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Kites! Kites! Kites! => Sport Kites => Topic started by: Spz0 on May 28, 2009, 08:36 AM



Title: Bridle Modification
Post by: Spz0 on May 28, 2009, 08:36 AM
Could someone describe for me, the changes in flight when you lengthen or shorten your bridle lines, as a whole, and in specific (inhaul, lower outhaul, upper outhaul).
I would love to understand this more.
Im thinking of messing around with my Widow's bridle, to try and curb some oversteering issues I have with it.
I've already got the factory standard measurements for it, and was thinking of shortening all of my bridle legs by 1", and installing pigtails on my LE at the lower outhaul, and spine section for the inhaul -- with 3 or 4 overhand knots at 1/2" intervals.

Any help would be immensely appreciated.  :)

~Jon


Title: Re: Bridle Modification
Post by: anOldMan on May 28, 2009, 10:23 AM
If you really want to do this you can start Here - http://www.andywardley.com/kites/bridle/index.html (http://www.andywardley.com/kites/bridle/index.html)

For the basics on kites and bridles go here - http://www.ian.ourshack.org/kitedesign/index.html (http://www.ian.ourshack.org/kitedesign/index.html)

And you can always spend hours with the links from here - http://www.gwtwforum.com/index.php?topic=105.0 (http://www.gwtwforum.com/index.php?topic=105.0)

Best hunting. :) ;) :)



Title: Re: Bridle Modification
Post by: CTaylor on May 28, 2009, 10:37 AM
There's a few things that can cause oversteer in a kite.

1.  Too much tail weight.  If you're flying a mostly stock kite and like the weight for backflips/yoyo's and such move on to 2 or 3.

2.  Tow point is set low on the kite.  Most kites are adjustable in this aspect so you can try moving the bridle tow point up and see if that remedies the problem.

3.  Tow points are too close together.  This is common on some kites.  It's really a matter of personal preference for the feel of the kite.  If you are heavy handed or like larger arm movements you can lengthen your inhaul bridle lines.  That should give you more arm movement and lessen the amount of oversteer.  This will have the largest effects on other aspects of the kite.  In some cases it will make the fade harder or easier to lock in.  It will also effect other tricks.

Changing the bridle on a kite can go a long way to making the kite feel better or worse in your hands.  I'd suggest you have some way to configure the kite back exactly the way it was originally so you have something to work from.  Take measurements of everything and write them down.  Then make your changes that you want to try.  If it doesn't improve the kite's feel you are always able to move it back.

I personally "try" not to change kites much anymore.  The designer built it with their feel/preference in mind.  Changing your technique can make it fly like you want.  Although, some kites you'll just never click with.


Title: Re: Bridle Modification
Post by: Gardner on May 28, 2009, 11:13 AM
Hi CTaylor,

In some cases, not all, lengthening the inhaul and/or shortening the outhaul will cure oversteer :). To find the right combination is a matter of trial and error a quarter of an inch at a time >:(.  A  word of caution, don't do both bridle legs at the same time :'(.  Maybe shortening the outhaul will work the first time; maybe an outhaul adjustment will work

The amount of oversteer also depends on what the kite was built to to preform.  A kite built for tricks will never have the precision of a freestyle kite and a freestyle will never be as precise as a ballet kite.

If there are experienced kite flyers in your area, ask them to give you a hand.
Most will be willing to help.

Gardner


Title: Re: Bridle Modification
Post by: fidelio on May 28, 2009, 02:24 PM
maybe we could talk randyg into making a tutorial which contains some 'general rules' about bridle modification. as in lengthen this leg, expect this. shorten this leg, this happens, etc.

he's a great candidate because he's very knowledgeable, has the experience necessary, is great at making tutorials we can all understand, has the video flying, filming and editing skills, and i happen to know his bridles are already setup for easy changes in length of individual legs. plus he's just a really friendly guy who's willing to help, who shares the passion.

the only problem is he's pretty busy and might not have the time.

he REALLY knows how to tune a kite  8) and imo such a video would be a great addition to the fantastic set he's already created.


