Very impressive, a really neat project.I was going to share that CG picture this morning. The ballast ratio is 70 percent which is what gave it that stability. The wing structure was designed in 3D and the sections were taken using the Orca section command and then lightening and alignment holes were drawn in Acad. The wing uses 42 total basswood laser cut frames and 5 meters of 2mm diameter paltruded CF rods and one 88 cm length of 7mm od 6mm id carbon tubing for the mast. The total wing height is 1.25 meters and all the structure weighed only 75 grams, which is lighter than some of the masts used in the rest of the fleet. When I did the weight study the CG came out as 22 cm below the DWL. Ironically enough, because of this my light air boat actually reaches her sweet spot above her designed maximum wind speed.
For the skin I used saran wrap from Poundland which cost £1. Then I shrunk it using the radiator in my room to get a tight smooth finish and coated it in parcel tape which also cost £1. I found it quite amusing that my instructors couldn't believe that was what I used for the skin!
I added some pictures of the wing construction below. It took me 5 days to glue together and 2 to put the skin on. As a side note, you can see in one of the pictures my first attempt to put a skin on. It turns out the technique from a popsicle stick boat I built 2 years ago worked better than the more advanced shrink wrap I bought specifically for the job in this project.
I built the wing in 4 pieces to make it easier to build and then assembled the four pieces together in the final stage. The top 37 cm was designed in 3D to telescopically connect with the bottom 88 cm so it can be reefed.
The bottom picture is of my friend Harris and I putting the rig on. It was blowing hard and I needed some help to keep it from flying off while tying the stays down tight.