SolidWorks Add-in Development
From a VBA Macro to Professional CAD Automation
A SolidWorks automation project that builds the rear door frame of truck and trailer bodies from a handful of dimension inputs.
Automation Layers
Live Demo
Rear Frame Automation
A recording showing the automation flow from dimension entry through to model update.
In This Article
This page tells the story of the software that automates the rear door frame of truck and trailer bodies. I started it to shorten the repetitive SolidWorks work I did every day as a draughtsman; over time the solution evolved from a VBA macro into a professional add-in.
The goal is not to change SolidWorks; it is to speed up and automate the work a draughtsman and designer repeat every day, and to simplify the process while keeping the same quality.
The Problem
Different dimensions kept arriving from production, and as the draughtsman I had to tackle the rear frame from scratch each time. The same steps repeated, and preparing the drawings and outputs was a separate burden on top.
- Modelling the rear frame from scratch on every new order
- Repeating the same dimension and geometry steps by hand
- The checking burden and error risk in dimension entry
- Having to revisit many parts when a single dimension changes
- Preparing drawings and production outputs separately
- No standard design flow across the team
First Solution: VBA Macro
The first step was a VBA macro. The user entered dimensions, the macro wrote those values into the assembly, the model updated itself, and the repetitive steps were managed from one place. This was not a “script”; it was automation genuinely needed in the field.
Dimension entry
The operator or draughtsman enters the required dimensions.
Parameter transfer
Values are written automatically into the relevant assembly dimensions.
Model update
The 3D model updates itself to the new dimensions.
Output preparation
Drawings and production files are gathered in the same flow.
From Macro to Add-in
A macro may work; but as usage grows, so do the needs for interface, sustainability, and deployment.
In time, doing the calculation was no longer enough. I wanted a tidier interface, a cleaner code structure, and a permanent tool inside SolidWorks. So I moved the solution to a C# / .NET add-in architecture.
Manual work → VBA → Add-in
- 1
Manual SolidWorks
Modelling and drawing work repeated on every order
- 2
VBA Macro
The first version that gathered the rear-frame calculation into one flow
- 3
Parametric flow
Dimension-driven assembly updates
- 4
C# / .NET Add-in
A tidier interface and a sustainable structure
Technical Architecture
SolidWorks API
Programmatic access to models, assemblies, and dimensions; working directly inside the design session.
C# / .NET
Add-in development, modular structure, error handling, and a foundation that can be extended later.
Parametric assembly
Incoming dimensions propagate through the assembly in a controlled way; there is no need to rebuild the model for each variant.
SolidWorks interface
With the CommandManager / Command Tab, the tool stays inside the CAD environment you already use.
Before / After
What changed in the daily SolidWorks workflow?
Before
- Check the dimensions one by one
- Open the assembly, change parameters by hand
- Re-check the parts and their mates
- Prepare each drawing separately
- Repeat the same steps for every order
After
- Enter the dimensions on one screen
- Run the calculation
- Let the model update automatically
- Follow the standard flow
- Prepare the outputs production needs
Practical Gain
The gain here is not a slogan; it is a difference in speed and order that is felt on the shop floor. Repetitive modelling and drawing work gets shorter, the flow becomes standard, and dimension changes are managed more predictably.
Feedback
SolidWorks Türkiye's congratulations and feedback on the project.
SolidWorks Türkiye
After the project was shared on LinkedIn, SolidWorks Türkiye specifically congratulated the work. They both commented on the post and sent feedback by direct message, describing the automation approach as a valuable example.
Congratulations on LinkedIn
The official SolidWorks Türkiye account congratulated the project and left feedback about the post being cited across their own social channels.
Support by direct message
A direct message in the same period described the macro approach — customising SolidWorks to fit a specific need — as a valuable application example.
This feedback does not constitute an official approval, certification, or endorsement. It is genuine external feedback showing the project was noticed in the CAD automation field.
If you would like to see the comments and project context at the source:
See the post on LinkedInLessons
- Automating daily design work with the SolidWorks API
- Moving from a macro prototype to an add-in architecture
- Parametric assembly and configuration logic
- Listening to a shop-floor need and turning it into software
- How much the user interface matters for adoption in the field
Conclusion
If you carry a similar repetitive workload as a draughtsman or designer, shortening it with software is possible. We can talk through how it might be automated.
Frequently Asked Questions
Common questions about SolidWorks add-ins, macros, and CAD automation.
What is a SolidWorks add-in?
A SolidWorks add-in is a software component that runs integrated inside the program and adds tools, automations, and interfaces specific to the CAD environment.
What is the difference between a SolidWorks macro and an add-in?
A macro is ideal for a quick start and urgent needs on the shop floor. An add-in is better suited to a tidier interface, a sustainable code structure, and long-term use.
What is the SolidWorks API for?
It lets you reach models, assemblies, dimensions, drawings, and output processes with code. It is the foundation of automating repetitive SolidWorks work.
Which languages can a SolidWorks add-in be built in?
The most common choice for add-in development is C# with .NET. VBA macros can also be used at the first prototype stage.
Why convert a VBA macro into a C# add-in?
As usage grows, so do the needs for interface, error handling, modularity, and deployment. A macro is a useful start; an add-in becomes the long-term solution.
What does CAD automation gain a draughtsman or designer?
It shortens repetitive modelling and drawing work, creates a standard flow, manages dimension changes more predictably, and speeds up production preparation.
Why does parametric design matter?
It lets you keep the same assembly logic across different dimensions. Instead of rebuilding the model every time, you update the existing structure.
How is SolidWorks automation used on the production side?
It can be used to prepare documents such as drawings, PDFs, DXF/DWG files, and flat-pattern outputs together with the design parameters.