Title: Re: Bridle Modification
Post by: Spz0 on May 28, 2009, 02:28 PM
Thanks for all the info ppl  :)
I 'do' have the default measurements for my bridle, so I think Im going to go ahead and make pigtail adjustments for the inhaul and lower outhaul lines (as I already have a pigtail adjuster on the upper outhaul for wind adjustment).
I was out today gettin use to the Widow (the wind hasn't been up enough for her to fly).  I ended up shortening the inhauls by 1/4" (by tying an extra overhand knot at the base of the larkshead attached to the spine).
I did this with the following in mind:
Plain and simple, the Widow flies better with the lines crossed over eachother once or twice.  What that is telling me (by deductive reasoning -- tell me if Im wrong here) is that my inhauls need to be pulled in a little.   When the lines are crossed over, its naturally pulling the bridle in and down a little, right?
That being said, thats the reason I tied off the inhauls by 1/4".   I also lowered the upper outhaul by 1/2" (I have pigtails on the upper L.E. fittings for wind adjustment).
Seems to be flying a little more straight and narrow now, although with the towpoint lowered, its a little resistant to launching.
Im thinking maybe I should in turn, move the tow points up a bit to compensate?  
Talk about trial and error.  heh

I use to have a cross active setup on my Widow, but I took it off.  Having my upper outhaul pulled in like it was (even though it was only a little) was nerfing my kite all together in flight.  Too much rocking too and frow.  After that I tried pulling in only my inhaul, by attaching a line from the inhaul to my upper L.E. fittings -- pulling the line in only a little.  To be honest, I couldnt notice any difference,, although the winds were a bit high.  I've seen that setup on other kites, but do not know what it is called, nor do I know the benefits of it.

umm,,, discuss?    hehe  ;)


Title: Re: Bridle Modification
Post by: Spz0 on May 28, 2009, 02:28 PM
maybe we could talk randyg into making a tutorial which contains some 'general rules' about bridle modification. as in lengthen this leg, expect this. shorten this leg, this happens, etc.

he's a great candidate because he's very knowledgeable, has the experience necessary, is great at making tutorials we can all understand, has the video flying, filming and editing skills, and i happen to know his bridles are already setup for easy changes in length of individual legs. plus he's just a really friendly guy who's willing to help, who shares the passion.

the only problem is he's pretty busy and might not have the time.

he REALLY knows how to tune a kite  8) and imo such a video would be a great addition to the fantastic set he's already created.


Agreed  :)  Randy is indeed the man


Title: Re: Bridle Modification
Post by: DaveH on May 28, 2009, 02:33 PM
Spzo,
I have a lot of time on the Widow. If I may, try taking the weight out.  I fly mine without weight and still get really really tight rollups, but with much less oversteer. Backspins are lots easier too, because the kite is more stable in pitch.   Just a thought... ;)


Title: Re: Bridle Modification
Post by: Spz0 on May 28, 2009, 02:35 PM
aye, I have the weight out on that sucker already.  Even took the little plastic ferrule cover off.

I think I may be just expecting too much out of her.   Or maybe its the inexperience flowing out through the lines, and into the Widow :o


Title: Re: Bridle Modification
Post by: Spz0 on May 28, 2009, 03:19 PM
Thanks for all the info ppl  :)
I 'do' have the default measurements for my bridle, so I think Im going to go ahead and make pigtail adjustments for the inhaul and lower outhaul lines (as I already have a pigtail adjuster on the upper outhaul for wind adjustment).
I was out today gettin use to the Widow (the wind hasn't been up enough for her to fly).  I ended up shortening the inhauls by 1/4" (by tying an extra overhand knot at the base of the larkshead attached to the spine).
I did this with the following in mind:
Plain and simple, the Widow flies better with the lines crossed over eachother once or twice.  What that is telling me (by deductive reasoning -- tell me if Im wrong here) is that my inhauls need to be pulled in a little.   When the lines are crossed over, its naturally pulling the bridle in and down a little, right?
That being said, thats the reason I tied off the inhauls by 1/4".   I also lowered the upper outhaul by 1/2" (I have pigtails on the upper L.E. fittings for wind adjustment).
Seems to be flying a little more straight and narrow now, although with the towpoint lowered, its a little resistant to launching.
Im thinking maybe I should in turn, move the tow points up a bit to compensate?  
Talk about trial and error.  heh

I use to have a cross active setup on my Widow, but I took it off.  Having my upper outhaul pulled in like it was (even though it was only a little) was nerfing my kite all together in flight.  Too much rocking too and frow.  After that I tried pulling in only my inhaul, by attaching a line from the inhaul to my upper L.E. fittings -- pulling the line in only a little.  To be honest, I couldnt notice any difference,, although the winds were a bit high.  I've seen that setup on other kites, but do not know what it is called, nor do I know the benefits of it.

umm,,, discuss?    hehe  ;)

I need to really stress that prior finding, that the kite just flies better with the lines crossed.  When the lines are arent crossed over, there's a noticeable difference in control.


