For different printing models and different printing materials, choosing the appropriate 3D printing wall thickness often makes engineers very confused. However, Matrixlaser has put together a few tips for you, that will help you avoid bad surprises in your printed products and ensure that your printed objects have the maximum or minimum wall thickness you need.
1. Specify wall thickness for 3D model
First and foremost, it is important to specify the wall thickness for each surface of your 3D model. When using different software for 3D design, maybe the software allows the model wall thickness to be zero. However, the 3D printer needs to know exactly what wall thickness you want the object to have. Therefore, before sending the 3D model to the printer, the wall thickness must be specified
Wall thickness is the distance between one surface of the model and its corresponding surface. Many printing problems are caused by wall thickness. The minimum printable wall thickness is primarily determined by the type of material being printed. However, other factors such as orientation, size, and overall model design also affect the recommended minimum print wall thickness.
Before you print a product (ideally before you start designing a prototype), you need to know some basic principles for choosing printing materials. How to choose the appropriate wall thickness for each material is detailed in the article “3D Printing Design Specifications.”. Below, we look at some typical examples.
2. Select the appropriate minimum wall thickness
If you print on high-strength materials such as stainless steel (0.3mm) or titanium (0.4mm), the minimum allowable wall thickness will be very thin. But we always recommend making the wall as thick as possible from a safety perspective.
As mentioned before, the minimum wall thickness is very dependent on the structure and design of the 3D model. If you wish to use stainless steel, a vertical wall thickness of 5mm² only requires 0.3mm, a vertical wall thickness of 100mm² is at least 1mm, and a horizontal wall thickness of 100mm² requires a wall thickness of 2mm. In this case, surface size and orientation (horizontal or vertical) are critical in determining the minimum wall thickness.
When printing materials that are relatively brittle (such as ceramics), the general principle of making the model stronger still applies. An object with dimensions close to 50mm x 50mm x 50mm can accept a minimum wall thickness of 3mm, while a model of 100mm x 100mm x 100mm requires a minimum wall thickness of 6mm. For larger models, we recommend a wall thickness greater than 6mm.
3. Choose the appropriate maximum wall thickness
After concentrating on solving the problem of too little wall thickness, you may encounter the problem of too much wall thickness. For materials such as ceramics and metals, it is especially important to select the maximum wall thickness. Because thick sections will produce greater thermal stress, it will cause cracks or even breakage in the product.
Too much wall thickness may be the reason why we cannot print your product. The best solution to this problem is to shell the model and leave holes for the powder to pour out. Similarly, certain rules must be met when selecting the size of the holes. For stainless steel materials, small models (less than 10×10×10mm) require 3mm holes, larger models require 5mm holes, and for ceramic materials, the opening diameter is at least 10mm.
4. Recommended wall thickness for 3D printing
Even though a 3D printer can print very thin walls, that doesn’t mean printing very thin walls is a good choice. Parts with a wall thickness of less than 1mm are easily damaged during transportation and polishing. Here, we again recommend that you add additional wall thickness. A wall thickness of 2–5 mm will make your model stronger and safer.
For some materials (such as full color), long, heavy suspended structures can easily break if designed to be too thin. If your model includes more brittle structures (such as a human figure’s outstretched arms), try to add support structures into the product design. Don’t ignore the influence of gravity when designing the model. We recommend using a curved arm or letting the arm hold something (such as a shovel) to support it on the ground.
Let’s look at one last example where maximum wall thickness plays an important role. For example, if you want to print a flexible object (such as an iPhone case) using nylon, if the wall thickness is too large, the flexible object will look too bulky. In this case, a wall thickness of 1.5–2.5 mm is ideal for creating flexible objects.
5. Summary of choosing the perfect wall thickness
1) First, you need to know how to specify the wall thickness for each surface of the 3D model. This step is different for different modeling software, but it is extremely important when preparing a 3D printing model.
2) The choice of wall thickness is closely related to the type of printing material. Carefully study the wall thickness design principles for each material, and don’t forget that too much wall thickness can cause problems in some cases.
Suggestions on the selection of commonly used 3D printing materials, such as photosensitive resin
3) Carefully analyze and think about your design. If the 3D model has weak structures, find ways to support them. Keep in mind how the size of the object affects the choice of wall thickness.
