I have a nexstar, gone through the traing, the aids are all off and Im have fun flipping my bird all over the sky. My question is if I move the control rods on my Alerions to the top hole on the horns what would happen? and is this good? I want a little faster roll on the bird.

Im new to the, please be gentle!!!!!!!

Justin

It would make the surface move a little faster an a little further. Do to the fact that that plane has a ton of center sag(diheidral) in the wing you will never get it to roll like a EDGE 540. Just keep in mind its a good gentle flyer. an thats it.

That was as gentle as i could be canada........

That would actually slow your roll rate... go to the inner holes on the control surface and the outer holes on the servo arm. Be aware this is a lever system and you loose mechanical leverage by doing this and it puts mor strain on your servo. Good luck have fun and don't go straight to maximum deflection.

Rereading your post I can see how "upper holes" could mean the same thing

So here is an answer that covers all bases........................

If you want more throw from your ailerons, move the connection on the aileron horn IN toward the hingeline. You can also move the connection on the servo arm OUT.

With almost any model, it's quite safe and within most pilots abilities to change that setup a hole at a time, and test fly. You should feel the difference, but it's not going to suddenly be greatly different.

And with standard servos on that airplane, you won't need to worry about the ailerons being too great a load no matter how you rig the connections.

If you haven't added the second aileron servo, you should. Your plane is all set up to do this. Check your manual. I did mine, it's easy to do, and will take the strain off of the single servo. Just make sure to use the same make and model for each servo.

Don't forget that changing the 'hole' for the clevis will change the trim. You will have to adjust the centering again once you move that clevis to a different position. This will always require re-centering and a slow, very careful initial flight afterwards to get the trim right.

CGr

ive got a nexstar also how much of a job is it to add the second servo and what is the advantage of doing this will the plane have a extra control if you do this?

Not much effort. You've placed one servo so know how much that was. This is placing two. You will have to place aileron horns, and make pushrods. And you'll probably need two extensions for the connections to the "Y" harness. You'll need the "Y" to plug into the receiver and to bring the two servo leads to one lead in to the receiver.

You will only get "extra control" out of the arrangement if the single servo wasn't powerful enough to drive two ailerons. Probably not the case if you were using a standard in that airplane for the ailerons.

Check out page 24 http://manuals.hobbico.com/hca/hcaa17-manual.pdf
You probably won't notice any difference in the way it flys. I did mine mainly to gain a little "building" experience. But I have the RTF Nexstar.

If you want a more responsive bird as well might try moving te CoG back bit by bit and see how you go as again it'll clean up / make rolls faster but do it slowly and carefully and not at the same time as moving the throws. Be careful of going back too far as well as it can make it horrible to fly in which case you've obviously gone too far.

RCKen has a great graphic that shows control horns with a description of the differences in the holes and how they affect deflection. Hopefully he'll post it. I tried searching but didn't come across it. I'll keep looking though.

I found these - hope they help.

Excellent advice, but keep in mind that as you move the CG aft, the elevator becomes more efficient. So you will probably need to reduce it's deflection as the CG move takes effect. You can wind up with less throw than the model build instructions suggested.

Most people think that moving the CG aft is a death defying act, but it's not even close if you understand what's happening. The elevator gets more efficient, and unless it is re-rigged, the effect of moving the elevator stick on your TX is increased. So re-rig it (best done on the model) and gain even more value out of the CG move. And have an airplane that's actually a bit easier to fly and will do more in the air.

rwright142,
Those are the same graphics that I would have posted!!!

Ken

All good advice. Also keep in mind that it is usually desireable to use the outermost hole on the servo arm to get the maximum leverage from the servo and vary the holes in the horn on the control surface for trim. Because the servo moves in an arc you also get diminishing returns the farther it has to rotate. (towards the end of the rotation it's moving the rod as much sideways as back-and-forth). If you can keep it to 60º, 30º either way, you're in tall cotton.

Anymore I use the outer servo hole (generally on a 20mm/1" servo arm), the next to the last control arm hole and use digital sub-trims and endpoints to get where I'm going.

An important fact to take into account is that as you get higher performance airplanes you have upper limits of control throws that the plane will accept(by way of higher performance I mean more then a trainer) Some planes will snap when you have too much control movement, because the surface will stall. This is very disconcerting when it happens the first time and it usually happens at slower speeds and if you are really unlucky during a landing. Just be aware that when you are playing with throws and cg points that you do your experimenting up high and if you have dual rates you might want to program the low rates to be at a known safe condition.

I figured so, but I could not wait any longer for you to respond!

And just for the record, those are MY graphics!

