For Prototype Development, 3D Printing or CNC Prototypes, Which to Choose?

When manufacturing product prototypes to support product development, three-dimensional printing and CNC prototypes (CNC) milling machines are two prototyping processes that need to be considered. How to choose between these two processes in specific applications, especially when the design and product specifications have not been finalized? Combined with specific cases, we can know the characteristics of the two processes.

I. Advantages of 3D printing process:

1. Without the use of molds, 3D printing can produce complex geometry without affecting time or cost. It allows users to quickly deliver small quantities of parts, and can flexibly and quickly adapt to design changes.

2. 3D printing supports parallel part processing flow, which can save time. Users can produce multiple parts in a single project, multiple versions of a single part, or multiple parts for different projects.

3. There is no need to use multiple settings to manufacture parts, and there is no need for operator supervision or intervention. After starting the operation, the equipment will run until the part manufacturing is completed.

II. Quality characteristics of 3D printing and CNC prototypes machining

1. Materials. The 3D printing process as a whole can handle a wide range of material categories, but each technology can only handle one type of material, covering a small number of materials in the corresponding categories. CNC prototype can process a variety of materials, each of which contains many choices, and the only limiting factor is whether the materials can be processed.

2. Material properties. After the CNC prototypes processing, the mechanical properties of the prototype are almost the same as those of the raw materials. After three-dimensional printing, the performance of the prototype is similar to that of the raw material. It also needs to be considered that 3D printed prototype parts are usually anisotropic because of the layered nature of the process.

3. The process tolerance of CNC prototype parts is smaller.

4. CNC prototype has better surface finish

If only tolerance and finish are considered, CNC prototype is undoubtedly the best choice. However, considering the comprehensive factors such as cost, manpower and delivery time, 3D printing technology has obvious advantages. Therefore, when adopting 3D printing technology, the design considerations include:

(1) Prototype part size and order quantity. Mass production of small parts is more economical;

(2) Prototype part size and design complexity. Small and medium volume parts with medium and high complexity are the most ideal;

(3) Prototype part surface area and frame volume. The larger the surface area per cubic inch, the more features.

Driving factors:

(1) Fast and efficient product delivery;

(2) Ensure that multiple design iterations can be carried out;

(3) The design can be changed.