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Design => Stunt design => Topic started by: Skip Chernoff on April 15, 2017, 05:06:10 PM

Title: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 15, 2017, 05:06:10 PM
Seems like every stunt plane I own turns better outside than inside....what's up with that?
Title: Re: Outside vs.Inside turning ability
Post by: Mark Scarborough on April 15, 2017, 05:59:21 PM
Its not trimmed properly
handle neutral, elevator to flap bias
Title: Re: Outside vs.Inside turning ability
Post by: Dave_Trible on April 16, 2017, 09:09:06 AM
Mark touched on what I would say, but since it's a recurring issue on several airplanes for you it would be something about the control handle.  Your sense of level or neutral adjustment may be off and you may need to adjust it-then YOU or how you perceive it through more flying .  Also how the handle leads outs or line attachments are placed vertically in relation to your hand and wrist will sure change the inputs to the airplane.  If your attachments are adjustable move BOTH lines up a little.  That will more balance what you are feeding into the airplane.  We are all made a little differently so your feel can be quite unlike someone else's and your natural range of motion with the wrist  sort of controls how the handle might be adjusted.  This is also why you might find an excellent flyer who learned to fly with the handle upside down or horizontal that performs great but we would crash if we tried to fly that way.  We are trained to a feel so we have to adjust stuff to compensate.

Dave
Title: Re: Outside vs.Inside turning ability
Post by: Jim Carter on April 16, 2017, 12:32:49 PM
"a flyer who learned to fly with the handle upside down or horizontal that performs great ...."
Really ??? ??  You mean there really are others like me  ??? ??  So .... there is hope of performing a successful pattern  :-\??  WOW!!  %^@  LL~
Title: Re: Outside vs.Inside turning ability
Post by: Brett Buck on April 16, 2017, 01:54:36 PM
Seems like every stunt plane I own turns better outside than inside....what's up with that?

   I would guess that your handle neutral is with the handle tilted forward in what is called a "relaxed grip". I think it should never be used.

     Brett
Title: Re: Outside vs.Inside turning ability
Post by: RandySmith on April 16, 2017, 03:26:47 PM
   I would guess that your handle neutral is with the handle tilted forward in what is called a "relaxed grip". I think it should never be used.

     Brett


bingo  .....!!!   give that man a  cigar 
Title: Re: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 16, 2017, 05:05:59 PM
The handles that I  use are the Rayco wooden type with neutral adjustment only. They have very little overhang. I think the line spacing is around 4" or a little more. There is no bias adjustment. I'll try a handle with a bias adjustment and see how the planes respond...Thanks,PhillySkip
Title: Re: Outside vs.Inside turning ability
Post by: Brett Buck on April 16, 2017, 05:27:19 PM
The handles that I  use are the Rayco wooden type with neutral adjustment only. They have very little overhang. I think the line spacing is around 4" or a little more. There is no bias adjustment. I'll try a handle with a bias adjustment and see how the planes respond...Thanks,PhillySkip

     I am not sure what you mean about "bias adjustment". I am just talking about having the grip perpendicular with the lines, which is adjusted with the neutral adjustment.

     Brett
Title: Re: Outside vs.Inside turning ability
Post by: rustler on April 16, 2017, 11:59:56 PM
   I would guess that your handle neutral is with the handle tilted forward in what is called a "relaxed grip". I think it should never be used.      Brett

Hi Brett - always anxious to learn, can you expand on that a bit? One's hand has a certain range of movement. With neutral occurring with the handle tilted forward, I guess that means you have a reduced amount of "down" hand movement available. Why should this make for better inverted manoeuvres than upright?
Title: Re: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 17, 2017, 03:35:48 AM
Brett have you ever seen one of Joe Adamuko's handles? It has a series of holes top and bottom that the handle line goes thru. By cutting the line and selecting different holes you can move the line up or down, OR change the line spacing. The only problem is that once you cut the line you need to reswag one of the loops that gets attached to your control line. Joe keeps cable, a crimping tool and lead crimps for doing this at the field. By using this handle you can change the amount of movement in either direction for a given amount of wrist motion. You can bias the handle for more "inside" or "outside" throw.

