Nice idea where the author doubled up the chains so that one side could be driven with a gear, and the other side have bolted tracks on it. The downside, you have to break each ligament in the chain and put bolts thru them all. That could be very time consuming. The author “bought” all of his materials, but I am sure most of the stuff you could pull from the junk bins.
http://hackaday.com/2015/05/06/diy-tank-tracks-give-tons-of-traction/