Title: Re: Bridle Modification
Post by: mikenchico on May 28, 2009, 03:41 PM
My opinion on the Widows oversteer is weight, the Widow Maker doesn't really suffer from it, the Widow does, especially in light winds. Since the kites are identical in sail shape and you've corrected the bridle (some early production models had bridle problems) and still find the oversteer to be objectionable you might try reducing some weight. The Widows P300 frame is 14 grams heavier then the Widow Makers Nitro frame. I don't know what would happen to the kites response & handling if you swapped out the lower leading edges and even the spreaders for P200's but if you fly mostly in low winds it might be another option to look at if you have some spare rods about.



Title: Re: Bridle Modification
Post by: Spz0 on May 28, 2009, 03:53 PM
hehe, that is essentially my next step. I've already swapped out the lower spreaders with P200's and the solid ferrule with a hollow core ferrule, and next Im going to swap the leading edges.  P300s are 2 grams heavier than the P200s.  The ferrules used are also solid core, which are 2 grams heavier than the hollow core.  Replace those with hollow core and I save another 4 grams per side (including the nock end ferrules).  So, with the spreaders and the leading edge upgraded to P200s, I will shed almost an ounce.  22grams by my count.

I was thinking about the whole pendulum theory with the oversteer factor on the widow.  Good to hear someone else is as well.  lol


Title: Re: Bridle Modification
Post by: ET on May 28, 2009, 04:36 PM
My opinion on the Widows oversteer is weight, the Widow Maker doesn't really suffer from it, the Widow does, especially in light winds. Since the kites are identical in sail shape and you've corrected the bridle (some early production models had bridle problems) and still find the oversteer to be objectionable you might try reducing some weight. The Widows P300 frame is 14 grams heavier then the Widow Makers Nitro frame. I don't know what would happen to the kites response & handling if you swapped out the lower leading edges and even the spreaders for P200's but if you fly mostly in low winds it might be another option to look at if you have some spare rods about.



Agree.

Also might change out those end nocks and ferrules.  Those suckers are heavy...   


Title: Re: Bridle Modification
Post by: Spz0 on May 28, 2009, 09:08 PM
Agree.

Also might change out those end nocks and ferrules.  Those suckers are heavy...   

2x agreed
at least 2 grams heavier than hollow ferrules and nocks by my count.


Title: Re: Bridle Modification
Post by: Allen Carter on May 29, 2009, 03:12 AM

Plain and simple, the Widow flies better with the lines crossed over eachother once or twice.  What that is telling me (by deductive reasoning -- tell me if Im wrong here) is that my inhauls need to be pulled in a little.   When the lines are crossed over, its naturally pulling the bridle in and down a little, right?

You're wrong.
 
:)


In flight each leg of the bridle is pulled tight. The tow point pigtails get pulled a tiny bit towards each other when the lines are wrapped, but the geometry of the bridle doesn't change.

I don't know if you have any other fliers in your area, but I've always found it helpful to put a troubled kite into someone else's hands for an opinion. I've had experienced flyers make an intuitive adjustment or two that had been eluding me, or just show me that the kite is really OK by flying it a bit.

Have fun with the bridle mods. It's certainly more art than science. It can really suck up perfectly good flying time, but if you're in it for the long haul it's useful knowledge.





Title: Re: Bridle Modification
Post by: Spz0 on May 29, 2009, 08:20 AM
In flight each leg of the bridle is pulled tight. The tow point pigtails get pulled a tiny bit towards each other when the lines are wrapped, but the geometry of the bridle doesn't change.

