rcbob51

Can anyone tell me who makes or made this Bi Plane? I am trying to find out where the C.G. is located.
Thanks for your help
Bob

jetmech05

Its not Aeroworks...could it be a recovered Great Planes?

rcbob51

Not an aeroworks plane. It has a fiberglass fuse.

LesUyeda

CG is not manufacturer specific, it is airframe specific.

This should work for all Biplanes.

Les

stevegauth30

I know its certainly not a very accurate way to balance a plane and alot of people will probably get mad at it but i usualy always balance a bipe at 1/3 of the top wing chord with the plane upright and it always flies great. Its just a suggestion that works for me. Take it as you will and good luck. Looks like a nice plane.

countilaw

This may help you find the CG of each wing, then use the difference between the top and bottom wing. This will give you a starting point for the first flight. Then you can adjust from their for the second flight.

http://www.geistware.com/rcmodeling/cg_calc.htm#cg


Frank

vertical grimmace

My Feedback: (1)

That sweep is going to give you a more aft CG than what that diagram would calculate.

dbacque

My Feedback: (3)

Can't be sure from the pictures but it looks like the top wing is swept and the bottom wing straight. LesUyeda's drawing is correct for straight wings and a bit on the conservative side (not a bad thing) at 23% MAC. For two swept wings or one swept and one straight, do the measuring and the balancing at the wing mid-point. So use the stagger and chords at wing mid-point (half way from center to wing tip) for this calculation and then balance at the wing mid point.

Oh, are the wings close to the same span? For wing mid-point, probably split the difference between the top and bottom wingspans. At 23% or even 25% MAC you'll get a conservative (safe!) answer, then trim for flight preferences.

Dave

LesUyeda

"LesUyeda's drawing is correct for straight wings "

MAC is MAC. it is just determined differently between swept and straight wings.

Les

buzzard bait

It is correct for an airplane that needs its CG at 23% of the MAC, and that is all. Where did the 23% come from? From the wing area, the stab area, the tail arm and the MAC. It will likely be very safe for your plane because most planes can be safely balanced further back than that, but it depends on those four factors. The only trouble with doing it that way is that you may go to some trouble to get the CG that far forward and then find out in flight testing that it is unnecessary. That's why I like to do the calculations. Jim