Quad Newbie

[p23brian]

Just purchased a Freilein Exodus from Ocean Shore Kites. I've got some experience with 2 line kites, but brand new to quads. I've watched a bunch of the online tutorials and hope to get it flying this weekend if the weather cooperates. I'm sure I'll be back here with questions!

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[Edmond Dragut]

where are you located ?

 

[makatakam]

Hi, p23brian. You'll get all the help you need right here, that's for sure.

[p23brian]

where are you located ?
 

Located east of Atlanta near Stone Mountain.



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[p23brian]

Tried flying it last weekend but there just wasn't enough wind, probably 0-3. I'd launch during a puff and fly to the top of the window. Then the puff would pass and I'd lose lift and ease back down. I did get the new lines untwisted and sorted out though. I wound them back up using the method demonstrated in one of John Barrisi's tutorials so it should be much quicker next time.


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[makatakam]

Great -- yeah the wind doesn't always cooperate. However, just being able to set up the kite without making a mess of it is a monster step in the right direction. Good job! Whichever way you go, always do it the same way until it becomes a routine that you no longer have to think about. The method JB shows in the tutorial is preferred and will never let you down. Most flyers use it with only minor modifications, if any, but like anything else in kite flying, whatever works for you is fine. JB's method is fast and easy, and when done correctly will have the kite and lines set up or broken down in under 3 minutes, without even rushing it. Just keep doing it exactly the same way each time. You can eventually modify it to suit your preferences once you have it down pat.

As far as learning to fly goes, and I know you don't want to hear this, but wait for wind that is at least half-decent. I know what inland winds can be, but fighting the wind will teach you nothing except how hard it is to fly when you're fighting the wind. Shoot for wind that is 8-12 mph, without a lot of stop and go gusts and it will be easier. If you can find an experienced flyer near you and hook up for some air time it will help very much. Learning on your own is not impossible, just a lot more difficult than it has to be. If you are within reach of any kite festivals that are coming up (drive 3 hours one way if you have to) attend them. Kite flyers are a friendly bunch, and always ready to help those who are starting out.

All else aside, get out there and fly, and keep us posted on your progress. Ask questions. We'll all do what we can to help.

Have fun, smile, and don't forget to breathe.

[p23brian]

I might have another weather window to try again today. We've got a strong front passing through and wind is 20+ right now. If it settles down to 12 or so and the rain clears I'll give it a go. I'd prefer 8-10 but we'll see. I'm a lifelong sailor so I'm pretty well tuned in to wind and weather conditions and I know my comfort zone.


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[makatakam]

Hope the weather cooperates for you.

[p23brian]

I made it out for a couple of hours but the wind was very flukey. Lots of changes in speed and direction. I did pretty well controlling the kite flying straight up to the top of the window and landing in the same spot. I also did ok flying straight back and forth across the window with 180 degree turns at either side. Still getting a feel for the controls and working on better precision. I think I've got a pretty good understanding of how tensioning the top or bottom lines changes the angle of attack for each side of the kite. But I have to work on getting the feel for applying it to making the kite do what I want. Overall a successful outing.


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[Edmond Dragut]

that is great ! a lot of practice and experimenting with the lines at different knots will give you that sweet point where you are comfortable with controls.

[makatakam]

Are you using longer leaders at the tops of the handles? The factory set-up is shorter than what most experienced flyers use, so that beginners can actually launch when the top lines are attached to the knot furthest out. Moving the top lines out (away from the handles) adds brake, squares the sail to the wind (increased angle of attack), thus putting more pressure into the sail. If at times the kite feels like it is sliding and not there, adding brake will eliminate that.

General rule of thumb: Strong winds call for more brake, giving you more control so the kite doesn't go shooting off wherever it wants to when you hit a gust. In medium to light winds you can use less brake if you wish. I use a knot or two less, depending on conditions. For very light wind, however, maximum brake is required. Maximum brake puts the most wind pressure into the sail which is what keeps in the air. No pressure in the sail, the kite falls out of the sky, unless you run backwards and create some.

If it's starting to sound like rocket science to you, don't lose any sleep over it. Once you start playing with moving the attachment point around while conditions remain the same, the effect it has on the kite will become clear. But to do that you need to have long top leaders.

Read the posts in the "pigtails" and the "leaders" posts in the "Quad Heads" topic. Once you have good basic control of the kite you will need to start the transition to longer leaders. Takako (John Barresi's wife), known as TK to everyone, makes and sells them at a very reasonable price. Once you put in the time to tie a set yourself you'll know what I mean, and you may not get them to be correctly done the first time. I tie my own, but I make and fly home-made quads which require a greater range than the Rev does. Her leaders are highly recommended, even by those who don't have them!

[p23brian]

Yes, the leaders on the top of the handles are longer than the bottom ones.  I don't know the exact lengths of the leaders, but the tops are significantly longer. They have a series of knots, allowing the larksheads to be secured in different positions.  I had them at the 2nd longest setting.

Not sounding like rocket science at all.  I am confused about the longer top leaders decreasing angle of attack though.  It seems to me that longer top leaders would position the leading edge higher if the bottom leader length is constant, which would be an increase in angle of attack.

I appreciate the pointers!

[Edmond Dragut]

longer top leaders decrease leading edge angle. advanced flyers name " the sweet point " that combinations of top and bottom knots where the kite is having the lowest leading edge angle close to 0. in that situation top and bottom lines are almost equals on launch position ( thumb up ) angle of attack is between ground and perpendicular to sky like L shape where you have 0 for attach angle on the long line. this position on launch make you to give less breaks input for kite in flying and is help you to fly in reverse much easier 

[p23brian]

The pic below illustrates my understanding of angle of attack.  If the kite was perfectly flat with the LE pointed into the wind, the angle of attack would be zero.  Raising the LE increases AoA.  

