The demand for 3D printing metal is increasing, but 99% of people don’t know how to design metal 3D printing!

Before introducing the design rules for metal 3D printing, I need to clarify one point. When discussing metal 3D printing production, it's not about replacing existing parts. This is a common misconception. In the vast majority of cases, metal 3D printing doesn't offer advantages when it comes to producing existing parts. Whether it's machining, casting, sheet metal, or welding, traditional processes are highly mature. For traditional parts that can be manufactured using traditional processes, metal 3D printing doesn't offer advantages in terms of cost or efficiency. Of course, if you simply want to create a prototype, metal 3D printing still has its advantages. It's fast and can use the same materials as the final product. This is a more traditional application of metal 3D printing.

Metal 3D printing aims to reduce overall costs through metal 3D printing design. Metal 3D printing aims to achieve four main goals:

Reducing the number of parts; Reducing weight; Reducing assembly; and Producing highly complex parts. By achieving these "three reductions and one improvement," overall costs are reduced.

For example, General Aviation launched an online metal 3D printing design competition. For a part on an existing aircraft weighing 2033 g, the public was invited to submit 3D printing designs that met strength and assembly requirements. The lighter the design, the better. The lightest design was the winner. The competition attracted a large number of participants. One of the greatest benefits of 3D printing is the design freedom it offers.

Most of the designs presented by the contestants met the original constraints, satisfying assembly and strength requirements while significantly reducing weight. The winning entry weighed 327 g, almost one-tenth of the original weight—to be exact, 16%! This is undoubtedly a revolution for the aviation industry, where every inch counts. Every 1,706g of weight reduction equates to hundreds of thousands of yuan in fuel costs and tens of thousands of tons of carbon emissions annually. This represents the comprehensive cost of 3D printing, not just manufacturing costs, but a comprehensive approach that takes into account all the benefits. This is a significant advantage for the aviation industry, which is in a strong demand for weight reduction. Metal 3D printing offers similar comprehensive cost advantages beyond aviation. The use of mobile cooling molds, enabled by metal 3D printing, offers similar comprehensive cost advantages, which I'll discuss in more detail when I have the opportunity.

Having discussed the important basic principles and goals, let's discuss some practical knowledge essential for metal 3D printing design. I hope it will provide insights for your design process. These parameters may not correspond to manufacturer specifications; most are derived from practical experience. For example, a manufacturer may say 0.2 for wall thickness, but in practice, 0.2 may not be stable. Additionally, the values ​​may vary between different types of 3D printers, but generally speaking, they shouldn't differ significantly.

First, metal 3D printing, like other 3D printing methods, requires the 3D digital file to meet basic requirements, such as solidity and watertightness. These have been summarized previously. Those unfamiliar with these requirements can refer to the 3D Printing Design Specifications for a review of the basic design specifications for 3D printing.

Let's discuss the specific requirements for metal 3D printing:

1. Minimum Detail Features

The minimum detail feature must be no less than 0.15mm. This means that features and details smaller than 0.15mm may be overlooked and not rendered. For example, for a 0.1mm slot, although the minimum spot size can be less than 0.15mm, details are distinctive and these features may be overlooked.

2. Minimum Wall Thickness

The minimum wall thickness can reach 0.2mm, but it is recommended not to be less than 0.5mm. The minimum wall thickness also depends on the structure of the object and the ratio of its height to wall thickness. Generally speaking, this ratio should not exceed 40. If it exceeds 40, deformation may occur.

3. Surface Finish

The roughness and smoothness of the surface are related to three factors:

A. Printing material;

B. Build parameters;

C. Part orientation.

In different printing situations, surface roughness, equipment, shape, and orientation all affect the surface finish. Generally speaking, vertical surfaces are better than tilted surfaces, and tilted upper surfaces are better than lower surfaces.

