Control Coupling

[1bwana1]

Just finished and flew my YAK yesterday. In general i really like the plane. However, there seems to be a lot of control coupling in Knife edge. When I roll to knife edge with the canopy towards me the plane does a circle towards the wheels. I think knife edge circles are cool but I'd rather it was my choice to do it. I can make it fly straight with a lot inputs to the airlerons and elevator but don't feel I should have to. My other mid wing style planes do not show so much coupling. Does anyone else experience this? I guess I could mix it out but I'd rather not do it with the radio. Any tips on setting up the plane to address this issue?

Thanks, Steve

[paulg]

Your to nose heavy, and check your lateral balance. None of our planes have coupling, if it does than it's set-up of the plane, CG, Lateral balance, thrust etc

[Gary Hoorn]

Try some down-lines. What does the plane do then? As Paul suggested check your CG and move it to at least 3.5 inches. Doubtful if your incidence is wrong unless you made an error building. You can also try lowering each aileron 1/2 turn and see it that improves things.
Gary

[3DX Jim]

Yes, Paul is correct. Push that CG back and watch it flatten out real nice.

[JoeDirtRC]

My Yak isn't knife edging either. I roll 90 degrees right, then as soon as I give it left rudder the thing almost snap rolls back to the left. My CG was at 4 1/4" yesterday when I tried it. I was curious if it would knife edge better with the CG further forward. I'm going to try that and see what happens. I haven't checked my lateral balance either, so that may be contributing to the problem. Any other ideas?

[paulg]

Your plane is not laterally balanced that makes a BIG difference in how it flies. That will be the only cause for what you are describing.

[JoeDirtRC]

I will check that today. Thanks Paul

[JoeDirtRC]

That did make a big difference Paul. The plane was right wing heavy. I got it close to perfect, but probably not perfect. The plane did fly better. With the CG at 4 1/4" the aileron coupling was almost nothing, but the plane still had a good bit of elevator coupling toward the landing gear. With the CG forward at 3 1/2" it was almost perfect. It was hard to tell either way because of the variable winds that gusted from three different directions and was blowing the plane all over the place. Is this closer to how the plane should react?

[Mikey]

Make sure your thrust angle is set correctly also. On my yak I have 0 coupling. On the Edge I have a slight amount of roll coupling about 90 deg every four seconds that is nothing in my book. The Yak in zero wind will stay there all day with out any other inputs then top rudder.

[wings19]

What is the best way to check lateral balance on the Edge? Also, how do you laterally balance if it's already built? Do you cut a slit in the wingtip and add a weight?

[paulg]

hold the nose at the prop adapter and than pick the plane at the rudder, you will see one wing drop.

[wings19]

Ok and how to make it balance?

[king160woody]

I glued a penny on the end of my wing :)