I've got my trainer now for almost 2 months and still haven't flown it yet !!! (Caus I never got time to go to the club, since you're only allowed to fly there in weekends. ... ... Stupid regulations here in Belgium, I'm not even allowed to fly on a non-certified field !!!)

Anyway, this weekend on the other hand, I will have time to go to the club and take my first step in RC flyin However, ever since I build my (ARF) plane, there was something wrong with the ailerons. (If only it would use 2 servo's instead of one and direct control.) The problem is that the ailerons don't got an even throw (don't know if this is the right word)


Here are some pics to clearefy everything: (don't mind the messy room)


1) Pushing the aileron stick all the way to the left: (left wing of the plane)



2) Pushing the aileron stick all the way to the left: (right wing of the plane)



3) Pushing the aileron stick all the way to the right: (left wing of the plane)



4) Pushing the aileron stick all the way to the right: (right wing of the plane)





In other words: this is how the throw of both ailerons looks like:

1) left wing



2) right wing





So, as you can see, both the ailerons move the same when going up, but the aileron on the right wing moves much more down then the one on the left wing !!! Will this be a problem, aside from the fact that my plane will roll left much faster ?

Also, is this enough throw for the ailerons ?



thx,
Prophex

(Damn I hope I used the word throw good, caus I seem to have used it alot. lol)

Wow, nice graphics! I'll throw these ideas out for discussion.

First, it's a trainer, so getting these things perfect is not required. However, it's great that you are looking at them, because this kind of adjustment will be important if you want predictable aerobatics.

I suspect the reason you have different amounts of throw is that the aileron control arms are different lengths. When you are setting up ailerons the first thing to do is make sure the servo arm is centered. You also want to start with the attachment point on the aileron control arm to be the same height from the centerline of the aileron. Adjust the length of the aileron control rods so that each aileron is centered when the servo is centered. If one of the ailerons has more movement than the other you need to either increase the one that has too little, or decrease the one with too much. You adjust the amount of throw by changing the length of the aileron control arm. Making the arm shorter will give more throw, making it longer will give less throw. I'll see if I can draw up a little graphic before Minn beats me to it.

It would be ok if they were going up more than down.

In your pics, we can see that they are different, but what I would rather see is a pick of the wing removed, showing the servo and torque rods at level, full right and full left

Could you post that?

Your whish is my command (for now)

I guess piper_chuck was right, the servo arms aren't te same length and the servo is also not centered (I'll explain why later):

1) Centered:



2) Centered:



3) pushing aileron stick to the left:



4) pushing aileron stick to the right:





The problem was that when I got the "kit" (it was an ARF), the connections between the servo-arms and the ailerons were not construced good. There was a big difference between them, so I had to bend one of them to the same position as the other. But in time te connection went back to their original position. [&:] (kinda hard to explain)


anyway, what should I do now ?

All of my comments refer to pictures of wing off plane. In picture #1 the ail servo is not quite centered. Turn on radios and connect ail servo to rec. make sure ail trim is also centered. At this point you need to make the control arms perpendicular to the servo, not almost. May require removing pivot screw and pulling arm of and repositioning it and re installing. May even need to turn it 90-180 or 270 degrees to get best alignment due to way these are made(refer to manual for explanation). The ends of your ail torque rods should be even. If not even, you will NEVER be able to completely balance the THROWS (yes, correct word). It read like you said you re-bent the ail torque rods for some reason. Is this correct and if so, WHY? This will be difficult to fix without removing the ailerons. The control rods SHOULD come up being very close in length, the difference making up for small mfg tolerances and later on - trim of a/c. What type of plane (mfg & model) is it?

Minn- your turn

Yes, as Bruce said, turn on radio and center the trim.

Next, I would discard the 4 point servo arm you are using to a 6 point arm.

Place it on the servo. If the arms don't line up properly, rotate them to the next position. eventually, they will line up (If not perfectly, at least they will be very close. (You can see that on yours, angle "A" should be straight across)

Next, you need to bend the torque rods so that they are even with each other, not angled like "B" in the picture.

