I’ve recently got back into photography and one thing that was really annoying me was the packaging that filters are shipped in – it simply doesn’t make a decent case for storing the filter when not in use, so I set about designing something nicer in LibreCAD. Once I had a working design it occurred to me that editing it for each filter size I wanted was going to be a real pain, so I decided to investigate OpenSCAD.
Unlike “ordinary” CAD software OpenSCAD is basically a programming language. You can script the design of your object using basic primatives to lay it out combined with functions like union and difference to blend them together and chop bits out. Because its a scripting language you can also use variables to define parts of your design, so for example in this project I can set the filter size I want to store, and the size of screws I want to use to fix it all together, this results in an output DXF file just like my original from LibreCAD, but customised with the options I selected. Its a lot more work to start with, but I can now generate cases of any size in seconds.
The OpenSCAD source file for these can be obtained from thingiverse.
Havent used OpenSCAD before, I’ll give it a go. Another piece of great free CAD software is FreeCAD (http://www.freecadweb.org/). It has a nice GUI & also has a Python API (2.6 if I’m not mistaken) which means you can not only parametrize your designs but you can use Python libraries like Numpy & SciPy which can make geometrical modelling alot easier. I think its also possible to access the FreeCAD libraries outside of the main application but I havent tried it.