• Dr Izhar Aziz

Fix your CAD data for 3d printing

Getting a good CAD data or any electronic data is really important. If you have any experience printing 3d models or designing one you surely can understand how crucial it is to repair the data once you convert to STL format. The models may look perfect but it will fails during printing. To ensure a successful print you have to make sure your 3D file is good. Below shows 5 ways to fix your 3d files and common mistake that may slip our eye during data preparation;

1. Intersecting and overlapping triangles - when triangles intersecting you will have to cut off the 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 thus cause the printer failed to calculate the production path. When this happens an edge of triangle is shared by more than two face. 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 continue to print your model with two identical edges on top of one another. MAGICS software from materialise can do this by getting rid of the calculation problem through removing the duplicates triangles

2. Check wall thickness - this is one of the most common issues that caused failed print. 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 other hand and on the other hand thin enough to save as much material as possible.

3. Minimise file size - every triangles you design 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 wont even be able to print a file over a certain amount of polygons making triangle reduction or mesh decimation an essential component

4. Rescale your model - first, since STL files dont 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 influence the price. Finally, parts are often rescale for compensating shrinkage when printing

5. Hollow parts - 3d printing can be a costly business so as to waste less material while printing, you can hollow out your entire 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