BULLSEYE

My Feedback: (3)

I am in the process of setting up my biplane and had a couple of questions.

Here they are:

1. I read a few posts saying that I should set my bottom wing incidence to 0 degrees and my top wing to -1.0 to -1.5 degrees. Does negative degree wing incidence mean that the leading edge is lower than the trailing edge?

2. I am trying to find the center of gravity for this biplane. I included a schematic picture of my biplane with the dimensions. I would like to have a safe starting point that is not tail heavy.

Thanks,

Bullseye

Rodney

Yes, negative means that the center of the leading edge is lower than the center of the trailing edge. I also agree that on most RC bipes, they fly best with the upper wing having less incidence than the lower wing. As to CG, it the wings are of equal area, start with the CG right at the leading edge of the lower wing. If the top wing has a lot more area than the lower one, the CG will need to be farther forward.

daveopam

My Feedback: (9)

For the CG draw a diagonal line from the main spar of the top wing to the main spar of the bottom wing. The center point of this line would be a good place to start. Once you find this point you can use either wing. I prefer to use the bottom wing with the plane inverted.

David

MinnFlyer

My Feedback: (4)

As for both questions, a lot will depend on exactly which kit you have.

SOME bipes fly better with negative in the top wing while others don't.

Ditto for CG. Are both wings straight? Are both swept? Is the bottom straight and the top swept? These will all affect where the CG should be

LesUyeda

From Lennon on Bipes. This has always worked for me.

Les