Kirsten Van Praet January 30, 2018

If you have some experience with designing and printing 3D models, you know how important it is to repair your 3D file after conversion from CAD to STL. The design may look perfect, but when you start printing it, the build can fail. An error can easily slip the eye, which is why STL editing software can help you avoid printability issues and ensure a successful print. Discover the STL repair and editing tools you need to create a watertight, printable 3D model: and they’re all available in Materialise Magics software.

1. Trim or unify intersecting and overlapping triangles triangles.png

A common problem that novices in 3D Printing may come across is triangles cutting each other. When triangles intersect, you will have to cut off the sharp edge and trim the triangles to obtain a unified design. If you forget to do this, the 3D printer will get confused again about the inside and outside of your model and will not know what part of the bounding box to fill up, resulting in a failed print.

Triangles can also overlap. When this happens an edge of a triangle is shared by more than two faces. In this case the printer will have a hard time calculating the production path. It’s not clear to the machine what it needs to do, so it can slice your model in a way that the laser or nozzle simply continues to print your model with two identical edges on top of one another. Materialise Magics software removes the duplicates that are part of the overlapping triangles, thereby getting rid of the calculation problem and ensuring that you have a unified solid model.


2. Check wall thickness

Fun fact: 1 in 5 orders received in 3D printing bureaus have to be cancelled due to incorrect wall thickness. It’s exceedingly common, and it’s a very important part of your design that you need to get right. When using 3D modeling software, it is possible to design a surface without implementing wall thickness. However, the 3D printer will need information about how thick you intend the wall of your object to be.

It’s a bit of a balancing act: the proper wall thickness means that you need surfaces which are thick enough to be 3D printed successfully and contribute to a strong, printed part on the one hand, and on the other hand thin enough to save as much material as possible. With Materialise Magics, you can analyze wall thickness and fortify the walls where needed.


3. Minimize file size

Every triangle your design is made up of uses memory in your computer. Therefore, STL files with more triangles are heavier to process and slice. In many cases, the 3D printer won’t even be able to print a file over a certain amount of polygons, making triangle reduction –also known as polygon reduction or mesh decimation - an essential component.

4. Rescale your 3D model

When can rescaling a 3D model be useful? First of all, since STL files don’t contain distance unit information, you can use a rescale tool to rescale your model to the right unit and size. Secondly, to overcome some wall thickness issues, you can shrink or enlarge your model to the appropriate size. Thirdly, when ordering your 3D Print, size influences the price you will pay. And finally, parts are often rescaled for compensating shrinkage when printing.


5. Hollow parts

3D Printing can be a costly business, so to waste less material while printing, you can hollow out your entire model. With Materialise Magics, you can hollow models while maintaining the freedom of deciding the optimal wall thickness for printing. This ensures that the printed version will be as economical and environmentally friendly as possible, while still retaining its optimal structural integrity and great looks. 

And there’s more in this free whitepaper!

Want to discover 5 more tips on how to handle data preparation like a 3D printing pro? We’ve put together our top trusted tips and tricks in this whitepaper so you can print error-free, build after build.

Download a free copy

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