How to export an STL file for 3D printing

An STL file describes the surface of your model as thousands of small triangles. It is what our quote tool reads to work out print time and price. Here is how to export one from the apps our customers use most.

Autodesk Fusion

1. In the Browser panel on the left, right-click the body or component you want to print.
2. Choose Save As Mesh.
3. Set Format to STL (Binary) and Unit Type to Millimeter. Set Refinement to High.
4. Click OK and choose where to save the file.

Tinkercad

1. Open your design and click Export at the top right.
2. Choose whether to include everything in the design or only the selected shapes.
3. Under "For 3D Print", click .STL. The file downloads straight away.

Tinkercad always works in millimetres, so the size will be right.

SolidWorks

1. Go to File → Save As.
2. Set "Save as type" to STL (*.stl), then click Options.
3. Choose Output as Binary, Unit Millimeters and Resolution Fine.
4. Click OK, then Save. For an assembly, tick the option to save all components to one file only if they are meant to print as one piece.

Onshape

1. Right-click the part in the parts list, or the Part Studio tab, and choose Export.
2. Set Format to STL, STL format to Binary, Units to Millimeter and Resolution to Fine.
3. Click Export to download the file.

SketchUp

1. In SketchUp for desktop, go to File → Export → 3D Model and choose STL as the file type.
2. Click Options and set Export unit to Millimeters.
3. In SketchUp for web, use Download → STL instead.

SketchUp models often have gaps or faces with no thickness. If the quote tool rejects your file, see our STL checklist.

Blender

1. Select the object you want to print.
2. Go to File → Export → STL (.stl).
3. Tick Selection Only, and check the Scale setting before you export.

Blender works in metres by default, and printing software reads STL numbers as millimetres. A 10 cm model made at real size in Blender can therefore arrive as a 0.1 mm speck. If your scene is in metres, set Scale to 1000 when exporting.

Check the size before you upload

When you upload, the quote tool shows your model's dimensions. If a part you expected to be 50 mm long shows as 2 mm or 1,270 mm, it was exported in the wrong units. Re-export it in millimetres and upload again. You can also paste a MakerWorld model link instead of uploading a file.

Upload your STL