4. Support Structures

There's a long-held myth that supports aren't necessary when using powder 3D printing. This may be true for SLS plastics, but for metal 3D printing, supports are necessary, and often absolutely essential. The main functions of supports in metal 3D printing are:

A. Attachment to the build platform;

B. Maintaining the part's shape;

C. Preventing warping.

Therefore, metal 3D printing can generate a large number of support structures, which creates two problems: one is additional cost; the other is an additional process, primarily removing the supports. Sometimes, removing the supports can be incredibly tedious. After all, they're metal, not plastic, and sanding them can be a real pain. So what should we do? Should we just put up with it? The opposite is true. We should leverage the design freedom offered by 3D printing to design parts with fewer supports and better performance.

The angles created by supports can vary depending on the equipment and material. In most cases, relying solely on powder support to achieve the desired tilt angle is insufficient.

5. Overhangs

Overhangs occur when the upper layer of a part is larger than the upper layer. Metal 3D printing has a relatively low tolerance for overhang; overhangs greater than 0.5 mm can cause problems.

Internal holes generally have self-supporting structures, which generally have little impact on printing. This is very advantageous for producing molds with adaptive cooling. However, excessively large hole diameters can also cause problems. As shown in the figure, holes smaller than 8 mm generally achieve self-support, but larger than 8 mm can cause overhangs.

6. Bridging Structure

The allowable distance for the bridging structure is approximately 2 mm, which is relatively small.

7. Internal Stress - Warping

Internal stress is a common problem in metal 3D printing. Significant variations in the cross-section of the printed object can easily generate significant internal stress. Large, flat surfaces can also generate strong internal stress. These high levels of internal stress can even deform the build base and shear bolts. Therefore, when designing, avoid sudden changes from a small to a large cross-section; instead, adopt a gradual transition. Furthermore, avoid using large, flat surfaces. Think about it another way: if a relatively flat surface is required, why use 3D printing?

8. Other Design Tips

Metal 3D printing is well-suited for printing grid-like structures. These grid-like structures are ideal for internal supports, reducing weight while maintaining strength.

After printing, consider the removal of supports and powder. Ensure access for these removals to prevent supports from being permanently sealed inside the part.

Metal 3D printing has revolutionized the manufacturing industry, offering unparalleled design freedom and the ability to create complex, high-performance parts. As a leading provider of metal 3D printing solutions, Huateng Metal Products (Dongguan) Co., Ltd. remains at the forefront of this cutting-edge technology. In this blog post, we will provide a brief overview of design methods for metal 3D printing and offer insights and tips to help you master this innovative process.

When designing for metal 3D printing, it's crucial to understand the technology's unique capabilities and limitations. Unlike traditional manufacturing methods, 3D printing can create complex geometries and internal structures that are impossible with traditional methods. This opens up endless possibilities for creating lightweight yet strong components, making it an ideal choice for industries such as aerospace, automotive, and medical.

One of the key considerations in designing for metal 3D printing is the choice of material. Different metal powders have different properties and behaviors during the printing process, so it is crucial to select the most appropriate material to meet the needs of the intended application. Factors such as strength, heat resistance, and corrosion resistance must be considered to ensure that the final part meets the required specifications.

Another important aspect of designing for metal 3D printing is the use of support structures. Due to the layer-by-layer nature of the printing process, overhanging structures and complex geometries may require supports to prevent deformation or collapse during printing. Designing these supports in a way that minimizes post-processing and material waste is crucial to optimizing the overall efficiency of the manufacturing process.

Furthermore, understanding the capabilities of the specific metal 3D printing technology being used is crucial to achieving the desired results. Factors such as minimum feature size, surface finish, and build orientation can significantly impact the quality of the final part and should therefore be carefully considered during the design phase.

In short, mastering metal 3D printing requires a deep understanding of the technology, materials, and design principles. By leveraging the expertise of companies like Huateng Metal Products (Dongguan) Co., Ltd., manufacturers can unlock the full potential of metal 3D printing and stay ahead in today's competitive market. With the right design approach, metal 3D printing offers endless possibilities for creating innovative, high-performance components that push the boundaries of modern manufacturing.

In summary, metal 3D printing opens up new design options, liberates design freedom, and makes more designs a reality. However, metal 3D printing will not replace traditional manufacturing methods; each method has its own strengths and complements the other. Understanding the specifications of metal 3D printing is crucial to maximizing its benefits. I hope this article will be helpful to those who need metal 3D printing.