how to modify stl files in solidworks

3 min read 21-01-2025

Modifying STL files within SOLIDWORKS isn't a direct process like editing native SOLIDWORKS parts. STL (Stereolithography) files are essentially surface meshes, lacking the parametric history of SOLIDWORKS parts. This means you can't directly edit features. However, you can import them and then use various tools to modify their geometry. This article explores several methods to achieve this.

Importing the STL File

Before modification, you need to import your STL file into SOLIDWORKS.

Open SOLIDWORKS: Launch your SOLIDWORKS software.
Insert > Import: Navigate to the "Insert" menu and select "Import."
Browse: Locate and select your STL file.
Import Options: SOLIDWORKS offers several import options. Choosing "Import as a Solid Body" is generally recommended for most modifications, although "Import as a Surface Body" may be necessary for extremely complex or problematic meshes. Experiment to see what works best with your specific file. You might need to adjust the "Tessellation" settings (finer tessellation gives a smoother result but larger file size).
Import: Click "Import" to bring the STL model into your SOLIDWORKS part.

Methods for Modifying STL Files

Once imported, several approaches allow you to modify the STL geometry. These methods offer varying degrees of control and precision.

1. Using SOLIDWORKS Features Directly

While you cannot directly edit the original STL mesh, you can use various SOLIDWORKS features to create new geometry based on the imported STL. This includes:

Extrude/Revolve: Create new features by extruding or revolving sections of the imported STL. This is helpful for adding simple extensions or creating rotational parts. Remember to use appropriate selections. You can select faces or even a whole body to begin creating your new geometry.
Shell: Create hollow parts from the solid STL import by defining a shell thickness.
Cut-Extrude/Revolve: Subtract material from the STL using cut-extrude or cut-revolve features. This allows for precise removal of sections.
Wrap: This command lets you wrap the imported STL over a surface, generating a solid model that conforms to the original STL’s shape but adjusted to your needs. This is a powerful way to make precise modifications.

2. Repairing the Mesh

Often, STL files contain errors or inconsistencies. Before modifying, it's crucial to repair these issues:

SOLIDWORKS Mesh Repair Tool: SOLIDWORKS has a built-in mesh repair tool accessible through the right-click menu when selecting the imported body. This attempts to fix common issues like holes, gaps, and non-manifold geometry.
Third-Party Software: For more complex repairs, consider using specialized mesh repair software before importing into SOLIDWORKS. Netfabb is a popular choice.

3. Converting to a Solid Body

For more advanced modifications, converting the STL to a solid body is often necessary. This process can lead to some loss of precision but greatly increases editing capabilities:

Import as Solid: As mentioned earlier, importing as a solid body is preferred in many cases.
Feature Creation: Once imported as a solid, the methods from section one become fully available.

Important Note: Converting a complex mesh to a solid body can take significant processing power and time. Be patient and have enough RAM available.

4. Using the "Simplify" Command

For extremely high-polygon meshes, the "Simplify" command can reduce the number of faces, making the file more manageable. However, this can result in a loss of detail. This can be found under the "Evaluate" section of the SOLIDWORKS menu.

5. Combining with Other Parts

Import the STL as a reference geometry then use it to create new features. For example, you can create a new part that perfectly matches the contours of the imported STL by using it as a reference for creating curves or surfaces.

Exporting the Modified Model

After modifications, you can export the model in various formats, including STL, STEP, or SOLIDWORKS native formats. Export as a format suitable for your next steps in the design process.

Troubleshooting

Mesh Errors: Address any mesh errors before modification to ensure accurate results.
Processing Time: Complex STL files can require considerable processing time.
Loss of Detail: Converting to a solid body or simplifying the mesh may cause a loss of detail. Consider your priorities in terms of fidelity and ease of editing.

By understanding these methods, you can effectively modify STL files within SOLIDWORKS, adapting them to your design needs. Remember to always back up your original file before making any modifications.