need,wing cg ronnies
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RE: need,wing cg ronnies
It depends on the size of the stab and the moment arm but if they are fairly normal I'd start with the balance back at the 3 inch point back from the leading edge at the root. It'll probably be too far forward still at that point but you can fine tune it from there. Certainly better than too far back.
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RE: need,wing cg ronnies
Note... the CG does depend on the rest of the aircraft configuration somewhat.
If its a conventional type.. Engine in front, then main wing then the tail surfaces back a bit behind the main wing... the above is correct. (unless the Stab is very small or very close to the main wing... then act like its a flying wing.)
If its a flying wing, you need to move the CG forward at least 1.25 inch.
If its a Canard... we need to know the Canard (the little wing in front) size and how far between the wings. (CG could be forward of the main wing with a Canard.)
If its a conventional type.. Engine in front, then main wing then the tail surfaces back a bit behind the main wing... the above is correct. (unless the Stab is very small or very close to the main wing... then act like its a flying wing.)
If its a flying wing, you need to move the CG forward at least 1.25 inch.
If its a Canard... we need to know the Canard (the little wing in front) size and how far between the wings. (CG could be forward of the main wing with a Canard.)
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RE: need,wing cg ronnies
Oh great. You drew it backwards. In drawing wings like your sketch it's generally accepted that the upper side is the leading edge.
This changes everything. The balance point in this case should be about 2.25 inches back from the leading edge.
This changes everything. The balance point in this case should be about 2.25 inches back from the leading edge.
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RE: need,wing cg ronnies
Thanks again BMatthews RE: need,wing cg ronnies (in reply to CafeenMan) .sorry about the inverted picture as you can see the only hint is that I drew in the ailerons, Its a good thing I didnt mount the wing yet.so Ill make the CG at 2.25 inches from the front edge going back.
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RE: need,wing cg ronnies
Ronnies - I thought you had asked how to find the area. My response was to divide the wing into triangles and then do the math. I don't know why I thought you asked that. I must be getting old.
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RE: need,wing cg ronnies
Ill bet Im older than you at age 56, I wouldnt know the triangle math just basic, but Im glad you helped me anyway.Thanks Ronnie
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RE: need,wing cg ronnies
ORIGINAL: Ronnies
Ill bet Im older than you at age 56, I wouldnt know the triangle math just basic, but Im glad you helped me anyway.Thanks Ronnie
Ill bet Im older than you at age 56, I wouldnt know the triangle math just basic, but Im glad you helped me anyway.Thanks Ronnie
Area of a triangle is 1/2 x base x height. So if the triangle is 6" on one side and 18" on the other, then 1/2 x 6 x 18 = 54 square inches.