Power Kite Forum

Dive kite and tips collapse (video added)

shaggs2riches - 14-6-2011 at 08:59 PM

Had a decent ride with the speed 2 this evening except I seem to be having a bit of issue. Say I'm riding to the right and everything is pulling nicely. I go to change directions, and when I turn and dive the kite it pulls solid. When the kite shoots past the middle of the window and starts reaching the other edge, both wing tips collapse and I loose power. When this happens I fiddle with the bar and front lines and the kite will open up. Big problem when it opens it is in the middle of the window, not bad in the 12 mph I was in, but could be dangerous in 15-20 mph. If I dive the kite from zenith, occasionally the lower wingtip will collapse and cause the same issue. My first thoughts were possible oversheeting????? Trimmed in a still have the problem. I must add that I was flying in a bit of turbulence so maybe that was a factor. My conditions are normally like this so I'm hoping it might be just pilot error. Any thoughts on what it could be???? I have two hours of video to sort, so I'll post a video in the next day or two.

Thanks
shaggs

Here is a quick video edit of what I was experiencing. Haven't dug around yet for line measurements for a comparison of my kite. I'm really hoping that its just a wind issue more than anything.

tridude - 14-6-2011 at 09:45 PM

might have been the turb but check your wingtip lines (that run thru the washer)......................if they have shrunk during your water sessions this will occur.......................heres the Flysurfer homepage and youll find the line lengths..........I believe its A15.....................if they have shrunk you can stretch them back to specs by hand........................also make sure you keep them waxed.............just another one of those 25 hour flight checks that need to be performed.................................

http://www.flysurfer.com/wp-content/uploads/lines/speed2/spe...

shaggs2riches - 14-6-2011 at 10:30 PM

Thanks I'll dig around and see if I can get a length and measure mine. Its almost like Flysurfer should have a video available that covers all things related to tuning their kites. When I get the video up you can see how it almost looks like the kite loses some pressure in both tips. Almost looks similar to when you grab the leader balls to backstall, and the tips collapse inwards. Is there anything in the mixer that may have caused this??? I just tuned it, so all knots are in line, I wonder if maybe I made BandC too long causing the instability. My hard/soft steering is in the middle. Might have to try and get it back close to where powerzone set it when he tuned it. I wanted to keep the mixer simple for the first time, now that I understand it I should be able to get it adjusted back the other way.

tridude - 14-6-2011 at 10:43 PM

cool youve gone back to default settings (all in line)....................check your wingtip lines A15 and if it has shrunk, stretch it back to specs then fly it before you go back to B 1.5 C 3cms............................sounds like shrinkage to me.............................if you go back to PZ tolerances make sure to adjust C mixer then B.........................

Kamikuza - 14-6-2011 at 11:51 PM

Stating the bleeding obvious - did you sheet in to stop it shooting past the edge of the window? I'm betting that 12 is a fast little beastie - you gotta keep the FSers on a shorter leash than the LEIs ...

syuzhak - 15-6-2011 at 12:12 AM

I think I had this same kite. Just tune it back to B -1.5 C -3.....Anything less or more and it starts to fly #@%$#!ty.

But also give the ring-lines a little stretch. Dont take them off or anything....just put a screwdriver through the larks head and stretch.

shaggs2riches - 15-6-2011 at 10:25 PM

Do you just measure back 1.5 and 3cm from where the knots are in line with each other then move the knots (my case mixer balls) back that far???? Would that affect then be that they are 1.5 cm shorter than A&Z main???? Gotta measure that ring line as well if I can get a length from the Flysurfer site.

macboy - 15-6-2011 at 10:50 PM

Whoa. I don't see anything like that from the 19. Saw some pretty curly Psycho 4's tonight but nothing like that. I'll be interested to hear what the thoughts are in case mine is similar. It looks like the zipper's open and it's just dumping internal pressure like mad!

(I know you closed the zipper....just a metaphor or whatever the linguistic term is.)

Of course I launched the Phantom at Sunset with the zip open......

Kamikuza - 16-6-2011 at 12:08 AM

Start is normal - you wanna go straight up though, keep it horizontal to fill ASAP.
You look like you're fully trimmed too - the FSers are keen to overfly so longer rear lines will make it worse.
Seems like you're not sheeting in early enough to stop it zooming to the edge of the window ... I'm picking nits though.

And - the wind looks like #@%$#!. I've seen much the same from my S2 in punchy gusty norwesters here ...
Start with the easy stuff - get some clean wind. Check flying line lengths relative to each other. Check the mixer.

