APEX III - what's wrong with the depower?

Hey Beamer, was that 54mph? Nice! I like it near the end, kite, road, kite, road

R-ling, listen to all of those guys. I have an Apex III 10m and I am learning also and had the same problem. You can also mess with the trim strap while you are practicing and see what it does for you as well. I put a cheesy video of me and my friend learning on my kite and you will see how it back stalls and I tell him to let out the bar http://vimeo.com/57469436 .

Well, I will keep it alive by commenting on my Apex III 10M I flew again yesterday, in below 0 temps

Long story short I used the trim strap to increase(?) the AoA, pulled it in (which is depower I guess because you are actually removing the slack in the brake lines because you are pulling in the power lines). Because of this I thought the kite was flying with something wrong in the bridle because it looked like the brakes were constantly under tension. Well, duh!:dunno: Of course they were under tension, because I pulled in the trim strap. When I started flying it with some de-power bar applied it started flying how I remember it flying without the trim strap pulled in.

I didn't keep it short but I wanted to point out my stupidity and what I learned.

If you fly with the trim strap all of the way out it will start flying best with the bar all of the way out.*
When you trim in, don't forget to bring in the bar the same amount or you will be flying with the parking brake on

Oh, and if you fly on a frozen lake with no snow, get an ice screw! Crap is that annoying when you are trying to figure out a tangle and everything is sliding around

*I'm quite a noob so there are caveats to all of this and I am aware of that.

Finally got a decent tryout with the Apex III (7.5) in good wind (up to 20 knots), it was almost too much to handle. I have now the middle lines connectet to the 2nd knot. Works best. I tried the inner knots, but then the kite was very difficult to turn, so I moved it out to the 2nd again. But still the kite gives a pretty hard pull with the bar all the way out. But when crusing down the lake, this is kind'a neat, relaxes the arms for a while. all in all, this is a great kite

I guess if we want to keep it going, something else I have found is the depower-stopper ball. When I was out on the ice I had my sheeting strap all of the way out so when my bar was all of the way out the kite flew great. It is also easy to "park-and-ride" like this because you can use one hand on the middle of the bar to keep the kite flying straight. No pulling, you can keep your torso facing forward, etc.. However, when I sheeted in 50% I couldn't get the kite to fly as well unless I pulled the bar in, which made it hard to fly one-handed. That is also when I figured out that when you sheet-in you also need to bring the bar in or there may be constant brakes being applied (I still haven't confirmed this. Someone said that the brakes should be MORE slack because you are bring the kite closer to you. But that is for a different post). Well, that is when I figured out that I should move the stopper ball down so I can have the depower bar at the right spot and park-and-ride again.

I have also found out that in gusty winds it can be a PITA to solo set up the kite. I am sure this can be true with all foils, as the bridle likes to wrap the wing tip(s). Then, when you try to launch it is a mess. I use an ice screw with the brakes applied but the shifting wind can bounce it around and wrap itself up. I think next time I need to pile snow on it once I confirm everything looks good.

Another flying tip I have found is that for a really tight turn just reach up and pull the brake line corresponding to the direction you want to turn

next time your on the interstate roll your winda down and put your hand out............lay your hand flat allowing air to pass equally owner the top and bottom of your hand..............this is bar out.........now raise your fingertips......feel the air slow down put create power and lift............this equals bar in.....

remember this as your flying...........

Quote:

Originally posted by tridude next time your on the interstate roll your winda down and put your hand out............lay your hand flat allowing air to pass equally owner the top and bottom of your hand..............this is bar out.........now raise your fingertips......feel the air slow down put create power and lift............this equals bar in..... remember this as your flying...........

I use the same explanation .. it hits it spot on! One thing I would add to this is .. when you stop the car and point your fingers up .. nothing happens. This simulates pulling in the bar with light wind. Kite will stall

Ok, so I get the whole AOA, projected area, lift and pull stuff. I was confused on my whole "triangle" point, where if you pull one leg everything else must change to keep the same total angle. Take the "hand out the window" example, which I do quite often because it is fun:D. If the person connected to the lines is the sideview mirror, and your hand is the kite, rotate your hand and imagine what the lines would have to do if they are a fixed length.

That, is my point. Now, after reading the thread that BeamerBob posted, and others pointed out, in theory, and on some kites, the bridle, attached to the front lines, can shift the shape of the kite independently of the back lines.

Now here is my big "however". Look at the picture of the bridle layout of my Apex III and the Speed4. There are mixer pulleys between the front lines and the back lines. When I look at that layout, and I imagine trimming in, I cannot see how it could do that WITHOUT the trailing lines attached. I say WITHOUT because if the back lines are supposed to be MORE slack when you trim in that would mean they are independent of the front lines and the AOA is increasing in the bridle somehow. I cannot see how this would happen with this kite.

Now that I look at the Speed4 line plan also, I am having a very hard time understanding how the AOA can increase independently of the back lines. And if it does not move independently of the back lines, how would the back lines become MORE slack when you bring the front lines closer? This goes back to my whole "triangle" theory. Look at the Speed4 line plan. The front and back lines are 21M. Now, if you were to unhook the back line the pull would be all on A-main. If you were to trim in or out the only thing happening would be the kite getting closer and further away respectively. B-main and Z-main would be too slack to do anything and, from what I can see, would do nothing to the AOA of the kite. Now, hook up the back line and now the mixer comes into play. Trim in, to increase the AOA, and you now mix between front and back lines and it goes back to the whole "triangle" theory.

I understand the "triangle" theory goes out the window a bit because of the mixer pulley but my point is that it is not independent so how can they become more slack?

Does that make any sense?

Big versions;
http://www.rx7turbo.com/images/Apex3_Bridle.jpg
http://www.rx7turbo.com/images/Speed4_Line_Plan.jpg