Ever managed to break or lose your roller blind cord connectors? I have, many times, so that's why I designed this one using OpenSCAD. Now you can just make your own!
For more information about the development of this design please visit: http://3DPrintHQ.com/smallest-designed-thingiverse
I designed this thing using OpenSCAD. I've included the source file so feel free to modify it yourself if it doesn't quite meet your requirements. 3D print two of these and clip them together. They usually hold quite well but a spot of glue wouldn't go amiss. I'd use a raft too while printing as the contact area with the build plate is quite small and it may slip or tip over otherwise.