I am trying to create a wind sculpture and I could use some help. The sculpture will have 3 points of rotation all driven by the wind. Visualize the letter "Y" and you will have the basic idea. The base has bearings allowing rotation as do both of the arms. My prototype model works to some degree but stabilizes or "weather-vanes". It moves only when the wind direction changes. This is not what I wanted. What I wanted was for it to tumble randomly about. I am remembering my youth rocket building days. There I had to insure that the center of pressure was behind or lower on the rocket than the center of gravity or it would not fly straight. I'm wondering if making the center of gravity and the center of pressure the same spot on my wind sculpture will create the desired instability I'm after. I have no real aerodynamic or physics training/knowledge to speak of. So I'm going to need a laymen description if possible. Thank you for any direction or help you might be able to provide.