FreeCAD Overview
FreeCAD is a free, open-source, parametric 3D CAD application used for:
- Mechanical engineering
- Product design
- 3D printing
- CNC machining
- Architecture (BIM)
- Robotics
- Finite Element Analysis (FEA)
Unlike drawing programs, every feature is stored in a model history. You can edit dimensions at any time and the model automatically rebuilds.
Main Interface
The FreeCAD interface consists of several major areas:
| Area | Purpose |
|---|
| Menu Bar | Commands and settings |
| Toolbars | Quick access to tools |
| Workbench Selector | Switch between modeling environments |
| Combo View | Model tree and properties |
| 3D View | Main modeling window |
| Tasks Panel | Current operation controls |
| Property Editor | Edit dimensions and parameters |
The Workbench Selector is one of FreeCAD's defining features. Each workbench contains tools specialized for a particular task.
Most Important Workbenches
Sketcher
Used to create fully constrained 2D sketches.
Tools include:
- Lines
- Arcs
- Circles
- Splines
- Constraints
- Dimensions
Almost every mechanical model begins here.
Part Design
The primary workbench for solid modeling.
Typical workflow:
Assembly
Creates mechanical assemblies from multiple parts.
Examples:
- Gearboxes
- Machines
- Hinges
- Robots
TechDraw
Generates engineering drawings from 3D models.
Produces:
- Front views
- Side views
- Sections
- Dimensions
- Printable PDF drawings
Path (CAM)
Generates CNC toolpaths for:
- Milling
- Drilling
- Facing
- Profiling
Supports exporting G-code for CNC machines.
Parametric Modeling
The biggest advantage of FreeCAD is parametric design.
For example:
Later you can simply change:
The entire model updates automatically.
Typical Workflow
A common modeling process is:
- Create a new Body.
- Open Sketcher and draw a 2D profile.
- Fully constrain the sketch with dimensions.
- Pad (extrude) it into a solid.
- Add pockets, holes, fillets, and chamfers.
- Create technical drawings with TechDraw.
- Export to STL, STEP, or other formats.
File Formats
FreeCAD supports many common CAD formats, including:
- FCStd (native)
- STEP
- IGES
- STL
- OBJ
- DXF
- SVG
- IFC
- DAE
This makes it useful in mixed CAD workflows.
Typical Uses
| Industry | Example |
|---|
| Mechanical Engineering | Machine parts |
| Manufacturing | Fixtures |
| 3D Printing | Printable models |
| Architecture | Buildings |
| Robotics | Robot assemblies |
| Electronics | Enclosures |
| Furniture | Cabinets |
| CNC | Toolpaths |
Advantages
- Completely free and open source
- Runs on Linux, Windows, and macOS
- Parametric editing
- Python scripting support
- Large plugin ecosystem
- No subscription fees
- Excellent STEP compatibility
- Active community
Learning Curve
FreeCAD is powerful but has a steeper learning curve than some commercial CAD packages because it is organized around workbenches rather than a single unified interface. Once you understand which workbench is used for each stage of design, navigation becomes much more intuitive.
If you're using Gentoo Linux, I can also provide a 50-page illustrated FreeCAD beginner's guide with screenshots covering every step from installation through modeling a complete mechanical part.
