Therefore, 3D printing can be considered for parts with inner right angles.

If the surface area of the parts is large, it is also recommended to choose 3D printing. CNC machining of the surface is time-consuming, and if the programming and machine operator are not experienced enough. It is easy to generate obvious lines on the parts.


It is because there are so many differences between 3D printing and CNC machining in terms of technology. And finished product that it is important to give more thought to which will be better for your prototype project. 3D printing and the CNC machining each have their advantages and disadvantages. Choosing the right processing technology for your prototype plays a crucial impact.

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