How to Prep an STL File for Printing

3D printing is great for prototyping, making spare parts and even end use production. But before you hit print on your machine, it’s a good idea to make sure that the file you’re outputting is fully optimized. But, how exactly do you optimize a .stl file so that it is ready to print?

In this article I’ll walk you through some best practices for exporting a .stl from SolidWorks, Solid Edge, Creo and Inventor.

STL files are the standard file type for 3D printing

As you probably know, the .STL file type is shorthand for both STereoLithography, and Standard Tessellation Language. For now, .stls are the defacto standard file type for 3d printing (though some believe the .AMF file format should supplant the current standard).

When you export a .stl of your 3D model, you’re exporting a raw and unstructured representation of your model’s surface geometry. While the term unstructured might seem a bit offputting its really just a way of saying that a .stl is a random assortment of triangles that accurately assemble in a 3D Cartesian coordinate system to make a mesh of your part, without regard for symmetry.

One other thing to keep in mind is that .stls can be exported in two formats, ASCII and Binary. Binary files are by far the most popular among most users solely because they are more compact.

With that info in mind, lets get to exporting!

Exporting a STL from Solid Works

In Solidworks exporting a .stl file requires the following steps:

1.     Once you’ve finished your model choose the File menu and select “Save As”

2.     Set your file type to .STL

3.     Click the “Options” button in the bottom right-hand corner of the “Save As” dialogue box.

4.     Choose the “Fine” detail setting

5.     If you’re feeling adventurous you can also click the “Custom” detail setting.

6.     If you do choose “Custom” change the “Deviation” to 0.0005in (0.01mm) and the “Angle” variable to 5 degrees or lower.

7.     Click Save

Exporting a STL from Inventor

Like Solidworks, Inventor also offers a very simple method for exporting .STL files. While Solidworks gives you much better control over how fine your .stl can be, Inventor’s saving options are a bit more limited.

1.     1. Once you’ve finished your model choose the File menu and select “Save Copy As”

2.     Set your file type to .STL

3.     Choose the Options button in the “Save As Copy” dialogue box.

4.     Choose “High” for your level of detail

5.     Save

Exporting a STL from Creo

Creo’s method for exporting a .stl is very similar to SolidWorks’ method. In Creo you are given a greater degree of control over your model, which in the right hands can render great results.

1.     Once you’ve finished your model choose the File menu and select “Save As” and then “Save as a Copy”

2.     Change your file type to .stl

3.     Name your file

4.     Click OK… An “Export STL” dialogue box should appear

5.     Change the “Chord Height” variable to “0”

6.     Change the “Angle Control” variable to 1

7.     Click OK

Exporting a STL from Solid Edge

1.     Once you’ve finished your model choose the File menu and select “Save As”

2.     Change your file type to .stl

3.     Choose the Options button in the “Save As” dialogue box.

4.     Update your “Conversion Tolerance” to 0.015 or lower

5.     Update your “Surface Plane Angle to less than  45°

6.     Select “Binary” File type

7.     Name your File

8.     Click “Save”

Now that you’ve got your best practices in place, your 3D prints should turn out as close to their parent 3D models in shape and size as is possible. If there are any other softwares that you’d like for me to develop best practices for, just leave me a note in the comments section. 

Also, stayed tuned. In short order I’ll be publishing another feature on Advance Post Processing of STLs for 3D printing. In that article we’ll delve into repairing broken .stl meshes and further optimizing geometry for truly remarkable 3D printing results.