Ok i usually buy arf planes or build planes from a kit thats been manufactured, but this time i found a plane a guy scratch built and it looks beautiful ! anyway its about a 30-33% extra 260 wing span is 92'' fuselage is 81'' with nothing but airframe it weighs about 18 1/2-19 1/2 pounds, I'm putting a 3w-75 in it which is brand new. My question here is how I'm i supposed to know how to balance this plane? where would I balance it? upside down, right side up?if i could just get it close to where i know it want act fool on madien i would be very happy, any help here would be great and thanks for the time.



PS where can i buy custom aluminum wing tubes, has to be 5 foot long at least thanks

Measure the root of the wing, and go back about 25%-30%. That will give you a good starting range. Balance it upright and keep the throws reasonable and you should be fine. As long as the CG is forward of the thickest part of the wing, the plane should be stable.