Then, connect the pushrods to the two servo arms that are away from the ailerons (The two pointed out for "Top Wings" in the picture)

It seems to me, you may have the same problem I had. The cut-out slot in the wings (which the ailerons rods travel back and forth in) are improperly cut. On my alpha, I had to use the dremel tool and complete the slots in both directions on both wings. Be careful, not to take out to much, or go through the wing.

But, smaller amounts of movement is better when learning to fly, makes the planes controls softer. Not so radical.

bbell

The reason MinnFlyer had you connecting to the 6 arm servo that way is to give you "differential ailerons". The purpose is to give more "up" travel than "down" travel. This reduces the drag induced by the lowered aileron compared to the raised aileron. In turn, this reduces a condition known as "adverse yaw" which is why you need to add rudder to make a coordinated (smooth) turn. This condition is especially relevant in full scale a/c where they even design the aileron itself to assist in the differential.

Bruce[

Perhaps Im stating the obvious but just in case it was omitted I will mention that I think you should have the servo hooked up and Tx/Rx powered on and trim set at neutral when installing the servo arm. If you dont have the power on, the servo may not actually be at it neutral position which is where you want it when you install the servo arm. I dont want to mess up Minns excellent information here. Personally I do all of my hooking up and adjusting with the system powered on. The only thing I MIGHT turn off for is to tighten a servo screw so I dont strip a gear.. anyways I quitely bow back out if Im out of line..


Also Minn,

Is the reason his aileron "torque" arms arent even because they were glued to the ailerons at different angles? If so when you bend one wont you distort the height of the control arm a little? I think under the circumstances he has no choice but to bend it but Im just checking to see if its just me or it was originally glued in a little out of line?

Minnflyer - Bending the torque rods... that is something that I have always been very hesitant to do because I am afraid that the hole in the aileron (or elevator or whatever) is just getting bigger and that the rod itself isn't really twisting. So at the end, you have a loose connection to the rudder (ie. there is some play in there). Is it smart to bend torque rods while installed? Won't the soft balsa aileron around the torque rod just compress?

prophex - as someone already mentioned, on large problem is the openings for the torque rods are too small. Open them up a bit to ease the travel. First, disconnect the push rods. Now you can either use the travel of the rods themselves to crush the balsa around them to that you get a good amount of travel or you can do as bbellfish said and cut or dremel it larger. I do the crushing thing and it works fine. Just use your hands on the control arm (not on the aileron) to deflect the ailerons beyond the recommended throw.

That should help you get around the same throws. Then just center the servo arm as minnflyer suggested. Also, the height of the horns of the torque rod should also be the same height.

I wouldn't deal too much with the torque rods since it's a trainer... good luck!

That's what happened the first time. But I immediatly stopped bending and just took the aileron of again and then used a wrench to hold back the torque rods. But the weird thing is, I got them even once, but now it seems like the torque rods, in time, automatically bend back to their original size.


LoL, a guy from my hobby club came to have a look at my plane when I finished it and I showed him the aileron problem. He said that ailerons should move down more then up. Guess he was wrong !!!


I already dremeled out a bit. Caus I to had that problem. One of the ailerons couldn't move as freely as the other one.




One last question: Do you need much throw on the ailerons on a trainer ?

thx for all the replies,
Prophex

BigNed-
If you read Post #5 of this thread you will see that I had him turn the radios on and center things up.

Bruce

the recommended throws are usually enough for a trainer. they should already be on the conservative side. if you've dremeled it out already, have you solved your problems? a new picture of the dremel work would be good.

Do you hear buzzing sounds when you stop at the most left or right movement?

Whatever,

[link=http://www.rcuniverse.com/forum/You_will_crash_%21%21%21/m_2668764/tm.htm]this[/link] is what happened because of the ailerons.

If this can help...

"Servo: importance of correct setting + graphic calculator"

http://www.rcuniverse.com/forum/m_18...tm.htm#2363426

Philippe
Brussels Belgium

Not sure, may be posted in other thread,,,,

did you go ahead and fly the plane without fixing it?

He did not mention fixing them there or here. I was unable to open the video there on my computer.