Today I began forming the longeron curves. I brought the template with me to work yesterday, glued it to a piece of alu sheet, and cut along the line. This sheet will work as a guide when forming the curves.
It went a lot easier than I had anticipated. I made marks at every ½ inch, then I clamped the longeron in the vise, and began forming. It is done by pulling the free end to establish a small pre-load, then giving it a whack with a rubber or fiber hammer. Then you move the longeron to the next mark and repeat. I found the best way was to check with the guide every 2 inches or so, and readjusting as necessary to get a perfect fit, before continuing. As you form the horizontal curve, the longeron will tend to bend down as well. This is corrected by rotating the longeron 90° in the vise, then straightening by hand using a steel ruler as guide.
First longeron finished, with the guide clamped in place…
Both longerons finished and clamped together. I am quite pleased with the result!! 🙂