Roll / Hinge on Outsides

[Peter in Fairfax, VA]

On a really tight, low-speed outside square, my Vector rolls (hinges) if I hit it hard.  Small loss of line tension.  With just a little practice, I can keep up the speed and not be concerned.  However, any quick tips on how to trim out the hinging?  Brodak 40, TT 11x4.5, 60'x.015.

[Ken Culbertson]

On a really tight, low-speed outside square, my Vector rolls (hinges) if I hit it hard.  Small loss of line tension.  With just a little practice, I can keep up the speed and not be concerned.  However, any quick tips on how to trim out the hinging?  Brodak 40, TT 11x4.5, 60'x.015.

If the roll is to the outside (eg. the outboard wing drops) I have had success by increasing the size of the outboard flap.  It is also a sign of too much tip weight.  If you are sure that it is not too much tip weight try a fixed tab at the end of the outboard flap.  It works for me.

Ken

[Dan McEntee]

On a really tight, low-speed outside square, my Vector rolls (hinges) if I hit it hard.  Small loss of line tension.  With just a little practice, I can keep up the speed and not be concerned.  However, any quick tips on how to trim out the hinging?  Brodak 40, TT 11x4.5, 60'x.015.

     Remember the old joke on Hee Haw where the guys says the the Doctor, "Doc, my arm hurts when I do this!"  And then the Doctor says, "Well, don't do that!!"

     But seriously folks, you say that the model does this when you hit it hard at low speed, you drop the wing. Is this just on the second outside square? Or on the outside square part of the horizontal square eights? If it doesn't do it on the insides, it's more likely that the trouble is in the way you control outside maneuvers.  If you really "hit it hard" you are yanking the model toward you. Outside tricks tend to make all of our butts pucker, and depending on the situation you may be making it worse. If you are flying at tyou best, and have no problems, then the model may be in pretty good trim. If you know you are messing up, and the issue flares up, you know that you are the problem. You can take a perfectly trimmed model and still make it do bad things.  I think in this case, you have bled off speed in the previous corners, and that is your issue. You can't trim for that. if you do, it will affect trim somewhere else. Work on flying smoother, and you have not mentioned what your lap times were. try speeding it up just a touch. If you are at 5.5 seconds, speed it up to 5.3 and see what happens. Whatever the speed is, two tenths of a second in lap times can make a noticeable difference. maybe experiment with some different props. Try an APC 11-4 or I used an APC 11.5-4 a lot on my Brodak .40s. Practice, experiment and analize what you got before you make a big trim change.
    Type at you later,
    Dan McEntee

[Ted Fancher]

On a really tight, low-speed outside square, my Vector rolls (hinges) if I hit it hard.  Small loss of line tension.  With just a little practice, I can keep up the speed and not be concerned.  However, any quick tips on how to trim out the hinging?  Brodak 40, TT 11x4.5, 60'x.015.

Peter,

Check your handle at neutral before takeoff.  If you have adopted the "common" relaxed "pistol" grip neutral setting it is possible that in order to turn "outside" squares you have to pull your entire handle down and toward you to achieve the "down" input necessary to make an outside square corner.  When you do that it pulls the airplane toward you and, when you go back to a neutral handle setting for the following "straight" segment of the square your arm/handle move back toward the airplane in order to achieve the pre-set  "pistol grip neutral" necessary for your ship to fly a "straight" path.  When your hand thus goes toward the airplane it is the motion of the hand toward the airplane that causes the loss of tension.

If so try (carefully) to force yourself to adjust your handle so that the handle and your wrist are  "vertical" when the flaps/elevator are at neutral.  Then ""very carefully"" fly a pattern and see if the loss of tension in outside corners hasn't disappeared.  Be advised that this experiment is only appropriately accomplished with a handle that doesn't include built in "biased toward a pistol grip" neutral setting.

This is a very important factor which encourages fliers to utilize the "vertical" handle at neutral so that all inputs to fly the pattern are primarily accomplished  by a hand/handle pointed consistently at the airplane and the handle/line spacing adjusted so that "most" control inputs can be accomplished by finger/wrist and, only if necessary under adverse weather conditions, very modest elbow  movement so that the airplane is, to the greatest extent possible, never pulled toward you and then abruptly released to again reach the full line limited distance from the pilot.

The best way I know of to "preset" such a setting is to, prior to flight, insure that full up and down control are achievable with only wrist and finger input.  If you have to pull your flying arm toward you to get full down at rest you're going to have to do the same thing in flight.  Once you've performed a tight corner via pulling the airplane toward you to get the controls deflected a predictable period of time will be necessary for it the airplane to return to full circle circumference during which the pilot will...totally predictably...experience  what he believes is an aerodynamic loss of tension which is, actually, the result of the return of the handle "toward" the airplane after pulling "it" and "thus" the airplane toward him in order to perform the previous outside corner.

