Active Bridle Systems (ALL)

[JoneZ]

Im reading up on different types of active bridles (the dihedral worked great btw), and I want to try a Cross Active as explained here -- http://www.wardley.org/kites/bridle/xactive.html -- but I am not sure if I need to alter my inner leg.

Is there a general rule of thumb on measuring these lines? I know in a dynamic setup there is a 90o rule for the upper and outer, and a target zone for the inner leg, to get ur tow point to a desired location. Should I just line it up so that after my cross active bridle is set, the tow point lines up to exactly where it did on the factory set static bridle?

Does this make sense? lol

Thanks for the help

~JoneZ

[JoneZ]

Also, Im wondering about the infamous "sheet bend", and how you keep it from slacking once the bridle is pulled tight (ie. the loop you made on your bridle that the sheet bend wraps around pulls straight as tension is introduced to the lines)?

I found my measurements of line, and thats really hindering the exact length, as the bend pulls loos and once re-tightened, its either a little longer, or a little shorter.

I just ended up re-measuring and tied a single overhand knot right above the sheet bend.

Oh!!! Also, lol. (inquisitive this morn.), being as this is an "active" setup, Im assuming that the pitch activators should remain free to move, since the cross activator keeps a small amount of tension between both pitch activators. Right?

I ran into that same problem with the Dihedral setup I had. I would adjust my activators, then fly, then land, and they would be all out of whack. I naturally thought that since its an "Active" system, that they should be moving around as the wind increases/decreases,, but it still just didnt seem right, since I was using a totally different knot method than the cross active (was using a triple wrap slip knot).

Are both the Sheet bend, and triple wrap slip knot equivalent? Or is there a difference.

Thanks in adv.

~Jon

[JoneZ]

Yeah, I went to Delta Park yesterday and tried the Cross-active bridle out. For all intents and purposes it flew well (I think), but I had to keep readjusting my activators (both pitch and cross), because they would slide during flight. I would think this is ok during flight, but they slid into a bias position (ie: one side closer to the tow point than the other side of activator), which makes me think (especially in the case of the pitch activator) that its drastically changing my flight characteristics, and Im just not noticing it, because its in mid-flight.

Are these knots (the sheet bend) suppose to be that free moving (I can tighten them good-n-tight, but after 5mins of flight they are loose again, and sliding all over the place)? If not, Im assuming I should use another knot (like a Prussik) thats a little tighter? The Sheet bend is a loose knot and doesnt stay tight (Im assuming its got to do with the fact that it is flight line instead of actual bridle line).

[JoneZ]

Cross Active bridles allow (Im reading) for your tow points to be set further to the outer edge, while not sacrificing trackability.

Heres where my tow point sits right now with the setup. (the lines arent exactly tight, but its a good approximation)

Does everything look kosher?

The yellow lines I drew are the bridle itself (not including the yoke that is my tow point), the green lines are my pitch activators, and the red is my cross activator.

The tow point sits where the yellow lines meet up (obviously. lol)

Heres the lengths of my lines respectively:

Outer Leg (x2) = 42.5 inches total: (upper is 19" and outer is 23")

Inner Leg (x2) = 23 inches

Pitch Activator (x2) = 7.5 inches

Cross Activator (x2) = 19 1/4 inches

Im not noticing any tracking issues, but I am noticing it a little hard to slide, but that could just as easily be pilot error.

What would I notice if my tow points go too far out toward the outer edge? Reason Im asking, is to be able to tune this bridle setup accurately.

Thanks (once again) in advance. lol

~Jon

[roisinroisin21]

Hi Re tow points inhauls and out hauls.

Try wrapping the bridle legs around the lower spreader apa fittings 1 wrap 2 wrap 3 wrap & so on , see what happens

The kite will turn tighter and tighter until tracking and control is lost and down she`ll come to far

Try it , i have 2 turns on the quantum and 1 on a sweety , works for me but then you can also undo it and return

[JoneZ]

So your talking about wrapping the outer and inner legs around the spreader, or just the outer?

