How to Shrink an STL File!
We recently had an issue loading some files into TinkerCAD because they were too big. TinkerCAD only permits files that are 25 MB or smaller to be uploaded. We were constructing a totem pole for my daughter’s social studies project and were trying to manipulate some existing models we found on Thingiverse into a totem pole.
We tried various online utilities – but they did not work for us. We found a free solution that was surprisingly easy to manipulate the STL files so they were a smaller size and could be uploaded to TinkerCAD.
The easiest way to reduce an STL file is to use Microsoft 3D Builder (Free on Microsoft Store) and SIMPLIFY the model. With the FREE tool you can reduce the face count – or number of vertices of the 3D model. This makes the face (surface) less smooth – but can dramatically reduce the size of the STL file as well. Below, we outline, step-by-step, how to use Microsoft 3D Builder to reduce the file size of your 3D model that is STL format.
STL File Format
STL = a file format for 3D models created by the Albert Consulting Group for 3D Systems in 1987. STL stands for StereoLithography. Common backronyms for STL include Standard Triangle Language or Standard Tessellation Language.
STL is a file format for 3D models that represents the surface geometry of the object as triangular surfaces. The more triangles that cover the surface – the smaller each triangle will be and the smoother the surface of the model will appear.
The goal in reducing the size of an STL file for any particular 3D object is to reduce the complexity of surface by reducing the total number of triangles representing the surface and increasing the size of each triangle (or “face”). Although this makes the surface appear less smooth – having a smaller file size for any given 3D object can:
- greatly reduce the storage space required for a model
- make it easier to share/send the model
- make for quicker upload times to 3D printing services
- not bog down older/less powerful computers that can’t handle manipulating large files
- allow you to upload 3D models to online applications like TinkerCAD that would otherwise exceed their upload limits
- achieve the “low poly” look you might want to have on a model for stylistic purposes
How to Use Microsoft’s 3D Builder to Reduce the STL File Size of Your 3D Model/Object
1) Download & Install 3D Builder from the Microsoft Store
As I indicated – Microsoft 3D Builder is a free program/app that is available for download at the Microsoft Store. You can download it HERE.
2) Open the STL File You Want to Reduce in File Size With Microsoft 3D Builder
Select “Open” from the menu that comes up when you first open Microsoft 3D Builder – as I have indicated in the picture below.
3) Select “Load Object” From the Menu
4) When the Model Opens in 3D Builder – “Import” It
5) Select “Edit” from the Main Menu
6) Select/Click on the Model & Then Select “Simplify”
7) Use the Slider to Reduce the Faces/Vertices of the Model & Then Click “Reduce Faces”
8) Select the Main Menu & Then “Save As”
Conclusion
In this instance, we wanted a rougher appearance to the whale (the “low poly” look)- since it was to look like a Native American carving on a totem pole. The size of the STL file was GREATLY reduced from 34 MB to just 205 KB! A whopping 99+% reduction in the file size. With this drastic reduction in STL file size it was very easy to import the model into TinkerCAD to manipulate it and use it for our purposes!
Please note – We could have just reduced the model’s file size by something like 50% and kept the it close to the same smoothness as the original model. It is really similar to the trade-off you make when reducing image sizes and quality for blog posts – in the interest of having them load faster.
I hope you found this to be helpful!
Oh, and here is an image of Annie’s totem pole!
Sincerely,