Yet another reminder that handles biased so as to insist that the "pistol grip" be utilized make flying stunt more difficult than it really is.

Ted Fancher

p.s.  If, in fact , you use a "proper" vertical/unbiased handle at neutral setting forget all the above.

[Ken Culbertson]

As a reformed handle bias addict I can tell you that everything others here have posted is more likely to be your cause and, if you are flying at the Expert or higher levels of Advanced then you best make the changes they suggest now because I can tell you from experience that it takes a long time to change the subconscious.  However, it is well worth it.

The suggestion I made earlier should only be tried if you are already using proper form and the right prop.  I forgot to mention that my solution has another symptom other than the wing dropping on slow outside corners, it will also do it on the 120 degree insides at slow speed. 

Since I acquired most of my bad habits learning the pattern on the football field of the Old Fairfax High School I wish you well in overcoming this.

Ken

[Peter in Fairfax, VA]

I do have a neutral handle.  Still, I'll try to observe my technique more closely for any handle pulling problems.

Regarding the gyro procession, would adding a spinner makes that worse, as well, or just the prop?

[Dave_Trible]

If the roll is to the outside (eg. the outboard wing drops) I have had success by increasing the size of the outboard flap.  It is also a sign of too much tip weight.  If you are sure that it is not too much tip weight try a fixed tab at the end of the outboard flap.  It works for me.

Ken

Yep!  Barring the handle issue Ted describes.  If you can adjust your tip weight easily, just pull some.  If not try to stick a clump of clay to the INBOARD tip just to test fly and know if thats the problem.  Then you will know it's time to dig some tip weight out.  There are a few more subtle things that can work against you like rudder offset or leadout adjustments-but go for the low hanging fruit first. 


Dave

[Joe Gilbert]

Check flaps to be inline with each other. That place in pattern shows trim problems real quick and lack of drive will cause this to show also. 

[Jim Svitko]

Check flaps to be inline with each other. That place in pattern shows trim problems real quick and lack of drive will cause this to show also.

Check the elevators, too.

[John Leidle]

  Took a new plane to the field a couple years ago, it hinged at intersections & squares & triangles . Pat Johnson suggested remove  tip weight slowly.... I removed a lot of it & guess what it is now a rock steady flyer.
  John L.

[Steve Helmick]

Some good tips already posted, but I'll add that since the model has slowed, it seems to me that our OP is not backing up as the trick progresses. That speeds the model up by increasing line tension. If it's windy, follow it downwind to reduce line tension and keep the speed down.

I once asked Paul what works best for backing up, and he said to just shuffle the feet, as the conditions require. Long strides jostle the handle and induce bobbles at the plane's end. Body position and foot action are a big part of good stunt piloting, as well as placement of the trick to the wind. You've got two laps between tricks to remember what trick is next, and think about where you'll start it, what your body position should be, how your feet will be positioned when you start, and what the feet will do if the wind conditions require either backing or following.    Steve

[Peter in Fairfax, VA]

The first time it happened on the outsides, I backed up about 12 feet. Subsequently, about 3 feet.

The lap times, the rotating mass, the flying technique points, the flap/elevator alignment, the tip weight are all good ideas.

[Steve Helmick]

The first time it happened on the outsides, I backed up about 12 feet. Subsequently, about 3 feet.

The lap times, the rotating mass, the flying technique points, the flap/elevator alignment, the tip weight are all good ideas.

I once had to fly an official during zero wind, thermally conditions. In the Sq.8, I backed up as I had in the previous maneuvers, but eventually realized that because of the very slight drift and thermal activity during that trick, I should have walked it the other direction. Nobody said this stuff was going to be easy! Steve

[Peter in Fairfax, VA]

Another basic suggestion from a previous flight session review was to add an adjustable outboard trim tab, as the plane was coming in at me previously, especially on landing.  I did add the trim tab.

It's possible that my wings simply aren't level.  This is a little hard to gauge from the center of the circle, as my favorite observers were not at the field.  When I mentioned that the tendency to roll was reduced on subsequent flights yesterday, my apologies that I forgot to mention that I also adjusted the trim tab to favor inverted flight.

Trimming is an exercise in trying to focus adjustments on one variable at a time.

[Howard Rush]

I’d do the following before flying the airplane again:

Get rid of the adjustable tab (the fixed tab is for a different, more subtle purpose).

Dewarp the wings, flaps, and horizontal tail surfaces.

Make sure elevators have the same deflection (elevator trailing edges line up).

Seal flap and elevator hinge lines.

If you can make roll adjustments by twisting the wing, set the flaps at the same deflection (align trailing edges).  Otherwise, never mind: you’ll have to tweak the flaps to level the wing.


Now fly it and follow the Walker trim procedure.


I still haven’t found the picture. It’s here somewhere.