I suspect that maybe when I'm setting neutral on my ships that my hand is not perpendicular to the ground. I'll check this out. I've been setting neutral with what feels natural in my grip.....Thanks,PhillySkip
Title: Re: Outside vs.Inside turning ability
Post by: Mark Scarborough on April 18, 2017, 08:27:11 AM
you may also consider obtaining a dfferent style handle, one that is more practical to adjust? I know I have adjusted my handles through the life of my airframes, so it can be an ongoing thing,,
Title: Re: Outside vs.Inside turning ability
Post by: Howard Rush on April 18, 2017, 05:12:44 PM
I'd look at the airplane first.
Title: Re: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 18, 2017, 07:21:10 PM
Howard,what should I be looking for?  I can adjust elevator trim via cleavis to give more up with flaps at neutral. What say ye?
Title: Re: Outside vs.Inside turning ability
Post by: Ted Fancher on April 18, 2017, 10:23:41 PM
Howard,what should I be looking for?  I can adjust elevator trim via cleavis to give more up with flaps at neutral. W
hat say ye?

Skip,

In my experience it is quite unusual to have a stunt ship that turns more aggressively outside than inside, especially if you fly with a "relaxed or  handshake" handle bias at neutral.  Do you, by any chance, fly upright clockwise rather than counterclockwise as do the vast majority of flyers?

What my good friend Brett described (a relaxed grip at neutral) generally results in more aggressive insides than outsides...the reverse of what you are experiencing.  If your initial description is accurate,  aggressive outsides and slow insides,  something unusual is to blame.

there are technical "aerodynamic" reasons why stunt ships often turn better inside than outside when flown in the "normal" counterclockwise when upright direction but it is counterintuitive that one would experience what you describe when flying in the "usual" direction.

The most likely "obvious" reason for what you describe would be the result of excessive down elevator with the flaps at neutral...which is equally "unusual".  Inasmuch as you've got the ability to adjust the flap/elevator neutral settings I would first do as you suggested; a turn or two at a time raise the elevator with the flaps at neutral and report the result.

FYI, in a lifetime of flying stunt I've had just one airplane that required such an adjustment and I've no explanation for why that was so.  I have, on the other hand, had a large number that required some down elevator at neutral flap to obtain equal turn rates with the handle set for "vertical" at level flight.

Try adjusting the elevators up a little at a atime and report back.

Ted Fancher

p.s. It's very important if you want to fly good stunt that you not let yourself believe the "relaxed" hand position at neutral is to your advantage.  Remember, you've got several options to increase handle displacement for insides: fingers, wrist, elbow and shoulder can all provide additional input for insides and all but the shoulder with ver y little need to pull the airplane toward you while doing so.  The only additional lever you've got to increase down input is what little wrist movement is left with a relaxed neutral and pulling your entire arm toward you hinged at the shoulder...a very inefficient mechanism that is all but impossible to relocate to an accurate neutral upon completion of a corner.  Doing so is not a recipe for winning expert competitions!
Title: Re: Outside vs.Inside turning ability
Post by: Ted Fancher on April 18, 2017, 10:34:57 PM
Skip,

p.s.  Be sure to look down the list of topics and find the one titiled "Stab Incidence" to better inform yourself on the subject of "decalage" between the wing and stab and its effect on turn rates.  (decalage is just fancy language for what you're describing when altering elevator deflection versus flaps.  The result of adjusting them so that flaps and elevators are not "neutral" at the same time is, aerodynamically,  the same thing as building the stab/elevator so that they are no longer at "zero" at the same time.  The technical terminology for that situation is that the wing and tail are at a different angle of incidence to one another; a status known as decalage.)