Yet, another Q. lol

On the cross active setup, should my inner legs be longer, thus pushing my towpoint to a wider setting? Im thinking thats maybe the case, as when you are turning, the tow points can float to a wider setting making turns sharper, but also can be pulled in (by the cross activator) when flying in a straight line.

Am I close here?

Thanks.

~Jon

[roisinroisin21]

Just the outer , which should move the tow points towards the Lle and wrapped round the Lle apa fitting

You`ve some serious q`s there mate

[JoneZ]

hehe, indeed. Im just trying to understand better, what I'll feel as I make these settings more pronounced, as opposed to inactive.

I unhooked everything, and flew with a 3 point setup, re-tuned it. flies awesome. So I hooked on some dynamic yokes I made, tried it out. NO GOOD!! Too squirrelly, so I switched back to 3 point, came home, and measured out some more spectra line to re-do my cross active setup. I shortened the pitch activators a little, and lengthened the cross activator a little. I did this because I was noticing too much of an active effect. I think it was due to my pitch activators being too far from my tow point, and squeezing my uper and inner legs too much. It was really "rocky" if you know what I mean. So I hooked the new lines up, and went out yesterday to test fly it -- introducing the x-active setup gradually.

I still have some fine tuning to work on, but man,, I think the x-active setup is the way for me right now. Sliding and flipping the kite is much more responsive. Pulled off my first REAL yoyo yesterday (without a tail-weight = much more running forward to wrap the lines)-- yoyo to fade, tended it, and managed to actually turn the kite to a fly-able position, unwrap and fly off.

I Love my Widow.

[roisinroisin21]

Man you`re in the bridle DEEP

Good to hear you got the roll up and out. I got my first 3 roll ups today and roll out fantastic fealling , shame i was on my own Huh

Keep the reports coming in "Luv em"

Ps don`t ask me any DEEP q`s i aint got the answers I`m to young to have all the answers Hahahahahahahaha

[Big Easy]

Im reading up on different types of active bridles (the dihedral worked great btw), and I want to try a Cross Active as explained here -- http://www.wardley.org/kites/bridle/xactive.html -- but I am not sure if I need to alter my inner leg.

Is there a general rule of thumb on measuring these lines? I know in a dynamic setup there is a 90o rule for the upper and outer, and a target zone for the inner leg, to get ur tow point to a desired location. Should I just line it up so that after my cross active bridle is set, the tow point lines up to exactly where it did on the factory set static bridle?

Does this make sense? lol

Thanks for the help

~JoneZ

Hi All,

My first post on this forum. FWIW, kite/bridle design is always going to be active even if it's just a simple three point bridle. What complicates the issue of bridle design is that a stunt kite is constantly changing the angle of attack. For every change in forward speed and every change of altitude the angle of the apparent wind changes even if the wind speed is constant. When the angle of attack changes, so does the center of effort exerted on the sail. If all things were constant, wind speed, forward speed and altitude then the center of effort will not change position. Then you could design a tripod bridle with the tow points directly over the center of effort on each wing then everything would be cool.

On most kites, as the angle of attack increases the C of E move inboard. If it is enough to cause the spine to be deflected back or the lower spreaders to bow back then the tow points are going to dynamically move inboard as equilibrium will try to be established. I've never experimented with a cross active bridle, but i would imagine that if it not done correctly for your particular kite then when the tow points move inboard the cross bridleing would be rendered useless as it would go slack. All of this is just to say, I thinks that bridles need to be designed for each particular kite. So experiment with different angles and lengths 'til you get it right.

When I first experimented with bridles about 1988 (yes, I am old school) I flew my test kite with a bridle that was 100' long. With five lines running to my handles I could learn the dynamics of a flying stunt kite by making minute adjustments right at the handles. Very impractical, but I learned a lot. In another test I attached a carbon rod between the tow points in order to fix them in place. Sloppy, but I learned something again.

Kite design is always going to be a compromise because off the dynamics involved. The perfect kite would work in synergy with it's bridle so that for every change in angle of attack, the bridle configuration would change in a way that would optimize the kites performance at that particular moment.

Most Excellent Regards,

Ray