Individual Leadout Adjustment

[Jared Hays]

So what is the affects of adjusting 1 line at a time.  I have got a few flights in on my new Strega and I've gotten the major trimming issues corrected but I notice I can adjust my leadouts individually.  I have good line tension through the pattern so were pry talking minuscule results but what can I expect if I move the front line forward or back and then the back line? Any ideas?

[Bob Whitely]

Well, If the plane tracks, turns, has no wiggles, exhibits absolutely no bad habits
and as you say has perfect line tension, lands and takes off as described in the rule
book then you are one of the very few that have unknowingly got the leadouts
in exactly the correct position. Just move them and see what happens, that's
what most of us do. RJ

[Jared Hays]

Well I did move both back about 1/4 inch from where the factory had them but guess I'll just have to try them individually and like you say see what happens.

[Brett Buck]

So what is the affects of adjusting 1 line at a time.  I have got a few flights in on my new Strega and I've gotten the major trimming issues corrected but I notice I can adjust my leadouts individually.  I have good line tension through the pattern so were pry talking minuscule results but what can I expect if I move the front line forward or back and then the back line? Any ideas?

   The theory is that the line that you are pulling on gets tighter than the other (like, the up line has more tension when you are giving up control) and so the position of the leadout guide influence the yaw angle differently depending on which way you are turning. In the extreme, if you peg the controls completely, only the leadout guide for the tight line matters. That will hypothetically allow you to alter the yaw angle depending on which way you are turning. A typical example is to correct for perceived gyroscopic precession, by making the "up" line the front one, and then adjusting the leadouts to torque the airplane nose out on outside turns, to compensate for the supposed nose-in precession torque on outside turns.

     As usual, Bob is correct, the most effective way to see what it does is to try it (under carefully controlled conditions). I haven't found differential leadout adjustment to be particularly effective. After trying a bunch of stuff over the years, my "up" line is the rear leadout, and I put them about as close together as I think I can without them binding on each other. Maybe you can make use of it, but it's not nearly as straightforward as it might at first seem.

    Brett

[Jared Hays]

Well that's another thing.  On all of our previous stunt ships we have had the up line be the back line...This Strega the up line is the front line...Not sure if I like that yet.  I can tell you I also have the brodak cardinal ARF profile and the up line is the front line and I hate the feel of that plane its just weird as hell fly's funny I think, and its terrible in any wind.  The Strega seems okay so far, nothing like the Cardinal with the lines reversed from what I'm used too but totally different aircraft as well.  I know there is a thread just on that topic as well but for me the jury is still out on that. 

[Brett Buck]

Well that's another thing.  On all of our previous stunt ships we have had the up line be the back line...This Strega the up line is the front line...Not sure if I like that yet.  I can tell you I also have the brodak cardinal ARF profile and the up line is the front line and I hate the feel of that plane its just weird as hell fly's funny I think, and its terrible in any wind.  The Strega seems okay so far, nothing like the Cardinal with the lines reversed from what I'm used too but totally different aircraft as well.  I know there is a thread just on that topic as well but for me the jury is still out on that. 

     I would be very surprised if the front-up leadout is the biggest problem with the Cardinal. Put them as close as they can get and that will minimize the effect.

     The problem with the Cardinal is that the flaps are much too large. It took tremendous effort to get it out of level flight, but once you got to a certain amount of control pressure, it wanted to jump around the corners. Shortly before the 2006 NATs, we took our flying buddy Paul Ferrell's Cardinal (from a kit, not an ARF, but it's the same thing) and cut about 1/2" off the chord of each flap. That made it fly a lot better and much more consistently. Of course, he ended up winning Senior at the NATs with it. Compare the picture below with the original. It ended up flying much better than the ARF Strega some local wise guys had at the first ARF-Off several months later.

   Brett

[Jared Hays]

hmm interesting.  I will have to do that cause otherwise I was about done with that bird.

[Tim Wescott]

Jared, I'm not sure what level you're at, but I don't think up line forward/up line back matters much until you're within striking distance of placing in Expert at your local contests.  When you are, as Brett said, you'll probably find that it's a matter of personal preference.

Mark the current positions of the leadouts before you take Bob's advise and start playing with them -- that way you can put things back to "good".

[Jared Hays]

Yea I'm there within striking distance.  Just on 80's technology but hey its worked great so far.

[Jim Thomerson]

I was, back in the day, a mid level Advanced flier. I put my leadouts as close together as I am comfortable with.  On a 1/2A I run them out one hole.  I am a great believer in adjustment.  I generally start out where I think they should be, and move them 1/8 inch at a time if I think they need it. 

If you fly well enough to be able to tell what your airplane is doing, moving them around is informative.  It is good to have your own experience to help you understand things.

[Randy Cuberly]

I built and flew one of the Profile Cardinals for quite a while back when the kit was first made available.
I agree with Brett on the basic idea of the flaps being too authortatitive in relationship to the elevator and made a change on mine that I feel is a little more effective overall than reducing the size of the flaps but accomplishes the same thing without actually reducing to overall wing area.  That change is to simply reduce the flap travel relative to the elevator travel by using a significantly longer flap horn and an adjustabel elevator horn (Tom Morris on mine).
I think mine wound up about 2/3 to 1 ratio, maybe even just a little less than 2/3...
It does make a vast improvement in corner and tracking ability.  With those changes I found the Cardinal to be a very good flying airplane and very competitive!

Randy Cuberly

[Brett Buck]

I built and flew one of the Profile Cardinals for quite a while back when the kit was first made available.
I agree with Brett on the basic idea of the flaps being too authortatitive in relationship to the elevator and made a change on mine that I feel is a little more effective overall than reducing the size of the flaps but accomplishes the same thing without actually reducing to overall wing area.  That change is to simply reduce the flap travel relative to the elevator travel by using a significantly longer flap horn and an adjustabel elevator horn (Tom Morris on mine).
I think mine wound up about 2/3 to 1 ratio, maybe even just a little less than 2/3...
It does make a vast improvement in corner and tracking ability.  With those changes I found the Cardinal to be a very good flying airplane and very competitive!

    Not to discount your experience, but Ted and I tried that with Paul's airplane, and the adjustments were too coarse on the kit hardware. It was either stock which was way too much flap or the next hole in the horn, which was way too much elevator. In most of my previous tries where I changed the ratio AND changed the flaps to replicate the same effect, I always wound up preferring the right-size flaps, and more or less 1:1 controls. May be a different story at altitude, of course. But I am interested to learn that stock was too much even in Tucson.

    I was amazed how difficult the airplane was to fly, stock, at a reasonable maneuver size. You just can't get it turned quickly enough to wind up with acceptable straight sections without flying it 60 degrees high. I couldn't manage it even knowing what the problem was ahead of time.  With the flaps trimmed down, it was fine.
 
     I wonder how many people built the kits or the ARF and thought the problem was lack of skill.

     Brett

[john e. holliday]

I wonder how Windy flew that set up or was his different than the kit?

[Brett Buck]

I wonder how Windy flew that set up or was his different than the kit?

  His airplanes of that general layout tended to have the same problems, both from external observation and from people who have flown them. People can manage just about anything look pretty good with infinite amounts of practice. Paul Ferrell flew the Cardinal fairly well before modification, because he didn't know any better.

   Generally, a lot of people are held up by their preconceived notions, and make it much harder on themselves than it really needs to be. There's a range of personal preference, but it's not nearly as wide a range as most people claim.
 
      Brett