swift gull 35"

swift gull 35": a compact sailplane. the idea is to use parts already available and stretch the wing to make a sailplane-for soaring.
starting with parts for a mini-swift 24" http://hobbyking.com/hobbyking/store...dProduct=11306
plane: http://hobbyking.com/hobbyking/store...ider_PNF_.html
motor: http://hobbyking.com/hobbyking/store...or_1800kv.html
servos: https://www.hobbyking.com/hobbyking/s...cro_Servo.html
parts: https://www.hobbyking.com/hobbyking/s...0mm_Parts.html
esc: https://www.hobbyking.com/hobbyking/s...ontroller.html
pack: https://www.hobbyking.com/hobbyking/s...poly_Pack.html
prop: http://www.freakware.de/p/luftschrau...105-a66152.htm
i ordered 2 wings and used 1 for the center panels with constant chord and the other 1 for the tips. the reason for a gull wing dihedral is that, as the swift has the stab and the wing on the same line, the stab is in the wing's wake, and this means turbulence and consequently erratic response and unstability, so raising the center panels not only keeps the stab clear, but lowers the center of gravity and makes the plane more stable. and it worked as expected.
well, i had the chance to fly it and needed a lot of up elevator trim, so i checked the decalage and it was 0-0. meaning that there is no angular difference between wing and stab. no good. and it balances at 33%. so i decreased the stab incidence and tested it. this time it came with a lot of down elevator trim so this means i went too far so i went back to half of the amount and this time came out with no trim, so this is the right decalage. finally! i have learned that some times foam planes misbehave because the fuselage is bent during manuacturing and their tail incidence is changed. also reduced the rudder area a little bit (that i increased before) as it was overly sensitive. the motor i used is not powerful but it climbs at about 30 degrees. if i can find a motor that is more powerful, weighs the same and is same dimensions, i will try it. still i was surprised that, even if it takes 1 minute to climb, the pack lasts a long time, meaning it drains very little energy. it is fast, has a flat glide and handles wind well, and needs a good throw. but no tip stall nothing. all in all, with the exception of the decalage that i had to correct, it was a straightforward conversion to sailplane. but needs the german folding prop, that folds way better than the 1 that comes with the plane.