How To Make A Surfboard Fin. Different types of foil will alter the way water flows over the surface of your fin. The flex that a surfboard fin has will directly relate to your projection into and out of turns, which in turn will produce speed and affect the control you have of the board.
If a fin has zero cant it’s position straight up and down at a right angle to your board. Sweep with guide rail, the airfoil, on the trailing edge as the path, and leading edge as guide rail. The depth of a fin is how tall, or how deep into the water the fin goes from the bottom of the board.
Sweep with guide rail, the airfoil, on the trailing edge as the path, and leading edge as guide rail.
This is going to be fast in a straight line, but it won’t give you as much responsiveness through turns. In surfing, you want enough lift—enough sideways force. If a fin has zero cant it’s position straight up and down at a right angle to your board. After some calculations, developed the base fin airfoil, with a top and (mirrored) bottom 4 point spline, with constraints to the handles.