Even in a dynamic (turbo) bridle setup? 
Im not contesting, Im just trying to understand this more.  ;)


Title: Re: Bridle Modification
Post by: Spz0 on May 29, 2009, 12:55 PM
hehe, that is essentially my next step. I've already swapped out the lower spreaders with P200's and the solid ferrule with a hollow core ferrule, and next Im going to swap the leading edges.  P300s are 2 grams heavier than the P200s.  The ferrules used are also solid core, which are 2 grams heavier than the hollow core.  Replace those with hollow core and I save another 4 grams per side (including the nock end ferrules).  So, with the spreaders and the leading edge upgraded to P200s, I will shed almost an ounce.  22grams by my count.

I was thinking about the whole pendulum theory with the oversteer factor on the widow.  Good to hear someone else is as well.  lol
My opinion on the Widows oversteer is weight, the Widow Maker doesn't really suffer from it, the Widow does, especially in light winds. Since the kites are identical in sail shape and you've corrected the bridle (some early production models had bridle problems) and still find the oversteer to be objectionable you might try reducing some weight. The Widows P300 frame is 14 grams heavier then the Widow Makers Nitro frame. I don't know what would happen to the kites response & handling if you swapped out the lower leading edges and even the spreaders for P200's but if you fly mostly in low winds it might be another option to look at if you have some spare rods about.



Agree.

Also might change out those end nocks and ferrules.  Those suckers are heavy...   

Just replaced the nock ends and ferrules.

I weighed them just for kicks,, and the stock nock ends with the ferrules and line attached were 4 grams each side.
The new nock ends and hollowed ferrules I replaced them with (with shorter, lighter weight line) are now 1.5 grams per side.
2.5 grams in weight reduction per side.
That might make a slight difference, being as all that weight is in the last 3 inches of the wingtip.
I'll post when I fly her next.

-cheers
~Jon


Title: Re: Bridle Modification
Post by: anOldMan on May 29, 2009, 01:52 PM
Spz0,
Allen is correct. You are thinking that the kite is a static entity in the air. It is not. When the kite is flying, it is a dynamic entity. There is pressure on all bridle lines. (except of course during slack line movements). So you should be looking at the tow points only and not the tow line. Even with a turbo bridle the dynamic tow point and pressure on all lines is true.

I don't know the length of line that you are using but unless it is 5 meters or less there is very little difference in the angle of the line to the tow point from a rapped line and an unwrapped line.

The rap will always be closer to the person flying the kite than to the kite. To verify this, put 3 or 4 raps in your line. Put your hands in your neutral position and fly the kite to the top of the wind window. Look at when the rap is positioned. Now do the same thing but put you hands together in front of you. The line rap will be closer to you. I order to have the rap closer to the kite (and then have some effect on the placement of the tow point), you would have to have your hands about 8 meters apart.

The difference in flight characteristics that you feel is probable due more to the timing between when you input  (pop a line) to the kite and when the kite reacts. With a rap there is always a small delay unless you have 100 % no friction between the lines. That is why sport kiters want very slippery lines. You do not want to change your input depending on the number raps you have on you line.

The only trick I can think of that you would want a rap of your lines as not have the rap is a Yo-Yo. And that is to have a higher percent of have both lines catch the Yo-Yo stoppers.

Just out of curiosity, what are you going the call your kite when you are finished with the modifications. It is going to be Widow in sail design only.

Good winds (and you are going to need them to test all these modifications.) That said, you will probable know more about the Widow than anyone but the designer.


Title: Re: Bridle Modification
Post by: Spz0 on May 30, 2009, 06:21 PM
It'll still be a widow my friend.  I think I'll name it -- Widow "Voided Warranty Edition".

K, so I just snapped one of those hollow core ferrules today.  The ferrule that connects the lower spreaders together?   Yeah.  Shredded it.  so, out the door go my new P200 lower spreaders (the right side spar fractured right where the snap occurred).
I Love throwing away money.. Really!  I do!  :-[
I'm pretty sure theres no strength difference from P300 to P200, but those ferrules....
Now Im wondering if it is a good idea (when I reframe the leading edge) to use hollow core ferrules to connect the LE spars?
Probably not I would assume.  It wouldnt be going through quite as much stress as the Center T does, but there is always tension and flexing happening on those LE's.

