Flaps Geometry Test
My first question looking at the Flap design was "Why is there a difference in the pivot point at the root vs. the wing tip end of the flaps?" I couldn't wrap my head into it so I decided to make a prototype out of cardboard and hinge music wire. I kept the tip pivot at 11/16" and made two holes at the root, 1 1/16" and 11/16" set back from the leading edge. The distance from the bottom was 5/16" on both sides.
Well the answer maybe obvious to some, but I determined that the pivot points on the plans account for the wing's taper and change in radii. The pics show the results. If not hinged offset at the root, the lowering of the flaps won't stay parallel to the top of the wing's trailing edge This let me start the build. The flaps won't be exactly scale like but it will use the hardware given, a large nylon L shaped bracket. Other forum comments suggested adding a third hinge rather than pivot at only two points. I figured out a way to do this.