From the FSer site you want either the manual or the "line service" page ...

tridude - 16-6-2011 at 06:32 AM

reset your mixer B and C mains and fly the kite powered up.............your loosing alot of edge control trimmmed in that far

http://www.youtube.com/watch?v=PgauDSXp0Gk

kitedelight - 16-6-2011 at 03:28 PM

wow, hope that was a best-of clip, hope that wasn't happening all night. :(

ya, zero settings on the mixer doesn't necessarily = good flight for a used kite. I vote to set back the settings to how you got it, and see how it goes from there. If you like it better, then you can fine tune it more.

shaggs2riches - 16-6-2011 at 05:09 PM

Quote:
Originally posted by tridude
reset your mixer B and C mains and fly the kite powered up.............your loosing alot of edge control trimmmed in that far

http://www.youtube.com/watch?v=PgauDSXp0Gk


Quote:
Originally posted by Kamikuza
Start is normal - you wanna go straight up though, keep it horizontal to fill ASAP.
You look like you're fully trimmed too - the FSers are keen to overfly so longer rear lines will make it worse.
Seems like you're not sheeting in early enough to stop it zooming to the edge of the window ... I'm picking nits though.

And - the wind looks like #@%$#!. I've seen much the same from my S2 in punchy gusty norwesters here ...
Start with the easy stuff - get some clean wind. Check flying line lengths relative to each other. Check the mixer.

From the FSer site you want either the manual or the "line service" page ...


Okay I'll try leaving the trimmer all the way out then. I was thinking that I might have had too much back line, pulling the tips inwards. I'll move B-1.5cm and C-3cm, and hope that corrects the issue. Is there a reason why you adjust C-main before B-Main??? I'm assuming that the end result is both knots are -1.5cm no???? Or is it -3cm???? I really appreciate the help on this, I had a feeling that there might have been some pilot error coupled with everything else.

@ Kami: I agree the winds were complete garbage. Unfortunately no matter where I fly in our are it comes with gusts, shifts, and lulls. Very rare to have a clean wind day out here. That particular session had even more junk thrown in with a huge high school 200-300 meters behind me. I guess its just more fuel for my wife's argument that we should move to the coast.

Kamikuza - 16-6-2011 at 05:32 PM

If your flying lines haven't stretched and you trim in, then you're altering the AoA and the kite will just love to shoot past the window, unless you brake.

Gah gotta go to work right now, will post some links for you about mixer tests that'll answer those questions.

MOVE dude! :lol:

shaggs2riches - 16-6-2011 at 05:46 PM

:lol: well I've fought the move cause I love my job stability, and not sure it will be there where my wife wants to go. I think I've watched all the mixer videos by now. I'm gonna review the flysurfer mixer explanation tonight and see what I missed. Just reading through the speed 2 manual and in it under the trimmer explanation, it basically tells you to let the trimmer out in lower winds...........

To power up the kite some more (more angle of attack) pull on the smaller blue handle. In lightwinds you will generally power up the kite some more with the trimmer further out.

and it says it in the relaunch section as well.....
With low wind it is useful if the trimmer is completely open. Thus the back lines are more tightened.

Guess I've been doing all wrong this whole time and didn't realize it.:lol:

tridude - 16-6-2011 at 06:10 PM

its all good Shaggs, you getting it.......keep in mind your S2 is a Ferrari and needs to be looked over and tuned per Flysurfers recommendations.

For you mixer adjustment=====where the risers (lines to the kite) ABCD rows all come together and form a larks knot are what you want to move.
A main (row) does not adjust, so your adjusting b and c mains (rows). C main should be 3cm lower than A and B main 1.5 cm lower. The links I sent you should give you a good visual and is easy to do. Make sure you mark your mixer ball positions with a sharpie before you adjust and remember to adjust C main then B. Shoot me a U2U if you need anu help...............

shaggs2riches - 16-6-2011 at 06:26 PM

Okay I see I was thinking that CandB ended up shorter and in line with each other when related to A. But as mentioned in the videos if you move Cmain then you move Bmain exactly half that length. When I looked at the mixer when I last did the test, B and C were in line with each other shorter than A and Z on one side of the kite, while B was a bit longer than C(closer to A and Z). I'll tune it up in the morning and give it a flight right away. Its suppose to be windy tomorrow and I have the day off.

Kamikuza - 16-6-2011 at 06:56 PM

Ignore the manual :lol:
And the mixer test procedure in the S2 manual is wrong too - you do NOT line up the ELCs - only the A- & Z-mains ...! S3 manual corrects this

What you trim for is optimum AoA for the conditions - especially if you're a ham-fisted blockhead on the bar like ahem some people :o
- If the wind is good and strong, you can let the trimmer out for max power - the most aggressive AoA to the wind.
- If the wind is weak, trim in a bit to neutralize the AoA and tone down the effect of the bar on the AoA on the kite ...