HAHAHA - ok, your royalty check for $1.50 is in the mail...

Charlie P,
You mention end points, what are they ?????

When I'm setting up the throws I simply use a ruler which isn't neccassarily the most accurate way of measuring how much the surfavce is moving and if I want more / less just dial it into the transmitter so that up / down on both left and right are near as damn it the same or as close as I can get and then for dual rates just a % of full rates. Is there any more accurate way to do it ???????
Cheers,
Neville

Computer radios have adjustments they can make internally. End Point Adjustment is one of them. With that function, you can adjust the transmitter to tell the servo to move farther or move less. Unfortunately, it doesn't always work that way at the airplane. The best way to adjust your surface throws is to do it with the hardware in the model, and then use the radio to fine tune that. When you attempt to change the surface throws with the radio, the accuracy of the movement and the power from the servo can be messed up. You really do not ever want the transmitter to be trying to move the servo more than 100% for example.

Yeah, leave the radio set for 100% for it's throws and use 100% for full rates (whatever less for low rates). Set the throws with the connections at the horn and the servo. And fine tune with the radio. Truth is, don't fine tune, just go fly with the throws close to suggested and see what throws work better with your CG. Tune the CG and the connections in the model to get the response you wish from the airplane, and if you can't get the throws fine tuned in the model, THEN mess with the endpoint adjustments.

One of the biggest mistakes made with computer radios by the guys who think it's easier to setup their airplanes in the radio instead of when building happens all the time. They slap the pushrods into the airplane wherever and then start cranking the TX throws up over 100% when the connections have screwed the throws in the airplane. If you've got the servo arm connection in the farthest out hole, you're really not going to get appreciably more surface throw by going past 100% in the TX. All you're really going to do is screw up the feel of your stick. You wind up with what amounts to the same response you'd get from the stick being set with reverse exponential.

It's actually sort of funny sometimes.

We've got a fairly loudmouthed guy at one field whose mission in life seems to be to show everyone how his computer radio has made the hobby so much easier for him. And he usually winds up yelling about how "he paid big bucks for it, why not use it".

I got him to show me his endpoints the other day when he very quietly asked how to get his throws "just a bit more than normal". Turns out he's got everything to the max in his radio. And he can't get the airplane to stall. Not enough elevator throw. He's got the servo arm connection at max out. And hasn't got the arm centered. And when he pushes the stick to max, the connection basically goes around the bend (what CharlieP mentions in post#16 above) about half the movement.

It's really a bit pathetic actually. This guy said that he really liked the way the airplane responded with "the extra throws he was getting out of the radio" and wondered if there was a way to modify the radio to get more. He really didn't want to hear what was wrong and went off looking for someone "who knew more about radios."

That was one advantage of moving through free-flight to control-line to gliders and eventual powered R/C. I remember when "proportional" was still a big enough step that radio manufacturers touted it in their ads. (The servos moves proportionally to the stick movement). The basics haven't changed. First you get the airframe squared up, then you get the controls trimmed, then you tweak.

I'm as guilty as anyone now in that I get "close-enough" and pull an end-point in to stop a servo binding at full throw instead of adjusting a rod's length. I center the servos (radio on) at 100% sub-trim, form and install the control rods, and then digitally trim. And I confess I love the ability to temper wild throws with adjustable exponential near the centered range to "smooth out" an extremely sensitive model.

As I fly and make any trim adjustments I bench the model after I'm back home and make the mechanical adjustments; eventually getting the digital trims minimized. I NEVER leave a trim switch/button (the ones on the radio face) so that I have to fly a model with those off center. The throttle is the only exception, and even then I like the trim centered and a seperate idle-down and kill assigned to switches. Back when trims were sliders instead of only display bars it was foolish and dangerous (to the model) to rely on something so easily bumped out of position.

As daRock says: any throw over 100% in the transmitter's setup is probably just a sign of a bad mechanical set-up and you're fooling only yourself. Those kind of adjustments get the extra throw in one direction by robbing the opposite end of the range or reducing servo sensitivity.

In addition or instead of moving the control linkage (and you might already know this) you can execute a much faster and prettier roll by using rudder and elevator. Airspeed helped rolls on my trainer too.

Also, moving the cg back will help roll response and all other response too. Just be careful if you do this. Make sure you do some reading first.

Another thing, it looks pretty bad but I saw a guy extend the ailerons on his trainer by using balsa sheeting glued to the existing aileron. So the aileron was no longer 1.5" wide, but like 3" wide. Granted it looked bad, but WOW! I'd never believed a trainer would roll like that! This is kind of a brut force method though.