Designing a 3D model is not easy. And, all too often a single flaw can lead to serious production problems or a completely defective final product. The good news is, most of the typical design errors that lead to flaws can be avoided. Here we’ll tell you how.
Additive manufacturing, commonly referred to as 3D printing, has opened up countless possibilities for businesses and individuals to create amazing things. Of course, the first step to 3D printing anything is generating the 3D model that the machine will work from. Easier said than done. It may surprise you, but even the most experienced 3D modeler can fail to create a model free of flaws. That is because 3D modelling is a technically complicated process. Not only do you have to consider the model itself, but also the properties and restrictions of the production method, as well as the material you select. It’s a long road from idea to product, but 3D printing services like ours can make the journey easier.
At trinckle we strive to make getting from model to finished product a simple, reliable, and dare we say fun process. When you upload your 3D model to our 3D printing service, our in-house developed model repair software automatically checks for any model flaws. Before your models are sent to print, our experts take a final look to make sure they are production ready, guaranteeing you a perfect print. But of course, the best way to avoid production problems or delays is to avoid potentially problematic designs altogether. To help you do this we’ve assembled a list of 7 design musts to help you create perfect 3D models.
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1. Make sure your model walls are thick enough
Obvious as it may seem, sometimes wall thickness is forgotten in the design process, which can lead to serious production problems. The wall thickness is a crucial determining factor for the strength and stability of a 3D printed object. If the walls are not thick enough, the model could very well collapse.
Unfortunately, there is no one golden value for wall thickness that works perfectly in every case. Rather the minimum thickness is dependent on the material you select for your object, so make sure you plan accordingly. If you need to learn more about material properties visit our materials page.
2. Eliminate unmatched edges
Holes are a serious problem for a 3D model. Printers cannot make sense of them and if any appear, then the 3D model will be marked as defective. The more unconnected edges there are, the harder it is for even our repair service to address this issue.
Whether a single opening between the edges of two triangles or a completely missing section, these flaws are guaranteed to slow your progress down. But, there are great tools that will help you fix these problems before you send your 3D model away to print. For example, you can use the free software netfabb to analyze your model and use the repairing tools to eliminate unmatched edges.
3. Righting flipped normals
In order to create a 3D printed object, the model has to contain all the necessary information the machine will need for processing. Of particular importance is defining inside and outside for your model.
In a 3D model, each and every triangle comes with a piece of information which marks its inside and outside. The triangles are marked with imaginary arrows, called normal vectors, that indicate the correct orientation. Sometimes a single triangle or an entire section of a 3D model is flipped. For the printer, this is a problem and either you will end up with errors or it won’t print at all. There are many software tools you can use to check your 3D model for flipped normals, for example our model repair software automatically checks for and repairs flipped normals. Try to ensure that it is 100% clear which triangles point to the outside and which to the inside.
4. Ensure there is enough clearance
You put a lot of time and thought into every detail of your 3D model. That is why you need to make sure there is enough distance between the individual components. When different parts are too close together, it can result in these parts fusing together during production. Not only could this structurally ruin your model, but it also means that those details you worked so hard on can disappear.
To avoid this problem altogether make sure that there is enough clearance between every part of your model. For the best results, we recommend that there be at least 3.0 mm between the individual model features.
5. Get the dimensions right for moving parts
The relationship between two parts designed to have a mechanical function is called fit. And, in order to guarantee fit, there are certain design guidelines you will need to follow. The alternative: parts that simply do not work. So, what do you need to consider? The inner diameter of one part must be bigger than the outer diameter of the other part. Generally, a difference in diameter of 0.5 mm to 1mm will suffice.
Furthermore, not every method is suitable for the production of moving parts. Makes sure you choose both material and process carefully. Here are some that are well or partially suited for moving components:
- These methods and materials are suitable or partly suitable for moving parts:
- Plastic Sintering (Polyamide, white, dyed)
- Alumide Sintering (Alumide)
- Extruded Plastic (Thermoplastic ABS)
- Resin-bonded Plaster (Plaster)
- Resin-bonded Plastic (Grained Acrylic)
- Rubber Sintering (Thermo-PU)
6. Include escape holes
Escape holes are a crucial element of 3D objects with hollow spaces, and as with everything you need to incorporate this design information in your 3D model. Not only can the failure to include escape holes lead to higher prices, but also structural problems for your model. Depending on the size of your model you may need more than one escape hole. If you decide to incorporates a single hole, it should have a diameter of at least 10 mm. If the holes in your model are too small, you can increase their diameter or scale up the entire model.
When it comes to escape holes, keep it simple. Decide if you really need hollow spaces. If not, remove them entirely. But, if you do need to keep them make sure that they are easily accessible so that excess material can be removed.
7. Add supports to avoid warping
Very often long and thin components of a 3D printed object become warped in production. In order to avoid this, you can make changes to your 3D model. A simple fix can be to increase the wall thickness of the part in question, which can improve stability. Another alternative is to add support beams to the part, these would then be removed in post-production.
As a general rule, when you are using laser sintering to create your part it is good to avoid mixing thin and thick structures in a single part. This has a very simple reason; the more intense heat required for the thicker parts will damage the thinner ones.
We hope that these 7 design musts for perfect 3D models will help you avoid some of the errors we see most often. If you have other design related questions, visit our design guidelines page. You can also find detailed information on materials and production methods in our help section.
If you can’t find the answer you are looking for, get in touch with our customer support. We’re happy to help you get the perfect print: support@trinckle.com