Here is a small manual which details step by step a way of designing a traction foil using a CAD tool. Obviously, you'll need a few things to get started : a computer, patience, a CAD tool (AutoCAD, Amapi 3D for example). I'm currently using Rhino 3D. An evaluation version is available on their web sitewww.rhino3D.com. In the following pages, I'll assume you know how to use a CAD program. Some of the functions may not be available with some CAD tools. It may exist some workarounds for some functions, but a few are mandatory. For example, if you wand to build the designed foil, be sure to have an unrolling function available (I'm not sure AutoCAD has).
Little warning : designing your own traction foil will give you a lot of satisfaction if it flies well, because it will be your very own. When it flies. Using a CAD tool is not a guaranty of success. Before starting, you'll need to ask yourself a lot of question, and know a little about foil design. If you're not sure and don't want to waste money, use Foilmaker and a proved design. You'll be warned.
Let's go ! I suggest you make a copy of your file at each stage of the process. I usually number my files foilXXX.nnn.extension, nnn beeing increased at each stage. This way, I can go back to an earlier version if things are turning bad.
Profile
Shape
Twist
Canopy curve
Surfaces
Details
Bridle
Surfaces unrolling