You can see here how sheeting the bar out is (pretty much) the same as trimming the kite in.
http://www.facebook.com/flysurferkiteboarding?sk=app_4949752...
What the little app doesn't show you is that (IIRC) adjusting C automatically adjusts B by half what you adjust C ... or something :lol: again, you can see something to that effect in the FSer app on the FB page ...

The thing is, if you're flying lines (front or power, whatever you call 'em) have stretched, then you've effectively sheeted the bar in before you even touch the bar. When you sheet in even more and stall the wing - back stall, tip collapse etc etc ...

http://www.foilzone.com/phpbb3/viewtopic.php?f=1&t=13144... should have the most relevant videos ...

shaggs2riches - 16-6-2011 at 08:22 PM

Okay now I get it because C moves B half then, if I move C the 3cm shorter B should end 1.5cm shorter. If B ends different than 1.5cm, I can then adjust it accordingly till it is 1.5cm shorter than A. I'm guessing then because Z is relative to back line length, then you only need to relate B and C to A correct???? Interesting enough I never watched the video on hard/soft steering before. Seems that when I get it tuned back then I'll leave it on a harder setting for now, "so I can feel the kite more". When I was flying it on full soft before I tuned it to default, the bar pressure seemed too light. It seemed that Armin really put emphasis that a beginner would like a harder steering than a more experienced pilot. Also in that pulse1/psycho3 video I caught where it was said that if the tips are folding inwards (like mine are) then you need to shorten the knots 1-3cm. Bingo!!!!That must be my problem.

tridude - 16-6-2011 at 08:36 PM

you got it......................its a 2 to 1 depower ratio so the 3cm input to C main requires half that or 1.5cm on B main...........as Kami stated this gives your proper AOA and airfoil shape...........................you got it now...............dont forget to check main lines and your wingtip ring lines..............

shaggs2riches - 17-6-2011 at 12:12 PM

Here's what my tuning looks like now. Does it look correct???? A&Z are inline, C is 3cm shorter as measured off A-main, B is 1.5cm shorter as measured off of A-main. I removed the wac lines while performing the test, and set it back on the middle knot once complete.

shaggs2riches - 17-6-2011 at 05:57 PM

Took it out for a test flight. No more collapsing tips. It was back stalling a bunch, but I believe that was due to the low lulls in the winds. I took you guys advice and mostly flew it with trimmer out. When I dove the kite I made sure to pull the bar in fast, so that it didn't shoot to the edge. Worked like a charm, I was sailing nicely powered both directions and upwind. The gusts picked up a bit and was really riding fast, and only able to hold my line. I got some sliding direction changes a couple times, but toned it down a bit after my wheels grabbed hard mid-slide, ending in I tumbling onto my head and getting dragged 20 feet on my back. Needless to say I think the kite flies better now, but might drop the steering one knot softer. It started to drizzle, and I thought one more run. My luck it really started pouring heavily just as I landed the kite. I now have a completely soaked kite and all my gear drying in the basement. Looks like its gonna rain the rest of the weekend.:dunno:

Kamikuza - 17-6-2011 at 06:06 PM

Rain for you too huh :( and ZERO wind tomorrow ...

Looks right to me and sounds like you got it sorted! :thumbup:

shaggs2riches - 17-6-2011 at 06:11 PM

Yeah now I gotta learn how to keep this thing flying decently enough through luffs and lulls. Had one invert, but some how I got it corrected, and one real bad bowtie that caused a full reset. Other times it just lost all tension in the lines, and tumble out of the sky like throwing a blanket off a roof. When the winds were right, there was no issue. The rain is a downer, but I'm hoping it clears up the fire bans. Its been too dry lately.

kitedelight - 21-6-2011 at 10:08 AM

Bet its good to have your kite back! Nice feeling.

shaggs2riches - 21-6-2011 at 04:30 PM

Feels real good to have that sorted. I have to say that I was really happy when I took everyone's advice on leaving the trim out, and Kami's comment on pulling the bar in sooner to keep it from shooting to the windows edge. I'm thinking it will fly even better on a lighter steering setting, but I really like the direct response I get from the bar pressure. Real nice when you can just dive it from zenith and it starts parking right off the bat.

Kamikuza - 21-6-2011 at 05:19 PM

Hell yeah :) and my Speed2 is great for that - freakin' Massey-Ferguson (John Deer to you yanks) even at the bottom end!

If the wind drops, either get it up to the zenith, park it there and baby it - really light on the sheeting and gentle, small steering inputs - or (probably easier with your smaller S2) do bacS-P-A-M-L-I-N-K-n'forths at the zenith to keep speed in the kite. Gentle hands again on that.

