I uploaded another video with more light so you can see the machine better. 
http://www.youtube.com/watch?v=3R56UBlQ6qs

Watch where the two inner ring connect - the slider on the left would move in a circlular motion just in the back left area, and the right slider would need to move in a circular motion in the front right area. 

I'm still trying groupings, but it hasn't worked out yet.