FreeCAD – some experiences

FreeCAD-logoI was looking for a 3D CAD program for OS X for a limited budget. After looking into some demo versions of commercial programs and some open source programs I decided to look into FreeCAD.

Let’s start with the good things: The parametric modeller has a steep learning curve. But when you finally understood how everything works it is extremely powerful.

Another big advantage of FreeCAD is its availability on Linux, Windows and OS X. There are only a few other CAD programs that are also available on these platforms.

If you’re not a designer, but a programmer, you will like the scripting interface. You can create, modify objects using Python. If you have experience with some programming language, it is easy to learn the Python basics needed to control FreeCAD.

Unfortunately FreeCAD has also some disadvantages:

The CAD kernel that is used is OpenCascade. Unfortunately this kernel still has some bugs. Some functions work not as expected, some will even crash the program. After filing a bug report for a specific problem, the FreeCAD team answered: “this is a bug of the underlying CAD kernel, we cannot fix it”. This can be a big risk for large design, because you never know when you will find a bug that is critical for your design.

The other big problem is speed. The whole application runs single threaded and working with models that consists of more than a few blocks can be extremely slow. I created a 3 dimensional logarithmic spiral that consists of about 500 objects. The calculations are simple, but the program stills runs more than a minute on my PC.

Conclusion: If you’re a programmer or you work with simple 3D models, FreeCAD might be a program to look into. If you work with complex models, the speed and the bugs can be serious disadvantages.

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