Ted
Title: Re: Outside vs.Inside turning ability
Post by: Brett Buck on April 19, 2017, 12:19:46 AM
Skip,

In my experience it is quite unusual to have a stunt ship that turns more aggressively outside than inside, especially if you fly with a "relaxed or  handshake" handle bias at neutral.  Do you, by any chance, fly upright clockwise rather than counterclockwise as do the vast majority of flyers?

What my good friend Brett described (a relaxed grip at neutral) generally results in more aggressive insides than outsides...the reverse of what you are experiencing.  If your initial description is accurate,  aggressive outsides and slow insides,  something unusual is to blame.

there are technical "aerodynamic" reasons why stunt ships often turn better inside than outside when flown in the "normal" counterclockwise when upright direction but it is counterintuitive that one would experience what you describe when flying in the "usual" direction.

The most likely "obvious" reason for what you describe would be the result of excessive down elevator with the flaps at neutral...which is equally "unusual".  Inasmuch as you've got the ability to adjust the flap/elevator neutral settings I would first do as you suggested; a turn or two at a time raise the elevator with the flaps at neutral and report the result.

FYI, in a lifetime of flying stunt I've had just one airplane that required such an adjustment and I've no explanation for why that was so.  I have, on the other hand, had a large number that required some down elevator at neutral flap to obtain equal turn rates with the handle set for "vertical" at level flight.

Try adjusting the elevators up a little at a atime and report back.

Ted Fancher

p.s. It's very important if you want to fly good stunt that you not let yourself believe the "relaxed" hand position at neutral is to your advantage.  Remember, you've got several options to increase handle displacement for insides: fingers, wrist, elbow and shoulder can all provide additional input for insides and all but the shoulder with ver y little need to pull the airplane toward you while doing so.  The only additional lever you've got to increase down input is what little wrist movement is left with a relaxed neutral and pulling your entire arm toward you hinged at the shoulder...a very inefficient mechanism that is all but impossible to relocate to an accurate neutral upon completion of a corner.  Doing so is not a recipe for winning expert competitions!

     Heh! I have found a few people whose grip is "relaxed" with "up" rather than down. You may remember the day in Clovis  that Al Heiger had a few problems with the Skyray, and I flew it and adjusted it to a forward tilt like I assumed. Turns out Al's "relaxed" grip was to hold in a bit of up instead of down, and he crashed it even quicker after the adjustment! He eventually got in his flights but we *ran out* of 9-4 APCs to use. That's also the day that I found out the balsa wing was vastly more durable than the original plywood - it would hit nose-first, the wings would flex forward, then back, and bounce it out of the hold back onto it's feet.

    It's almost impossible that all the airplanes could have the same misalignment, and an unusual misalignment at that. So, I expect it is something else. I would start from first principles and set the handle neutral correctly, seal the hinge lines, and then see.

      Brett
Title: Re: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 19, 2017, 12:33:01 PM
Thanks all for taking the time to help me out. I went flying today and put in about 6 flights....BTW the way, I do fly in the usual way counterclockwise upright. Anyway you guys were right about the way I hold my handle and adjust for neutral. I made certain that when resetting the elevator for neutral that my handle was perpendicular to the ground. Much better results with inside vs outside.Thanks again.
Title: Re: Outside vs.Inside turning ability
Post by: Brett Buck on April 20, 2017, 08:58:36 AM
Thanks all for taking the time to help me out. I went flying today and put in about 6 flights....BTW the way, I do fly in the usual way counterclockwise upright. Anyway you guys were right about the way I hold my handle and adjust for neutral. I made certain that when resetting the elevator for neutral that my handle was perpendicular to the ground. Much better results with inside vs outside.Thanks again.

   Happy to help. For the most part, you have a dramatic effect on what appears to be an airplane issue like "turns better one way" with very tiny neutral shifts, whether it's perpendicular or not. I make very small neutral adjustments pretty frequently, on the order of 1/64", just based on how it feels like it is turning at the time. There might be something different about the airplane, or maybe not, but it doesn't matter. If it works better, that's what it needed.