Is there such thing as a solid core lightweight ferrule?


`Jon


Title: Re: Bridle Modification
Post by: Allen Carter on May 30, 2009, 07:08 PM
Hollow core ferrules (really just hunks of pultruded rod) are usually OK on SUL frames, but I wouldn't use 'em in UL or heavier frames. I don't know if the various brands (2 or 3?) of solid ferrules I've used vary in weight. I just want a ferrule to be strong.


Title: Re: Bridle Modification
Post by: Spz0 on May 30, 2009, 07:23 PM
Agreed.   I think Im in the trial and error stage of kiting and modifications.
Just sucks I blew $20 on these spars to have them break in 15Mph winds.



Title: Re: Bridle Modification
Post by: Allen Carter on May 30, 2009, 07:40 PM
What kind of spars?


Title: Re: Bridle Modification
Post by: Spz0 on May 30, 2009, 08:34 PM
Skyshark II P200's.

They fractured right at the ends where the ferrule that was inserted snapped.


Title: Re: Bridle Modification
Post by: Gardner on May 30, 2009, 09:50 PM
i'm not surprised the rods snapped.  In a 15 mph wind, there was just too much stress.

You are learning the hard way what many veterans already know -- once the limitation of the rod is exceeded expect disaster :(.  Even an Aerostuff hollow ferrule will break if overstressed :-[.  And that one short little ferrule costs just a tad more than than two SS tubes.  I know because I did it.

BTW, that Aerostuff  ferrule is only about five or six inches long :'( :(.

Before someone asks,"Don't you believe a design can be improved by tweaking or tinkering?", I'll answer,"{ Yes, it can."  There are any number of successful designs which have been improved over the years by tinkering and tweaking.
However, there is also a lot of "been there and done that experimenting" knowledge out there which is available for the asking.

I believe almost everyone in this forum will share their knowledge if asked.  A number have responded to my questions and the advice given was good.  There are times I have even tested it to be certain I was wrong. :'(

To answer your question about a lightweight solid ferrule, yes there is -- a carbon (graphite) ferrule as opposed to a fiberglass ferrule.

Good luck with your experiments.  After all the P-51 Mustang would never have been  the best fighter plane of WWI if someone hadn't thought of swapping its original engine out for a Rolls-Royce Merlin.

Gardner




Title: Re: Bridle Modification
Post by: Allen Carter on May 31, 2009, 12:22 AM
Both broke at the same time? At the T? That's odd. P200s are damn strong. 15 should be no problem if the frame is set up right.

It's common to have issues with the spreaders "spreading" off the ferrule. If you have less than an inch or so of ferrule in the spreader, the end of the spreader will split. There are a number of things you can do to make sure the spreaders say put. Longer ferrule. 3.5" minimum. 4" is better. On a lot of kites just angling the standoffs in towards the T even a little bit will do the trick. Standoff/spreader fittings need to be tight or stoppered. My favorite Ts capture the spreaders with friction. Some kites need a rubber band to pull the spreaders together.

Maybe take a look at how it's done on the Skyburner version.

Anyway, with a proper T setup, P200s will do fine beyond 20MPH.



Title: Re: Bridle Modification
Post by: Spz0 on May 31, 2009, 08:56 AM
Thats what I thought as well.  I had a 3.5" ferrule glued in on spreader - inserted through the center T fitting (rubber) then the other spreader was inserted to the ferrule (if ya get me).  So there was 1.5" of the ferrule in each side, and 1/2" in the center T fitting.  The snap occurred on the 'non glued' side, fracturing the spar right at the end of the spreader -- where the ferrule snapped.  The fracture is about 1 1/2" long down that spar.  The other spar (with the ferrule glued into it) didn't actually fracture.  It just looks like it (a scratch).   I am not able to get the fragmented ferrule out of that spar, as theres only fragments sticking out of the end.  I'd still use it, but the balance would be off center from the remainder of that ferrule still glued in.


Title: Re: Bridle Modification
Post by: Spz0 on May 31, 2009, 09:01 AM
Heres a couple pics.
Note the 2nd pic.  Thats the fracture Im talking about.

