Hey guys

I just got my 7CAP this week and i set it all up and went to fly today..
i got out at about 5:45 this morning so i wouldnt have to deal with the wind
anyways i set up dual rates on ailerons...elevator and the rudder..
a little but of expo so i would screw things up too bad

ok so i set it up just fine..and let me tell you this was the first time i did it and i feel like im a pro at it..
anyways

I was trying to do a knife edge and i realized something was wrong.
everytime i used my rudder my plane would not only turn but rotate as well..
i couldnt correct this with ailerons or anything
anyone ever have this happen to them or what else should i mix in ??

Thanks..
Felix

What kind of plane are you flying?

Also not to clear what you mean. Are you saying that when you knife edge the plane turns in that direction? does it roll over to the side you are giving command to?

Some planes can do a knife edge with very little or some cases no corrections. But depending on type of plane say a trainer with lots of dihedral it takes a good bit of correction.

its a Great PLanes Easy Sport..

it did the knofe edge better without the dual rates...before i set it up..
Felix

I am not sure how the dual rates could of made it worse. Did you switch to high and low to see how it reacted? I know to little will make a good bit of change on how it acts or is able to hold position. That may be a problem.

On the other hand to much expo could make it feel different also. Since in first post you mentioned you added expo also. It could be to mushy in middle to where before it was linear. Maybe you had more responce out of less stick than with to much expo.

I would think you would need very little expo in that type of plane. I would start off dialing in expo at a very low %. Then if it is to touchy add more until you find a good spot for you to keep it at. Now in some cases it is other way around.

Also did you program expo on both high and low rates or just on one rate?

I have a suggestion to make, and it applies not only to radio setup but to any setup changes you make with your airplane.


CHANGE ONE THING AT A TIME! Unless it's a safety of flight issue.

That way, you can see what result came directly from that change, instead of having to guess. Setup dual rates, fly airplane and make sure trim is good, D/R is what you want, etc etc, then land and fool with expo. Takes a little longer, true, but is a more sure method of doing a setup.

Andy

Many planes will roll or pitch with rudder in knife edge. (pitch and roll coupling)

The amount of rudder you apply to hold the knife edge affects how much pitch and roll effect you get.

And how much airspeed and how you have the fuse angled as you roll to knife edge will affect how much rudder you wind up trying to apply.

How vertical your knife edge affects things as well. I used to "cheat" my knife edges a bit on my Cap by rulling a bit past vertical, it looked good, and reduced some of the coupling.

So, first thing to do is to get as consistant as you can at entering knife edge. If you can't roll in consistantly, you'll drive yourself nuts trying to hold it.

With work, you can just hold in the approprate amount of rudder and aileron to keep the plane going straight. My Cap would roll with rudder and pitch towards the gear. I had to hold rudder, opposite aileron, and up elevator in knife edge. Took some doing, but keep working at it, you'll get better at it.

You can also mess with mixing on your radio. But until you can roll in to knife edge consistantly, it will be hard to figure out what the plane needs. Then go up high, roll to knife edge one way, and hit rudder only, and go hands-off on aileron and elevator. See what it does. Now, repeat, rolling the other way. From that, you can determine what mixes to set up to straighten the plane out a bit. Personally, I find the rudder->aileron mix to get rid of the roll coupling more useful, the pitch coupling I can handle on my own easily.

As a silly thing, you didn't accidentally turn on some kind of mix while setting up the rates, did you? On the ground, check your plane at high and low rates, move the rudder alone and see if anything else moves. Just a thought.