     Brett
Title: Re: Outside vs.Inside turning ability
Post by: Chuck_Smith on April 20, 2017, 04:47:48 PM
You may also be getting more line tension on the outsides - not an uncommon occurrence due to torque & p-factor . This can cause the plane to feel like it's turning better since you have more force on the controls due to the increased tension.
Title: Re: Outside vs.Inside turning ability
Post by: Joe Yau on April 21, 2017, 11:07:58 AM
Seems like every stunt plane I own turns better outside than inside....what's up with that?

Are any of the designs an inline configuration?  (motor-wing-stab)
Title: Re: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 21, 2017, 07:30:31 PM
Joe they're all different designs. I believe  that I was adjusting for neutral with a bit of down in my handle .I'll slightly readjust all of my ships so that handle is perpendicular to ground with elevators and flaps level. Thanks,PhillySkip
Title: Re: Outside vs.Inside turning ability
Post by: Ted Fancher on April 22, 2017, 09:58:11 PM
     Heh! I have found a few people whose grip is "relaxed" with "up" rather than down. You may remember the day in Clovis  that Al Heiger had a few problems with the Skyray, and I flew it and adjusted it to a forward tilt like I assumed. Turns out Al's "relaxed" grip was to hold in a bit of up instead of down, and he crashed it even quicker after the adjustment!

"Snip"

      Brett

Wow.  Gotta admit, I've never seen anybody use a "reverse relaxed" grip...assuming that means the wrist is "hinged" up with the controls at neutral.  Must have been true in Skip's case if going to a proper neutral corrected the response issue.  Make one wonder how a person would ever arrive at such a mode????   Could it have been so simple as to have been the way the handle ended up when it was attached and either the "up" line was longer than the down line or the handle cable was biased in that direction.  I could see how a new guy could hook up such a mis-matched set of lines and handle and, not yet knowing any better,  assume that was the way they were supposed to be.

When you've done this sort of thing for decades it is easy to forget that newcomers may well be led to such a situation by virtue of the goods they purchased not having proper instructions or were simply improperly adjusted and lacked proper instructions as to how to adjust them  appropriately.
Title: Re: Outside vs.Inside turning ability
Post by: Brett Buck on April 23, 2017, 12:03:01 AM
When you've done this sort of thing for decades it is easy to forget that newcomers may well be led to such a situation by virtue of the goods they purchased not having proper instructions or were simply improperly adjusted and lacked proper instructions as to how to adjust them  appropriately.

    Of course - how many times have we assisted someone who had a problem that we are mystified by, with an utterly strange cause that we would never have thought of?  And where the solution is to do something very basic?  Over the years of trying to troubleshoot over the internet, we have both had some doozies. There are a huge number of things that people like you and I know that are so ingrained that you don't even know you have them.

   An interesting example - I have had the same PIN number for the doors at work for almost 33 years now. There have been a bunch of different manufacturers, but it has always been in the layout of a telephone dial. I use it at least 20 times a day. If I had to actually tell someone what it was, I would have to find a keypad, type it in, and watch which buttons my fingers hit. I couldn't a priori tell you what it is. It's the same with all sorts of things (VAX EDT editor program "magic keys", for a computer example).

     That's why I painstakingly describe the *why* behind everything (even though it routinely attracts nitwits - see the other thread). I might not be able to envision an individual's exact issues from a word description, but if *they* understand it, they can frequently diagnose their own problems. Most of the problems people have are with really basic things that they can't envision themselves. People flying beginner or intermediate are just as smart, on average, as any expert. They lack experience but are perfectly capable of developing their knowledge, they just haven't done it yet.

     Brett
Title: Re: Outside vs.Inside turning ability
Post by: Howard Rush on April 23, 2017, 12:58:48 PM
Wow.  Gotta admit, I've never seen anybody use a "reverse relaxed" grip...assuming that means the wrist is "hinged" up with the controls at neutral. 

