Tool for sweeping bends in square tubing.
Talk about crude tools...this is the one I used for bending the ribs for the body of my roadster. The tool consists of a "form", 3/4" particle board cut to the inside shape I want the ribs. The form is then bolted to the side of the garage and a length of 1x1 tubing is then clamped to the top of the form. a come-a-long is then attached to the other end of the tubing and secured with a bolt to a garage stud. Then just crank.
Here's a shot of the "tool", a bunch of ribs that I bent with it, and a shot of how these ribs were used to form the rear section of my '31 roadster body. More info on the bending process can be seen here.