Here's a detail picture of the hardware... this is the "live" or moving end of the bi-fold door. The stationary end has the same design just without the linear bearing, you can see that and the gimmick at work in the video I've linked here...
http://www.youtube.com/watch?v=22pnY9Z-gJMUnfortunately, I did not video the machining of the door... but I did snap a pic at the end. Also, I've included 2 screenshots from when I was doing the design. Fun stuff that I will be doing more of for sure!!