these are pics of the lower chord i pre bent them in a jig i made from a chunk of red oak.i soked them in windex inside my high dollar stick soaked made from a 1 1/2 pvc about 40 inches long and capped the bottom and a screw cap on top .works great . the pland call for 2 1/8 by 3/8 stringers to make the chord and i didnt see this till i bent 3 1/8 by 1/4 stringers.oh well same idea different way of thinking. i used a micromiter to keep my spaceing between formers and spot glued them and checked them with a square.then spot glued the other two the same way.then put the clips on and layed the plane on its side and run my thin ca the length of the chord..