Tim Wescott did.  Maybe that's what wrecked his shoulder.
Title: Re: Outside vs.Inside turning ability
Post by: Tim Wescott on April 23, 2017, 01:58:30 PM
Tim Wescott did.  Maybe that's what wrecked his shoulder.

Uh, to my knowledge I tend to grip the handle with a little bit of "down" bias.  I think what whacked out my shoulder was trying to hold the handle up like Paul does -- Tom Brightbill suggested I hold it close to my chest the way Brett does, and what few chances I've had to fly since then have been promising.  You'll see it at the tuneup, if we don't get rained out.  Steve Helmick will make snarky comments about my hand flying off to the side -- that came back as soon as I stopped using a "Paul" grip, and I haven't had time to train myself out of it.
Title: Re: Outside vs.Inside turning ability
Post by: Chris Wilson on April 23, 2017, 05:25:01 PM
Seems like every stunt plane I own turns better outside than inside....what's up with that?

What is the starting position?

From upright level flight gravity can give a head start in acceleration in the outsides.

Is the phenomenon the same when flying invert?
Title: Re: Outside vs.Inside turning ability
Post by: Skip Chernoff on April 24, 2017, 05:19:42 AM
Chris I think it was the way I was setting my handle. Outsides from inverted were sharper as well. Thanks.
Title: Re: Outside vs.Inside turning ability
Post by: RandySmith on April 24, 2017, 07:18:43 AM
Wow.  Gotta admit, I've never seen anybody use a "reverse relaxed" grip...assuming that means the wrist is "hinged" up with the controls at neutral.  Must have been true in Skip's case if going to a proper neutral corrected the response issue.  Make one wonder how a person would ever arrive at such a mode????   Could it have been so simple as to have been the way the handle ended up when it was attached and either the "up" line was longer than the down line or the handle cable was biased in that direction.  I could see how a new guy could hook up such a mis-matched set of lines and handle and, not yet knowing any better,  assume that was the way they were supposed to be.

When you've done this sort of thing for decades it is easy to forget that newcomers may well be led to such a situation by virtue of the goods they purchased not having proper instructions or were simply improperly adjusted and lacked proper instructions as to how to adjust them  appropriately.

I have seen that too, on rare occasions , however there  is  more... I have seen people that would slide their hand up  or down to the inside edge of their TOO  large handle, this much extra space lets them do that, it has the same results  as  stated and you can, and will  get a better turn rate in one position, depends on which way the  hand s slid too.
I have also seen many people with  handles that have a longer down arm than the up  arm,  this will case better turn one way.
I suggest  you take a picture  of your hand  in whatever handle your using  so  we could see exactly what  your  using.
Then I would make sure you have a handle  that has independant adjustments  in  overhang, up / down bias , and line neutral  adjust

Randy
Title: Re: Outside vs.Inside turning ability
Post by: Trostle on April 28, 2017, 09:36:21 AM
One thing has not mentioned that can cause a stunt model to turn one way better than another.  I cannot explain the dynamics, but I have encountered it once with one of my models and several times when working with others that had the same problem.  First, I have to claim that I feel that I am a careful builder and take special care to make sure everything is aligned.  The first time I encountered a serious problem with a model turning better one way than the other was with a derivative of the .46 Genesis that I built in the late 70's.  I do not recall which way it turned one way better than the other, but it displayed a serious difference.  No amount of handle adjustments, elevator travel or changing the balance would correct the problem.  I kept adding elevator trim with respect to the flap neutral until I could get some semblance of turning insides and outsides the same but it came at the expense of a really poor appearance in the air when flying level with a noticeable contorted angle of attack and it did not track well in the maneuvers.  Then, I noticed that the left and right elevators were not lined up.  The trailing edges were about 3/16" off from one side to the other!  A quick twist of the elevator horn to align the elevators, removed the exaggerated elevator trim with respect to the flaps and BINGO, the airplane had equal turns and flew to the expectations of how a Genesis should perform.

As I mentioned, I have encountered this several times when helping others trim their models.  Worth a quick check. 

Keith