Skip to Main Content
Fairfax County logo

3D Printing

Last Updated: Sep 23, 2024 1:58 PM

Resizing 3D Files in Windows with 3D Builder

If you're using a Windows PC then Microsoft has a free 3D shape editor app that lets you resize, rotate, or lay out multiple objects into an .STL file for printing with FCPL. Most of our 3D printers will accept files about 150mm wide, 150mm long, and 140mm tall so larger objects may need to be shrunk down to print successfully. 

Open "3D Builder" or download it for free from the Microsoft Store. You can create a new "scene" or open an existing file and then check Import Model.

Screenshot of 3d builder

Screenshot of 3d builder

The interface may look complex at first but to make the object smaller click it and the Scale button at the bottom. The dimensions of the original file will show in millimeters and now either drag the edges of the box to make it smaller or click one of the values and set it manually to the necessary size. The lock icon will keep the ratio of the length, width, and height proportional as you change one of the dimensions, this is useful if you just want to change the size of an object without skewing its shape.

Screenshot of 3d builder

Screenshot of 3d builder

The puzzle piece is now 35mm wide which has changed the other dimensions to maintain the shape of the object so click Accept. The Undo and Redo arrows in the top right hand corner let you go back if you make a mistake.

If that's all the changes needed then we're ready to save the shape as an .STL file for printing. Clicking the options or "hamburger" button in the top left hand corner brings up the Save As menu where you can choose where to save, the file name, and change the file format to .STL for submitting on our 3D printing page.

Screenshot of 3d builder

Fairfax County seal