Need some help on a project

[Rebellion2638]

I have a project that I am working on and there is something that I need that I can't find anywhere (a file or help on making a part).

What I need is to be able to make or acquire the file for a retractable USB cable. I am mainly looking for some help on how to make one, but I would be just as happy for the file itself so I can understand what I would need to do to make my own. A tutorial or instructions on how to make it, alongside the cad file would be the best of both worlds.

I am using Autodesk Inventor 2014, but I posted it here in this section because I don't need it to be Autodesk exclusive and I want more people to be able to see this post.