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"Keep calm and carry on." - Winston Churchill
Topology
FreeCAD
It all started some two decades ago. I discovered Blender, it was only 4Mb then, but I was amazed at what this free, opensource, program could do. I figured that if Blender was so good, other opensource programs must be worth looking at... which proved to be the case.
FreeCAD is the latest opensource program which I have been learning to use.
However there is a major problem with the official version of FreeCAD known as the Topological Naming Problem.
It works like this. Lets say I draw a square and then I extrude/pad it into a cube. It has 6 sides which are named Face1 to Face6.
Now I draw a square on one face and pocket a slot through the cube, this adds 4 extra faces.
Now I go back to the original sketch and draw another square in the original square, expecting that the already applied pad will turn this square in a square to a slot in a cube to add to the already existing slot... except this doesn't happen. The square in a square moves or disappears. FreeCAD appears confused because it has shuffled the face names around.
It is said that other CAD programs do not suffer this Topological Naming Problem at least to this degree. It might also be argued that the Topological Naming Problem makes something of a mockery of FreeCAD being a parametric modeller.
However all this is mere whinging. I say this is a 'major' problem but there are workarounds, such as using datum planes linked to the co-ordinate system, which is arguably a more robust way of making a model in the first place. Also one could simply use the FreeCAD Link Branch version which seems to largely overcome the Topological Naming Problem.
FreeCAD Link Branch
This version of FreeCAD is the one I currently use. It is a fork of the official FreeCAD which appears to solve the Topological Naming Problem. It is based on FreeCAD 0.19, whereas the official FreeCAD is at 0.21 so FreeCAD Link Branch will be missing some features of the latest version of the official FreeCAD. I'm not advanced enough to miss those features so it doesn't really affect me...
If you click on the picture at the start of this page it will take you to a quick comparison of the Topological Naming Problem in the two FreeCAD versions.
7th April 2024