1800mm wing for FT Explorer

For this year's science fair, my school is doing this thing called the "engineering challenge" where you design a solution to a problem and test it. I chose to improve the flight time of an FT explorer by designing a new, larger wing for it. I set a goal to improve the flight time by at leat 1.5 minutes from the original FT Explorer wing. I did this mainly by making a larger wing, but I also tapered the trailing edge of the wing and added wing fins. For more information on the scientific aspects of the project, look at the written report in the Google Drive folder linked at the end of this article. In the end, I actually increased the flight time by 4 minutes on average. The stock wing flight time was 22 min 13 sec, and with the new wing was 26 min 13 sec. The grade I got on the project was an 100 and I won first place in the science fair. 

The assembly of the aircraft is similar to the original FT explorer wing, but there are a few changes. On the plans, blue is tile edges, red is a score cut, and black is cut through. Once the plans are cut out, lay them so the score cuts are facing down, and tape them together like the original FT Explorer wing, but with 3 sections. Then do a double bevel in the middle of the wing and a single bevel on the control surfaces. On the 33 cm wing spar, remove the foam in between the score cuts. Then fold them over and glue them together. Also, cut a paint stick to 13 cm. This is supposed to make the wing more rigid where the pieces come together. Then glue the bottom layer of wing spars on in this order:

It doesn't have to be done exactly like this, and the wing spars are one of the weakest design points of the model. On the top layer of wing spars, glue the 38 cm spar on top of the paint stick and the 13 cm spar, leaving a space for the servo hole. In between the 38 cm spars, glue the 25 cm spar. The servos I used needed extensions, and I just did the lazy thing, which was mounting the wire on the bottom of the wing. If you want it to look better, route the wires through the wing, but you will need longer extensions. if you are mounting the servo wire on the outside of the wing, you can wait until the rest of the wing is finished. When the airfoil is established, the edges of the wing need more pressure so they don't pop up. If you want to put the winglets on, remove the foam in between the score cuts. It is more tail heavy with the larger wing, so be sure to be careful when testing. 

This is the first airplane part I have designed, so any comments/feedback is welcomed. Please make changes to the plans if you want to. I included the .dwg files in the Google Drive folder linked below.  

Link to the Google Drive folder with .dwg files, full results, and the final report: https://drive.google.com/drive/folders/0B3v7aGIhpoJhS3VyQ0cxUHl6SzA?resourcekey=0-RgV69AKrJ7whfBbKyJd-xg&usp=sharing 

Plans: All PDF tiled plans