I tried using a piece of fence as a drag if you pile a bunch of. fine dirt on it. It works good to fill in small holes. But it develops a Long Wave as you go down the runway. The problem is the cyclone fence has no cutting edge I added a heavy pipe to the leading edge and a steel catwalk grating to the back, longer waves. The drag has to be rigid and heavy so it shaves off the tops of the humps I like the idea of the truck frame with I beams welded across at different angles. The each angle cuts the hump in a different direction. Only problem being do you have enough Horse Power to pull it. One fellow I talked to built a drake wider than his tractor and about half as long with about five cutters set at different angles. This was mounted to the tractor s 3point hitch so with the draft control he could apply as much or little pressure as he wanted. It also could be lifted for manovering and transporting. I never saw this but he said it did an excellent job of making a large area flat.