(http://img20.imageshack.us/img20/2341/imgp0977.jpg)

(http://img269.imageshack.us/img269/2329/imgp09782.jpg)


Title: Re: Bridle Modification
Post by: stapp59 on May 31, 2009, 09:57 AM
If you have a 1/8 to 3/16 piece of music wire 36" long, you can carefully heat the end of the P200 with the broken ferrule using a propane torch to soften the glue.  Then use the music wire to pop out the broken ferrule.  Have done this several times successfully.  You can also wrap the last inch or so of the the non ferruled P200 end with spectra line and glue to resist splitting.

Do use solid ferrules exclusively except with P90 and 2PTs where hollow is OK.  The hollow ferrules break pretty easy as you know  :-\

Steve


Title: Re: Bridle Modification
Post by: Spz0 on May 31, 2009, 10:14 AM
If you have a 1/8 to 3/16 piece of music wire 36" long, you can carefully heat the end of the P200 with the broken ferrule using a propane torch to soften the glue.  Then use the music wire to pop out the broken ferrule.  Have done this several times successfully.  You can also wrap the last inch or so of the the non ferruled P200 end with spectra line and glue to resist splitting.

Do use solid ferrules exclusively except with P90 and 2PTs were hollow is OK.  The hollow ferrules break pretty easy as you know  :-\

Steve

Thanks so much bro.  :)   Got the ferule out with no problem.  :)   I just used a lighter, using only the blue flame to heat the spar.  Worked like a charm.  Thanks again!

That trick with wrapping spectra around the spar -- is that to patch the one that is split?  Or is that more of a preventative maintenance thing?

-cheers
~Jon


Title: Re: Bridle Modification
Post by: stapp59 on May 31, 2009, 10:25 AM

Thanks so much bro.  :)   Got the ferule out with no problem.  :)   I just used a lighter, using only the blue flame to heat the spar.  Worked like a charm.  Thanks again!

That trick with wrapping spectra around the spar -- is that to patch the one that is split?  Or is that more of a preventative maintenance thing?

-cheers
~Jon


I've done both patching and prev maint using wrapped spectra, glue (CA or epoxy), and a little black enamel paint to hide the mess.  Depending on the length and depth of the split, it may just be better to replace the tube than risk another in flight failure. 


Title: Re: Bridle Modification
Post by: Spz0 on May 31, 2009, 10:29 AM
Thats what Im thinkin m8.

Oh!  Just a weird piece of info:
The Premier Widow's spec'd out to be framed with P300 SS spars. 
I just took the leading edges out (to see if I could use the spars I have to reframe the lower leading edge), and they're P200's.
So, the only spars that are P300's are the spine, and the lower leading edges (upper spreader is P200).
Maybe they ran out of the P300's in the Chinese shop where mine was made.  lol

-cheers
~Jon


Title: Re: Bridle Modification
Post by: stapp59 on May 31, 2009, 10:52 AM
Interesting on the tube selection.  I don't have a Premier Widow but as Allen says, the P200 is a pretty tuff tube and should be ok as a LE or LS in winds up to 15mph. A P300 spine, P200 LE, and 5PT or P200 LS is pretty common framing for a std.

The heavier tubes are great for adding momentum to tricks but will contribute to oversteer as will lots of tail weight.

Balance and stiffness are other factors to consider when selecting framing. Lot's of trial and error here.

I know the Widow Maker is framed in SS Nitro tubes which weigh the same as P200s but are stiffer.

To summarize this thread, try moving the bridle up and out a little, reduce tail weight, and reduce weight at the extremities to tame the oversteer.

Don't forget that technique may help compensate for oversteer as well.  ;)

Good luck...

Steve


Title: Re: Bridle Modification
Post by: Spz0 on May 31, 2009, 11:21 AM
Thanks for the advice.
The Widow has those adjustable pigtails on the upper outhaul, attached to the upper LE fittings.  I'm going to experiment with bringing the nose forward by moving the upper outhaul as close to the fitting as possible on the pigtails, then lowering the tow point.
I want to lower the tow point because, with the upper outhaul all the way forward, theres a lot of rocking back and forth from the nose.  Other than that, it does track much better, but its a little harder to pancake.
So Im hoping that by moving the towpoint down bit by bit, I'll be able to find a happy medium.  :) 
I'll post the results.

-cheers
~Jon