Cool!
And you can animate it by Sketchyphysic2 ;)
http://code.google.com/p/sketchyphysics2/

Hi Frenchy
I have made some animation using the traditional instruments of Sketch-Up, thanks
to have suggested to me that they exist some of new, think added in these last times
The truth is that I have a little neglected Sketch-Up, lately
Many Thanks Frenchy
al