Today we will talk about the difference between CNC machining and 3D printing. 3D printing is an additive material technology, while CNC machining is a reducing material technology, so they differ greatly in terms of materials.

1, Differences in materials

The materials used for 3D printing mainly include liquid resin (SLA), nylon powder (SLS), metal powder (SLM), gypsum powder (full color printing), sandstone powder (full color printing), wire material (DFM), sheet material (LOM), and so on. Liquid resin, nylon powder, and metal powder occupy the vast majority of the industrial 3D printing market. The materials used in CNC machining are all sheet materials, which are in the shape of plates. By measuring the length, width, height, and wear of the components, corresponding sized plates are cut for processing. There are more options for CNC machining materials than 3D printing, and general hardware and plastic plates can be CNC machined, and the density of formed parts is better than 3D printing.

2, Part differences caused by forming principles

As we mentioned before, 3D printing is a type of material additive manufacturing. Its principle is to cut the model into N layers/N multiple points, and then pile them up layer by layer/point by point in order, just like building blocks. Therefore, 3D printing can effectively process and produce parts with complex structures, such as hollow parts, while CNC is difficult to achieve the processing of hollow parts. CNC machining is material reduction manufacturing, which uses various high-speed cutting tools to cut the required components according to the programmed cutting path. Therefore, CNC machining can only process rounded corners with a certain degree of curvature, and cannot directly process inner right angles. It needs to be achieved through processes such as wire cutting/sparking. There is no problem with CNC machining of outer right angles. Therefore, parts with inner right angles can be considered for 3D printing and production. Also, there is the curved surface. If the surface area of the part is large, it is recommended to choose 3D printing. CNC machining of curved surfaces is time-consuming, and if the programming and operator experience is not sufficient, it is easy to leave obvious patterns on the parts.

3, Differences in operating software

Most slicing software for 3D printing is easy to operate, and even a green hand can proficiently operate slicing software within a day or two under professional guidance. Because slicing software is currently optimized very simply and supports automatic generation, which is why 3D printing can be popularized to individual users. CNC programming software is much more complex and requires professionals to operate it. People with zero foundation usually need to learn it for about six months. Additionally, a CNC operator is required to operate the CNC machine. Due to the complexity of programming, a component can have many CNC machining schemes, while 3D printing only has a small impact on processing time and consumables due to its placement, which is relatively objective.

4, Differences in post processing

There are not many options for post-processing 3D printed components, usually including polishing, oil spraying, deburring, powder painting, and so on. The post-processing options for CNC machining components are diverse, including polishing, oil spraying, deburring, electroplating, screen printing, anodization, black oxidation, laser engraving, sandblasting, and so on.

CNC machining and 3D printing each have their own advantages and disadvantages. Choosing the appropriate processing technology plays a crucial role in your tablet project. Choose Anxin metal, and our engineers will analyze and recommend your project.