What is the difference between 3D printing and CNC?

Date：2020-04-13 13:36　Popularity：

When quoting a Shouban project, it is necessary to select an appropriate processing method according to the characteristics of the parts to complete the Shouban project faster and better. At present, the main board processing includes CNC machining, 3D printing, laminating, rapid mold and so on. Today we talk about the difference between CNC machining and 3D printing.

First of all, 3D printing is an additive technology, and CNC machining is a subtractive technology, so they are very different in terms of materials.

1. Differences in materials

The materials 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 (DFM), and sheet (LOM) and many more. Liquid resin, nylon powder and metal powder occupy most of the market for industrial 3D printing.

The materials used for CNC machining are all plates one by one, that is, plate-shaped materials. By measuring the length, width and height of the parts + wear, and then cutting the corresponding size of the plate 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 molded parts is better than 3D printing.

2. Differences in parts due to molding principles

As we mentioned earlier, 3D printing is an additive manufacturing. Its principle is to cut the model into N layers / N multi-points, and then layer by layer / point by point in order, just like building blocks. same. Therefore, 3D printing can effectively produce complex structural parts, such as hollow parts, and CNC is difficult to process hollow parts.

CNC machining is manufactured by subtractive materials. Through various tools running at high speed, the required parts are cut according to the programmed tool path. Therefore, CNC machining can only process rounded corners with a certain degree of arc, but cannot directly process internal right angles, which must be achieved through wire cutting / sparking and other processes. CNC machining at right angles is no problem. Therefore, parts with inner right angles can be considered for 3D printing and processing.

There is also a curved surface. It is also recommended to choose 3D printing if the surface area of the part is relatively large. CNC machining of the curved surface is very time-consuming, and if the experience of programming and operator is not enough, it is easy to leave obvious lines on the parts.

3. Differences in operating software

Most of the 3D printed slicing software is easy to operate, and even lay people can master the slicing software in the next two days under professional guidance. Because the slicing software is currently optimized very simply, the support can be automatically generated, which is why 3D printing can be popularized to individual users.

CNC programming software is much more complicated and requires professionals to operate. People with zero foundation generally need to learn about half a year. In addition, a CNC operator is required to operate the CNC machine.

Because programming is very complicated, a part can have many CNC machining solutions, and 3D printing is relatively objective because of the small effect of the placement on the processing time consumables.

4. Differences in post-processing

There are not many post-processing options for 3D printed parts. Generally, they are sanding, oil injection, deburring, dyeing and so on.

And CNC machined parts post-processing options are varied, in addition to grinding, oil spraying, deburring, as well as electroplating, silk screen, pad printing, metal oxidation, laser engraving, sand blasting and so on.

Wen Dao has succession, and the art industry specializes. CNC machining and 3D printing have their own advantages and disadvantages. Choosing the right processing technology has a crucial impact on your Shouban project.