I have a Sundancer 60, high wing aerobat, with 72" wing. I am using a Futaba 9c radio. I want to couple the ailerons and rudder to to coordinated turns. What would be a good starting percentage for the rudder in the mix?

You are really better off NOT mixing the two. It might be nice for just flying around, but you'll have to turn it off to do any aerobatics.

That said, if you really want to do it, I would start with 5 or 10% and try it.

thanks Minn

About 10% but it's like Minn said. I have one plane I have it mixed into but it's just a big old Bipe I used to fly at IMAA events. I have been known to forget to turn it off but 10% is so little I never noticed it doing any stunts or landing. I got into the habit of using my rudder in turns so that mix is just one I never bother with anymore. It does work though!!

I used 10% and it seemed to work very well

I agree with Minn - I never couple my rudder with aileron. That's why there's a left stick! Seriously, I perfer to use my stick, instead of mixing. I think that I have a lot better feel for the plane using the stick as opposed to mixing, especially when doing aerobatics.

I understand not using a coupled rudder while doing aerobatics. This is a large scale looking plane, and I just want to use a coupled rudder while flying around and not during any aerobatics. I don know what the left stick is for, but why have a computer radio if you don't use the mixing. That's like having an automatic transmission and still shifting the car!

The ironic thing is that you'll never know how much you need to mix in until you start flying it in using your left hand.
Then, with the aircraft on the ground, at your feet and tranny in hand, you'll kinda go... OK I tend to use this much aileron (move stick and make mental note of aileron deflection) and this much rudder (move stick and mack mental note of rudder deflection) when I doing an average turn. Then just mix in rudder so it corrisponds.
That's the way. Every aircraft is different so it's pointless giving you some percentages.
Believe me, the best way, the only way really... is to fly in it using your left hand. Flying without using rudder is very silly[]. Once you've discovered it's presence, EVERY aspect of your flying will improve imeasurably. From straight and level flight, to cross wind controll, to all aerobatics... to take off and landing. You name it.
The cool thing is... it's fun to learn.
Enjoy.

It's called, "Flying" not, "Letting a computer fly the plane for you"

Mixing is great for things like, "V" tails, Elevons, etc. but you don't always want right rudder when you input right aileron and vice versa.

You know what guys, I've been flying for almost 30 years and all I did was ask a simple question just to get a starting point for the mix and now it has turned into a bash session. What gives? All I wanted was a starting point and Minn answered the question out of the gate and I thanked him for it. That is a clue that I was satisfied by his answer. All I wanted was a starting point and then use the trial and error method to tweak that setting. As I posted this question, I knew I would regret asking it. I quit coming to RCU because every question anybody asks normally turns into a bash fest. Thanks to those that gave me the simple answer I was looking for. I will start at 10% mix and tweak it from there. And by the way Minn, I do fly my planes, not the radio. Am I to assume that you never use any mixes or don't have a computer radio?

Sorry, I didn't mean it as a bash - although looking back at it, I see how it could have been misinterpreted.

mscic - I did not mean my answer to be a bashing. I just never couple the rudder to the aileron. I do use many features on my computer radio, but many I just do manually. Maybe it was the way that I was taught before computer radios were common, use that left stick to help out in the turns. Even the full scale that I've flown, rudder input is never the same on every turn. I have flown many planes (that belonged to other pilots) with a coupled rudder (usually 10 -15%), but I personally do not like it. I didn't like the "feel" that was input when making turns, especially in windy conditions. I know that when ever I set up a plane on my radio, I make sure that the coupling is not engaged. But this a personal choice, not one that I encourage others not to use if their radio can perform it.

Coupling the rudder to the ailerons by about 10% is very commonly used by many people

And you will see me ranting about people telling other people to do things like use a Y harness with your nice new 10 ch computer radio so you can keep things simple. Why bother buying a nice radio, fly with a four channel if you want to keep it simple!! Play with the mixes, that's why you spent the big money!!![:@]