When quoting for the prototype project, we need to select the appropriate processing method according to the characteristics of the parts to complete the prototype project faster and better. At present, hand plate processing mainly includes CNC machining, 3D printing, laminating, rapid tooling and so on. Today, let's talk about the difference between CNC machining and 3D printing.
First of all, 3D printing is an additive technology, and CNC machining is a material reduction technology, so they are very different in terms of materials.
1. Differences in materials
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), etc. Liquid resin, nylon powder and metal powder occupy most of the market of industrial 3D printing.
All the materials used for CNC machining are plate-like materials. By measuring the length, width, height and wear of the parts, the corresponding size of plates are cut for processing. There are more choices of CNC machining materials than 3D printing. General hardware and plastic plates can be CNC machined, and the density of formed parts is better than 3D printing.
2. Part difference due to molding principle
As mentioned above, 3D printing is a kind of additive manufacturing. Its principle is to cut the model into N layers / N points, and then stack it 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 process hollow parts.
CNC machining is a kind of reduced material manufacturing. Through various cutters running at high speed, the required parts are cut according to the programmed cutter path. Therefore, CNC machining can only process rounded corners with certain radians, but can not directly process inner right angles, which should be realized by wire cutting / sparking and other processes. CNC machining of outer right angles is no problem. Therefore, 3D printing can be considered for parts with inner right angles.
There is also the surface. If the surface area of the part is large, it is also recommended to choose 3D printing. CNC machining is very time-consuming. Moreover, if the programming and operator are not experienced enough, it is easy to leave obvious lines on the part.
3. Differences in operating software
Most slicing software for 3D printing is simple to operate, and even laymen can skillfully operate slicing software in a day or two under professional guidance. Because the slicing software is currently optimized to be very simple, the support can be automatically generated, 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 generally need to learn it for about half a year. In addition, a CNC operator is needed to operate the CNC machine.
Because the programming is very complex, a part can have many CNC processing schemes, while 3D printing will only have a small impact on the processing time and consumables because of the placement position, which is relatively objective.
4. Difference in post-processing
There are not many options for post-processing of 3D printed parts, generally grinding, oil spraying, deburring, dyeing and so on.
In addition to grinding, oil spraying, deburring, electroplating, screen printing, pad printing, metal oxidation, radium engraving, sandblasting and so on, there are various options for post-processing of CNC machined parts.
There is a succession of hearsay and specialisation in art. CNC machining and 3D printing have their own advantages and disadvantages. Choosing the right processing technology plays a vital role in your prototype project. Choose Qile, and our engineers will analyze and suggest your project.