How to Cut-Extrude from Sketch in SolidWorks using VBA macro?

How to Cut-Extrude from Sketch in SolidWorks using VBA Macro?

Automating your SolidWorks design process can save time, reduce repetitive steps, and boost productivity. In this tutorial, you’ll learn how to create a Cut-Extrude feature from an existing sketch using VBA macro inside SolidWorks.

This step-by-step guide walks you through:

• ✅ Accessing SolidWorks via VBA

• ✅ Selecting a sketch

• ✅ Creating a cut-extrude

• ✅ Handling errors and validations

Let’s dive in.

🧾 Step-by-Step SolidWorks Macro with Comments

Full VBA Code – With Line-by-Line Explanation

Option Explicit

' Create a variable to store the SolidWorks application object
Dim swApp As SldWorks.SldWorks

' Create a variable for the active document (part/assembly)
Dim swDoc As SldWorks.ModelDoc2

' Create a variable to hold the created feature
Dim swFeature As SldWorks.Feature

' Boolean variable to check status of operations
Dim BoolStatus As Boolean

' Main subroutine starts here
Sub main()

  ' Get the current running SolidWorks instance
  Set swApp = Application.SldWorks
  
  ' Check if SolidWorks is running
  If swApp Is Nothing Then
      MsgBox ("SolidWorks is not opened")
      Exit Sub
  End If
  
  ' Get the currently active document (must be a Part)
  Set swDoc = swApp.ActiveDoc
  
  ' If no document is open, exit the macro
  If swDoc Is Nothing Then
      MsgBox ("SolidWorks document is not opened. Please open a document.")
      Exit Sub
  End If

  ' Attempt to select Sketch2 for extrusion
  BoolStatus = swDoc.Extension.SelectByID2("Sketch2", "SKETCH", 0, 0, 0, False, 0, Nothing, swSelectOption_e.swSelectOptionDefault)

  ' If selection fails, notify user
  If BoolStatus = False Then
      MsgBox ("Failed to select Sketch2.")
      Exit Sub
  End If

  ' Create a cut-extrude through all using selected sketch
  Set swFeature = swDoc.FeatureManager.FeatureCut4( _
      True, False, False, _
      swEndCondThroughAll, 0, _
      0.01, 0.01, _
      False, False, False, False, _
      1, 1, False, False, _
      False, False, False, _
      True, True, True, True, _
      False, swStartSketchPlane, 0, _
      False, False)

  ' If feature creation fails, alert the user
  If swFeature Is Nothing Then
      MsgBox ("Failed to create Extrude Cut Feature.")
      Exit Sub
  End If

End Sub

What Does This Macro Do?

✅ 1. Gets the active SolidWorks session

It starts by checking if SolidWorks is open and a document is active.

✅ 2. Selects “Sketch2”

It tries to select a sketch with the name "Sketch2" on the active part.

💡 Make sure “Sketch2” exists in the part before running the macro.

✅ 3. Creates a Cut-Extrude

Using FeatureCut4, the macro creates a cut through all from the selected sketch.

✅ 4. Adds Error Handling

Basic error handling ensures you don’t get stuck if something’s missing.

📌 Important Notes

• This macro only works in part documents (.SLDPRT)

• It requires Sketch2 to be pre-created and fully closed

• Modify "Sketch2" if your sketch has a different name

🔁 Example Use Cases

• Automate repeated cut operations

• Apply standard cut-outs to imported geometry

• Pre-process parts for downstream tasks

🧠 Final Thoughts

This VBA macro is a great example of how automation can simplify design workflows. Whether you’re processing hundreds of models or just saving clicks, a small macro like this can go a long way.

If you’re interested in:

• Customizing macros

• Creating sketches programmatically

• Full part design automation

Let me know — we’re building a full VBA & SolidWorks automation series for The Tech Thinker!

📥 Need Help?

Drop a comment below or contact us for custom macro development. We love building intelligent, reusable design tools!

Cut-Extrude from Sketch in SolidWorks using VBA

Step by Step Detailed Explanation

Step 1: Declare Variables

Option Explicit

Dim swApp As SldWorks.SldWorks              ' SolidWorks application
Dim swDoc As SldWorks.ModelDoc2             ' Active document (Part/Assembly)
Dim swFeature As SldWorks.Feature           ' Stores the created feature
Dim BoolStatus As Boolean                   ' Holds True/False status of operations

Explanation:
We declare the objects we’ll use in the macro — one for the app, one for the document, one for the feature, and a boolean to track success/failure.
This makes the code more readable and easy to debug.

🔹 Step 2: Start the Main Procedure

Sub main()

Explanation:
This is the starting point of your macro.
Everything you want to automate goes inside this subroutine.

🔹 Step 3: Get SolidWorks Application Instance

Set swApp = Application.SldWorks

If swApp Is Nothing Then
    MsgBox ("SolidWorks is not opened")
    Exit Sub
End If

Explanation:
This line connects the macro to your running SolidWorks instance. If SolidWorks is not open, it alerts the user and exits safely.