[Edmond Dragut]

using that picture like reference the sweet point is at close to < 90 degree at launch position. at 90 degree the kite is not launch that means the top and bottom lines are equals

[makatakam]

8 hours ago, p23brian said:

The pic below illustrates my understanding of angle of attack.  If the kite was perfectly flat with the LE pointed into the wind, the angle of attack would be zero.  Raising the LE increases AoA.  

True, up to 45 degrees? Once the angle of attack increases beyond a certain point the airfoil ceases to produce any lift? What about inverted flight? Now the AoA is near negative 90 degrees? The terminology is not completely interchangeable between the wing of an airplane and the sail of a kite. 

I do understand that it is technically an increase and have edited my post to read that way so it's less confusing. The complex and compound curvature of the sail does not translate well to the camber and chord of the airfoil of an airplane wing, since the kite sail simply has no camber. It is more akin to the terminology used to describe the forces at work on a sailboat sail.

[p23brian]

I think we both understand the concepts but may use different terminology.   Not to split hairs, but the sail on a sailboat (or a kite for that matter) does have camber, otherwise it wouldn't be able to generate lift. Bernoulli's Principle at work.  The air stream over the curved side of the foil covers a longer distance between the leading edge and the trailing edge than the air stream over the bottom of the foil, generating negative pressure on the curved side and producing lift.  When an aircraft is in inverted flight, the foils are just flipped over and the AoA measurement works the same as it does in level flight.  No need to get bogged down in semantics though.  I'm just trying to gain a better understanding of how all this applies when I pull on the different strings on my kite.   I appreciate the discussion!

[p23brian]

This is what the leaders that my handles came with look like. Would I benefit from longer ones on top?




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[RobB]

Those leaders look plenty long enough. Certainly longer than the stock Rev leaders. I recently switched to JB leaders, and I'm still trying to find the adjustment that I like. I got used to flying in all conditions on stock leaders for years, so the change to longer leaders will take some getting used to.

[Wayne Dowler]

Should be good for getting started, when it is time to replace - get a set of TK's. While hers may not be much longer, they usually have more knots for adjustment. You will be moving around and eventually find a knot that works best for you. Also - don't be afraid of moving the bottom "in". I find moving the bottom to almost equal moving the top by 2 knots. So you have some flexibility there.

From the pic - those look like 15" handles - good in lighter winds, a bit twitchy in heavy. 13" is the "standard length", but many of us use different lengths. I myself use 3 different sets - 13". 14". and 15". Shorter for high winds, longer for low, and middle length as my daily set. Changes the leverage you get on the sail. More a personal preference thing, but you may find those 15" to be harder to control in higher wind - IMHO.

PS: they are measured by the blank tube before bending, your set should measure around 14" tip to tip (attachment ring to attachment ring).

[p23brian]

Thanks!  I'll measure the handles and leaders and post what I find.  I appreciate the help!

[Wayne Dowler]

Had a set of TK's leaders handy - 11" long tops with 8 knots spaced at 3/4" apart. Bottoms at 3" with 4 knots at 3/8" spacing.

[makatakam]

Your leaders and handles look fine. Should be no problem in most conditions. Top leaders are long enough and in the right proportion to the lower ones. Number of and location of knots is good. If you can launch and fly with the lines attached to the knots as shown in your photo, you're doing great! There will be less to unlearn later. Compare the left and right to each other and adjust if there is more than 1/8" variance in location of the knots. Ideally, both should be identical.

The inverted reference was to the kite, not the airplane as most don't do well going backwards. I wonder if a comparison to a helicopter rotor would be more valid? Especially as it concerns variable pitch. However, that airfoil doesn't reverse and go the other way either. The problem with a kite sail is that it is a reactively variable airfoil. It is controlled by changing/warping the airfoil to achieve changes in speed and direction, like the early Wright brothers' flyers.

If you stand directly below the kite as someone else flies it, you will be surprised by the amount of shape-shifting the sail goes through.

[p23brian]

At risk of taking this thread a little far out into the weeds...

Helicopter rotors work pretty much the same way as any other airfoil.  The pilot uses the cyclic stick to change the pitch (AoA) of the blades to increase or decrease lift.  It gets complicated when the helo is moving forward.  As the rotor blades spin, on one side the blades are moving toward the front of the aircraft.  As the continue around the other side they are moving towards the back.  The wind that the blades "feel" (apparent wind) is the sum of the speed of the spinning rotor blade and the speed of the aircraft moving forward.  if the blades are spinning at 100 mph and the helo is moving forward at 100 mph, the blade on one side feels 200 mph of wind.  On the other side of the aircraft where the blades are heading toward the back, the blades feel the 100 mph of the aircraft's forward motion MINUS the 100 mph the blade is moving in the opposite direction, or zero wind.  This causes the blades on this side to lose lift.  This limits the maximum airspeed at which a helo can fly.

In the case of a quad kite, by manipulating the controls you could (I couldn't ) tension the lower lines and ease the upper ones causing the leading edge to become the trailing edge and vice versa.  If the kite were flipped around so the leading edge (with the rod in it) was toward the ground and you were flying the kite toward the top of the window this would be the case.  The "leading edge" would be the bottom of the kite.  Same angle of attack principles would apply.  I'm using the term "leading edge" for the edge of the kite closest to the direction the wind is coming from.  I know it's common to use the same term for the edge of the kite with the rod in it regardless of orientation to the wind.

[John Barresi]

Me thinks @cyclic might like to get in on this topic as well, another avid helicopter / kite enthusiast.