I'm a newbie and bought a Nexstar Select for my trainer. I've read through everything and have completed al the basic ass'y and setup tweaks, HOWEVER...

I can't figure this one out! One aileron moves up about 1/2" and down about 3/8" as it's supposed to. The other moves about half that much on both directions. What gives? I've adjusted the rods to set neutral position, but can't se for the life of me what could be causing this and worse, how to fix it!

Please help!

Is there a single servo driving both ailerons. Or do you have one servo on the left aileron and a separate servo on the right aileron?

Are both the control horns attatched to the same hole on the servo arm? There should be three...

on my nexstar, one of the ends on the control arms of the alierons was about 10 rotations higher than the other (it was almost not on at all) make sure they are spun to the same heiht...

Sorry, here's more detail that I obviously didn't think of when I posted the question:

It's a single servo setup with symmetrical rods off each side for the two ailerons. The rod ends are now different lengths due to my tweaking to get the ailerons "neutral", but I don't see how adjusting their length would affect the total throw in both directions.

Hope this clears up the picture a little.

If one rod is longer than the other, the servo has to turn less to move aileron further. Therefore you will get higher throws on the rod that is the longest.
With the shorter rod, the servo has to move more to push the rod the farthest. So you will end up with different throws when the constant is the travel of the servo.

Check which one is the one with the least throw - is it the one with the shorter rod? It should be.

Shakes,

What you're saying is not true. Lengthing a rod has nothing to do with the total amount of travel of the rod and/or aileron. The rod will still travel exactly the same distance, it will just start from a differnet point than it did with a shorter rod. Make sense?

The rod length is adjustable only to adjust the "neutral" or "at rest" location of the aileron.

Buf if one rod is too short, you'll have to adjust the clevis further or change the way the servo arm is centered on the servo to get both ailerons neutral. If you end up having to change the position of the servo arm on the servo because the rods have a great difference in length then the servo will have less travel in one direction than the other for that particlar torque rod. Pull might be greater and push might be lessened by that. Also, the way a clevis works is to adjust the actual length of the rod in small increments. So we're talking about length that is greater than that of what a clevis can adjust.

I had similar trouble with mine. Go purchase another servo and use a servo for each wing. That is a great feature of that plane. The servo trays are already built into the wing. Better response, more accurate control

Shakes, I see what you're saying. The rods themselves are identical. The lengths are a little different due to the adjusted cleviese to set neutral, that's all.

Pelham,
Thanks for the input. Not exactly what I wanted to hear, but still good info to have. I've never flown before (on any plane) and this is to be my virgin flight (very soon I hope). For that reason I'd really like to get this thing to wrok correctly without any modifications, at least not YET. Harumph.

Thanks guys!

Anyone else have any ideas how I can make this work, or at least get it to a point where it won't throw me off much as a beginner (and increase my odds of crashing)?

I think that he is referring to the torque-rod arms, not the push-rods. The length of the torque-rod arms definately makes a difference in the amout of control throw. The shorter the torque-rod arm (or the lower the position of the clevis fitting on the arm), the greater the control throw. In the case of the servo horn, the longer the servo horn (or the farther out toward the end that the pushrod is fitted) the greater the control throw.

You should attempt to have the servo horns straight across at neutral control input, with both push rods fitted to the same hole on either side, & both torqe-rod fittings at the same height. If one aileron "throws" less, lower the height of the fitting on the torque rod. Keep adjusting until throws are the same on either side.

Yayyyy for Britbrat, someone finally got it right. MrChubs1- if you follow that advice you will get it right.

MinnFlyer- can you post the drawing for him that you did before? I think it was for Prophex?? or Smoggyboy?? not sure which.


Bruce

Thanks Brat - that really does clear things up for all of us I think. Now my only question is: How do you adjust the height on the arm? It appears to be threaded, but when I spin it, the plastic thingiemerbob doesn't move up or down. I've also not been able to press it down with pressure from a screwdriver (assuming it could just be a ribbed surface, not really threaded).

The threads are pretty fine, you may have to turn 3 turns before you see a significant difference.

If you have a digi camera, take a picture of your setup and post it.

