I made this mobile with used tea bags and paper. The design allows the bird to move swiftly under the shape above it which represents the infinite.
You may also want to have a look at the link below. I had a book of Calder's extraordinarily creative mobiles when I was a child. His ludic work was a wonderful revelation in my younger years and 'Cirque Calder' one of my favorites!
http://www.calder.org/
