PCBWay Customization Service: With customers providing 3D and 2D files, we utilize various manufacturing methods such as CNC machining, 3D printing, sheet metal processing, and more to produce metal or plastic components according to the customers' specifications while ensuring quality and on-time delivery.
The most straightforward answer: 3D printing is an additive manufacturing technique, while CNC machining is a subtractive manufacturing technique.
Next, let's compare 3D printing and CNC machining based on the following four points:
Differences in Materials
The main materials used in 3D printing include liquid resin (SLA), nylon powder (SLS), metal powder (SLM), gypsum powder (full-color printing), sandstone powder (full-color printing), filament (FDM), sheet material (LOM), and others. Liquid resin, nylon powder, and metal powder dominate the majority of the industrial 3D printing market.
In contrast, CNC machining exclusively uses sheet materials, which are flat, plate-like materials. First, measure the dimensions of the component, including length, width, height, and allowances for machining, and then proceed to cut the corresponding-sized sheet material for processing.
CNC machining offers a wider range of material choices than 3D printing, with the ability to work with various metal and plastic sheet materials. Additionally, CNC-machined components typically have a higher density compared to 3D printing.
Differences in Components Due to Distinct Forming Principles
As mentioned earlier, 3D printing is an additive manufacturing process, based on the principle of slicing a model into N layers or N points and then sequentially building it up layer by layer or point by point, much like assembling building blocks. Therefore, 3D printing is effective at producing complex parts with intricate structures, such as hollow components, which can be challenging to achieve with CNC machining.
CNC machining is a subtractive manufacturing process that uses various high-speed cutting tools to fabricate the required components following programmed tool paths. Therefore, CNC machining can only produce rounded edges with a certain radius and cannot directly create internal right angles——this typically requires processes such as wire cutting or EDM. External right angles can be machined using CNC without any issues.
Components with internal right angles can be considered for 3D printing manufacturing.
Additionally, when it comes to curved surfaces, if a component has a relatively large curved surface area, it is also advisable to consider 3D printing. CNC machining of large curved surfaces can be time-consuming and, with insufficient programming or less experienced machinists, it can easily result in noticeable patterns on the components.
3D printing involves stacking layers of cake-like powder to create a single cake, while CNC machining is akin to slicing a large cake into individual pieces, which might make it easier to understand.
Differences in Operating Software
Most 3D printing slicing software is straightforward to operate. Even novices, with professional guidance, can become proficient in using slicing software within a day or two. This simplicity is due to the optimization of slicing software, with most supports being automatically generated, which is also why 3D printing has become accessible to individual users.
CNC programming software, on the other hand, is much more complex and typically requires the expertise of professionals. Those with no prior knowledge often need around six months of learning. Additionally, the operation of CNC machines necessitates the presence of a skilled CNC machinist. Commonly used software includes UG, Solidworks, AUTOCAD, FreeCAD, among others. Learning to use these software programs can be quite challenging.
Differences in Post-Processing
In the case of 3D-printed components, post-processing options are relatively limited and typically involve procedures such as sanding, oil coating, deburring, and dyeing.
In contrast, CNC-machined components offer a wide array of post-processing choices, which extend beyond sanding, oil coating, and deburring to encompass techniques like electroplating, screen printing, pad printing, metal oxidation, laser engraving, sandblasting, and more.