If you're really stuck, downloop it in the direction it's falling out of the sky, then keep downlooping, using the speed in the loop to get it 'up' ...

Thing is with the FSers - if you can get them in the air, they'll fly. They might not pull but you can keep them up in SFA wind. I reckon 2 knots is the utter bottom end for the SA2 19 - once it's up and inflated, it'll fly in virtually nothing :o

tridude - 21-6-2011 at 06:13 PM

nicely done Shaggs....................good feeling to perform a tuneup then watch her fly like new again....................just to info you and all the FSer pilots I replaced my chicken loop/depower line tonight on the 12m Pulse 2. Checked for line stretch and the front lines were a good 3 to 4 inches longer than the steering lines. Make sure to check this to eliminate back stalling......................

Kamikuza - 21-6-2011 at 08:41 PM

Yeah I found that with the P4 too - 2-3 inches stretch, with may explain why I needed so much trim to stop it backstalling :D

tridude - 21-6-2011 at 08:54 PM

nice find Kami, that should do it......................replaced the CL on the P2 with the megatron and also 5th line FDS from PZ...............found some red amsteel 2, 3/16", with a nice wax coating. Im thinking its the improved amsteel blue with break strength of 5400 lbs. Looks very clean....................

Need to check line lengths on the 13m P3 and 6m Pulse 2 as well...........................

kitedelight - 22-6-2011 at 01:35 PM

ya, good call, did mine a while back and it was quite a bit out. Much better now in light wind and gained some useful depower on the bar I guess I was missing. Definitely worth while.

shaggs2riches - 22-6-2011 at 04:47 PM

I gotta check this now too. Should I disconnect the bar from the kite or can it be done still set up????? I'm also eager to change out the chicken loop this summer some time. Was thinking the new infinity, but its almost worth more than the kite complete.

Kamikuza - 22-6-2011 at 05:20 PM

What I did - laid out the lines.
Looped a spare bit of line through the ELCs (bar side) at the kite then tied that line around a solid object.
Back to the bar - pick it up and lean back a bit, putting the lines under tension ... the theory is that if the lines are all balanced then the sag in the lines should be the same and you should have to apply extra force on the CL to pull it out ...

There's a Cabrinha tech tip that shows the procedure ...

Kamikuza - 22-6-2011 at 05:24 PM



Around 3:45 is the important bit :)

AD72 - 24-6-2011 at 11:26 PM

According to the Facebook app then by shortening the C and B line you are making the kite more stable by reducing the chamber of the airfoil. It also says that it makes the kite more prone to back-stall and slower turning. So there are trade-offs. Although wouldn't this be assuming that all the bridles are stock. Isn't the adjustment to also compensate for stretch of the front edge bridles in relation to the C and B or does that happen? I have been resetting mine to knots straight across.

shaggs2riches - 25-6-2011 at 09:56 PM

I learned a lot from this test. It seemed crazy at first, but makes sense once you finally put it all together. Like you mentioned the kite seems more stable, but I notice the backstall. Which makes me think that it needs to be on a lighter steering setting. Correct me if I'm wrong here, but this is my understanding.

softer steering=less rear bridle tension, less direct feedback,less backstalling, possible better upwind performance, (more chance of overflying if not careful????)
Harder steering=more rear bridle tension, more direct feedback, more backstalling, possible less upwind performance (Less amount of overflying??????)

From that observation is why I'm thinking the harder steering is more suited to someone new to these kites. I could have it way out of proportion, and please correct me if I'm wrong. I'm kinda relating the characteristics to the vpc and internal strap settings on a peter lynn arc. That is similar to how my PL manuals describe what is happening when you adjust the settings on an arc. Again I could have it all backwards and have an open mind, to those who know better than I do.

kitedelight - 25-6-2011 at 11:20 PM

shaggs, did you check your front-back line lengths? not sure what the last post referred to, the mixer or the front-back line length test. If you're front lines are long, and you shorten them, there should be less backstall.

Ad7, ya, my understanding is that the mixer would do both. Adjust it for stretch (to get a happy medium between performance/stability), then that's the new zero point, then adjust it for varying conditions if you want.
But really, if all lined up is working for you, maybe just keep it. Although, if you haven't tried anything other than all lined up, and you have a bit of time on your hands, you might want to tinker,...it is an interesting experience. I need to do more of it myself.

shaggs2riches - 25-6-2011 at 11:31 PM

I was talking mixer adjustments, and hard/soft steering in regards to AD72's comment on more stable profile, but at a cost of more backstall. More explaining what I've come to understand about how the mixer adjustments affect the flying characteristics. after watching all the available videos on the subject. I haven't checked my lines yet, its been raining non-stop for the past week. Hoping to sneak a session on the morning before the rain starts back up in the afternoon.