The entrance to the Commons is at Washington and 3rd Street. I'm telling you this so you don't confuse yourself with Google Maps and drag your friends through the rain looking for this place (it's NOT the Commons Mall, which appears to just be a Sears).
If you time your visit right, you may get to see more action than the usual three or four whirring, spinning parts (still cool). Apparently the large metal balls drop between noon and 1 and 5 and 6 p.m.
Chaos I is one of two Tinguely installations in the United States. The other is Cascade in the Carillion Building in Charlotte, North Carolina. After I watching this video, I will surely take a field trip to see this if I ever have an extended layover in Charlotte. Hopefully a cab driver can get me there better than Google Maps.