I just finished my Ultra Stick 40. I'm not sure I dare fly it because when I test the aerlerons, regardless of which way I "turn" whichever aerleron is up has more throw than the one that is down. Is this a problem? How can I make them match?

what you have is aileron differential which is desirable on a flat bottom airfoil and will not cause any real problems on a chambered airfoil.if you have a computer radio you can fix it with programming.if not you can do it mechanically on the servo wheel.move the linkages from the 9 and 3 o'clock position to the 8 and 4 o'clock position

Remove your control arms from the servo. Turn on the plane and transmitter and nutralize aileron trim. install the servo arms so the arm and the control rod make a 90 degree angle. readjust the clevise at the contol horn on the aileron so that the aileron is nutral. If you do not have a clevise on the aileron control horn and have a Z bend adjust where aplicable. if it is not adjustable replace the setup with adjustable control rods. Recheck for aileron differential.

My radio is JR 6102. Do I adjust the throw, the sub-trim or what? I've tried several things but I really don't know what I'm doing.

I made sure of all of this setup when i finished the plane--everything was at neutral. So now what?

It sounds as though the control horns on the ailerons are not lined up properly with the hinge line of the aileron/wing and also your control horns on the servos may not be set in the same place.

Not amount of radio mixing with correct this as you will change the full rate throws as well as the neutral points.

In all your geometry is not correct

On the radio, get all your sub-trims back to zero percent, get the flaperons settings (aileron/flap) percentages back to 100% and center any aileron trim you may have in it.

Now turn the plane and TX on and wait for the aileron sevos to center. Make sure the servo arms are 90 degrees to the servo body. Now, from the side, take a look at the holes on the aileron control horns and make sure they line up with the hinge line. If not move them until they do. Once that is done, connect the control rods and adjust the clevis until the ailerons are properly centered.

Your throws should not be fairly equal. Proper geometery is very important.

Does this plane use a single aileron servo or one in each wing? How much differential does it have? Some planes have aileron differential built into them, it may not necessarily be a problem. I'm not 100% familiar with this plane though.

I just rechecked all of the geometry; it is perfect. So now what?

it has four servos in the wing: 2 for ailerons and 2 for flaps. The airlerons are plugged into the receiver at aileron and Aux 1. The flaps are plugged into the Gear with a switching y-harness.

How much are the ailerons going up and how much are they going down? And does the left one move the same as the right one?

Give us some measurements and we can help a lot better.

And check that your radio isn't the problem. What bubba said.

I've built a couple of those airplanes. The manual is very good describing the rigging. And has a pretty good section on setting up the radio.

The manual has sections for a number of JR radios.

I'm guessing, but you've got a 6 channel receiver don't you? And you're using Section 19 in the builder's manual to setup the airplane, right?

When you're setting up a new aircraft, make sure you reset the radio's programming for that airplane in the radio back to the factory defaults before you start plugging everything in.

What's a "switching y-harness"?

If you use a standard Y-harness, one of the flap servos will have to be a reversed servo. according to the builder's setup manual for the radio setup that shows a y-harness for the 2 flap servos.

I like mine that way.

Both servos move up 1/2"; they move down only 1/4"

My radio JR XP6102 is not in the manual that came with the plane, so I downloaded the intructions from Horizon Hobby, and followed them exactly. Maybe I should reset back to factory settings and start over?

I'm sorry; I just checked Programming Guide I downloaded from Horizon; it's a reversing Y Harness (and the flaps work just fine)

So it will fly correctly that way, huh? I just wanted to be sure that it's going to turn!

Hi!
All JR radios are programmed the same way. Have you checked your transmitter for differential trow???
If your mecanical set up is alright (servo and linkage)...then you must have had differential programmed in your radio...
and it could easily be fixed

Regards!
Jan K

Exponential affects the rate the servo moves versus the rate the stick moves. It does not affect the distance the surfaces move at full stick movement.

Full movement of the sticks will get full movement of the surfaces. The amount of exponential will not change that.

If the ailerons are moving twice as far one way than the other, then either the airplane is rigged incorrectly or the radio has something set incorrectly.

If the ailerons are on individual servos, and are moving the distances you described (both up twice as much as both down) and your rigging is "square", then it sounds as if one of the special functions is working to inhibit the downward movement.

If I were you, I'd post your problem in the special support forum for JR radios.

If with that radio you can set your end point adjustments as with a futaba, that might be something you may want to look at.

Darock:

IMHO you are on the right track.

It is very likely that he set up his linkages with the servos not centered.

The JR radios permit you to save trim settings which become the default "zero" point if not cleared when transitioning or setting up a new plane.

In this case I'll bet that he does not actually have the servos at their zero point and has compensated by turning the arms so that they LOOK like they are equal.

This creates exactly the condition he is discribing, namely that all the linkages and throws and settings are correct but you end up with more travel in one direction over another.

Subtrim should also be looked at in the radio.

Yes, and it also sounds as if it's possible that a spoileron setting is active. Although I'm not sure how that radio would be set for spoilerons.

NewFlyerGlen,
Page 34 of your JR manual describes the SubTrim Function and it's screen. The subtrim is maybe the worst residual setting. If it's left over from a previous model, or was inadvertently set on a new one, it's a killer and will lead you to rig your servos wrong.

And Page 43 in the manual describes the Servo Travel Screen and how to punch the buttons on your 6102 to see that screen. It is very useful to see all the radio's settings for all the servos. You can see if the aileron servos are in fact zeroed. You can also move all the sticks to see if mixes are in play. It'll also give you a graphic picture of what your dual rate settings are doing. Lots of things to see. But best of all, you'll see what the radio's settings are when you aren't pushing any stick at all.

And the best advice of all....... go to a club field and see if any JR flyers will take a look. Find an experienced one.

The airplane will fly fine with the differences in throw. Your radio is capable of end point adjustment. Read your manual, it will tell you how to adjust the end points on the servos.

Regards,
doubledee

I had a simialr problem with my JR XF631. I had the plane set up for flaperons, and one of my servos had way more throw than the other. I tried several things to get it to work, and I was finally able to fix it by seting the both of the dual rates equal to eachother. Whether this fixes the problem or not, I wouldn't fly until you figure it out. Good luck!

LT-40

Whether the differential is caused by your radio or your linkage is irrelevent.

The plane will fly just fine that way - In fact, it is desireable to have them go up more than down.