Don

Ya, depending on how different the height differences of the clevises are, you might have to turn the one clevice 8 or more turns before you see the 2 clevises starting to look about the same. Sounds like a lot but the plus side is you can make very small adjustments to get the plane trimmed out perfectly after a few flights. [8D]

Actually, my digicam crapped out recently. I ordered a new one and it should be here by the end of the week. Maybe I can test it out with some plane pics.

I tried spinning the plastic doohickey and must have given it 15 turs with zero movement. (And no, the rod isn't spinning with it.) Guess I'll need to set up something where I can hole the rod still while I cram down on it to force it down. Just don't wanna break it.

Stay tuned!

(Thanks for all the help so far, guys!)

umm...if you cant get the throws right without having to really force anythng, contact hobbico, their customer service is awesome.....

MrChubs1- let's make sure you are talking about the nylon fitting threaded onto the upright portion of the aileron torque rod, correct?

If you can't turn one and have it go DOWN, can you turn the other and have it go UP to match the other? As long as we can get them to match, THEN we will worry about the amount of throw.

Try that and let us know. [sm=confused.gif]

I have a NexSTAR at home, not used it since last summer.. but took a look at it last night. Both my torque rod horn brackets are movable and adjustable so it may be that yours are somehow not properly threaded or stripped. You may wish to contact Hobbico. When I bought my NexSTAR, I had a problem with one of the engine mounts. They IMMEDIATELY sent me a replacement. Later on, when I crunched in the main landing gear on the left side, they said that they could replace the fuselage for me because they did not have a replacement part for that landing gear setup they were using. I declined and just used epoxy and fiberglass to fix it. My point is that Hobbico is very good with their replacement policy. Perhaps they will want you to return the wing halves and send you a new pair. Unless, of course, it's the nylon torque rod horn that's stripped and not the actual torque rod. Check that. If it's just the nylon torque rod horn that's a quick and simple fix... go to your local hobby shop and pick up a replacement. (probably 4-40 sized).

After that, you can adjust the throw on both the torque rod end as well as on the servo by setting the link closer or further from the center of the servo... that's why there are several holes in the servo arms.

Thanks guys! Yes, I am talking about the nylon end on the torque rod. Unfortunately the other one is right at the top of the rod, but still has plenty of throw.

I guess it could be stripped. I'll try forcing it down the rod and if that works, just gluing it in place, at least for now. I can always get a new nylon piece later.

This should be all you need: http://www2.towerhobbies.com/cgi-bin...?&I=LXD947&P=0
or something very similar. Your LHS should have these, not worth bothering mfg and waiting for IMHO.

Sorry about that.. I accidentally clicked on 'report'. Not sure what that does, but it is a total mistake and I apologize.

Anyway, Bruce.. that's the gadget I was looking for and what he needs... unless the shaft is the problem. He can fix that with a die (tap?) in 4-40 (hopefully) and re-thread it if it is stripped.

On my NexSTAR, the aileron torque rods started to get loose after a fashion. They never put any epoxy or any kind of adhesive along the brass tube in the wing that the torque rod passes through. So, I had to prod and poke some epoxy in there hoping that I didn't get any on the shaft itself.. which I did not. But, eventually the other side started to get sloppy. Fortunately, I solo'ed and moved on to something without torque rods (dual aileron servo's on two channels). Much better than torque rods.

Torque rods may also be metric, depending on where they were made. Dubro fittings may come unthreaded but not likely, should thread onto metric rod too as long as diameter isn't too far off. may be metric version available or may have to get from mfg after all.
On your loose torque rod bearing tube problem, could you have put a few drops of thick CA in there, and then "kicked" it if it started to run? Sometimes, if I'm worried about that, I'll put the kicker on first and then the CA. Never gets a chance to run that way.

ps. don't got no "report" button on my confuser. What for you talkin bout??? [sm=confused.gif]

Well, to be honest with you, Bruce, I have not flown the NexSTAR since shortly after I solo'ed. I've been flying the Tiger 60 and my new Midwest Aerobat. The loose torque rod has been temporarily fixed by packing epoxy behind the brass tube.

I am thinking of selling the trainer to someone that needs a good trainer, ie. already setup and ready to fly, with the note that the torque rods could wobble at some time in the future and let someone else get the benefit and get flying.

Well guys, I bought a small package of the thingiekerbobs today. I'll try to find time tonight to try out the repair. (fingers crossed)