🔹 Step 4: Get the Active Part Document

Set swDoc = swApp.ActiveDoc

If swDoc Is Nothing Then
    MsgBox ("SolidWorks document is not opened. Please open a document.")
    Exit Sub
End If 

Explanation:
The macro checks if a file is currently open in SolidWorks.

It must be a part document (.SLDPRT) where the sketch is present. If not, it alerts and exits.

🔹 Step 5: Select the Target Sketch (e.g., “Sketch2”)

BoolStatus = swDoc.Extension.SelectByID2("Sketch2", "SKETCH", 0, 0, 0, False, 0, Nothing, swSelectOption_e.swSelectOptionDefault)

If BoolStatus = False Then
    MsgBox ("Failed to select Sketch2.")
    Exit Sub
End If

Explanation:
This selects a sketch named “Sketch2” in the model tree. You must make sure it exists. If the sketch is missing or misnamed, this block will fail gracefully.

🔹 Step 6: Create the Cut-Extrude Feature

Set swFeature = swDoc.FeatureManager.FeatureCut4( _
    True, False, False, _
    swEndCondThroughAll, 0, _
    0.01, 0.01, _
    False, False, False, False, _
    1, 1, False, False, _
    False, False, False, _
    True, True, True, True, _
    False, swStartSketchPlane, 0, _
    False, False)

Explanation:
This performs the actual Cut-Extrude. The sketch is cut through all the geometry in the direction specified. It doesn’t need to specify end depth because swEndCondThroughAll handles that.

📌 You can tweak parameters like:

0.01 = draft angles (not used if through all)

swStartSketchPlane = where to start the cut

True/False values = optional flags for merging, directions, etc.

🔹 Step 7: Check if Feature Was Created Successfully

If swFeature Is Nothing Then
    MsgBox ("Failed to create Extrude Cut Feature.")
    Exit Sub
End If

Explanation:
Just a final check to ensure everything ran successfully. If the feature wasn’t created, the macro informs you instead of silently failing.

Frequently Asked Questions (FAQs)

✅ What is a Cut-Extrude in SolidWorks?

A Cut-Extrude removes material from a 3D model using a 2D sketch. It’s used for holes, slots, cutouts, and other internal features.

✅ Can I automate Cut-Extrude using a macro?

Yes, you can automate it using VBA macros in SolidWorks. The macro selects a sketch and performs a cut automatically—saving you time on repetitive tasks.

✅ What sketch name should the macro use?

The macro looks for a sketch named Sketch2. You can update the macro to use any valid sketch name that exists in your model.

✅ What if the sketch isn’t found?

The macro will show a message: “Failed to select Sketch2.” It will safely exit without making changes to your model.

✅ Can I use this macro in assembly or drawing files?

No. This macro works only with part files (.SLDPRT). For assemblies or drawings, you need different macros.

✅ How do I run this macro?

1. Open SolidWorks

2. Open your part document

3. Press Alt + F11 to launch the VBA editor

4. Paste the macro

5. Run main()

✅ What does swEndCondThroughAll mean?

It’s an end condition that tells SolidWorks to cut through all geometry in one direction—ignoring cut depth values.

✅ How can I change the cut depth instead?

Replace swEndCondThroughAll with swEndCondBlind and set your desired depth value (e.g., 0.01).

✅ How can I check if the cut worked?

The macro checks if the feature was created. If it fails, you’ll get a message: “Failed to create Extrude Cut Feature.”

✅ Can I extend the macro to create sketches too?

Yes! You can add API calls to draw circles, rectangles, or any sketch entity before the cut operation.

✅ Is this macro safe to test?

Yes, but always test on a duplicate file or test part, and save your document before running any macro.

✅ How can I perform the cut in both directions?

You can modify the macro using swEndCondMidPlane or enable two-direction cut flags in the parameters.

✅ Where can I learn more about the SolidWorks API?

Refer to the official SolidWorks API Help Guide or visit the SolidWorks API Forums.

✅ Can I run this on SolidWorks Student Edition?

Yes, as long as macro functionality is enabled. Some institutions may restrict macro use for security.

✅ Can this macro be converted into a toolbar button?

Absolutely. You can embed this VBA macro into a button or convert it into a more advanced Add-In using VSTA or .NET.

🌐 Internal Reference

• SolidWorks VBA Extrude Feature: Automate Part Creation

🌐 External References

1. 🔧 SolidWorks API Documentation

• URL: https://help.solidworks.com/2024/english/api/sldworksapiprogguide/Welcome.htm

• Why use it? Official documentation for all SolidWorks automation functions and constants used in macros.

2. 💬 SolidWorks API Forum (Community Help)

• URL: https://forum.solidworks.com/community/developer/api

• Why use it? A great place for troubleshooting, sharing macros, and learning new techniques directly from the SW developer community.

3. 🎓 MySolidWorks – Tutorials & Training

• URL: https://my.solidworks.com/

• Why use it? Contains beginner to advanced tutorials, including macro-related guides and how-to videos.

5. 🔐 Microsoft VBA Reference for Office Automation

• URL: https://learn.microsoft.com/en-us/office/vba/api/overview/excel

• Why use it? Helps understand general VBA structure, error handling, and syntax used in SolidWorks macros too.