Power Kite Forum

Can a NPW be tuned enough to park it one handed?

rectifier - 3-5-2012 at 04:47 PM

There was finally a good steady wind out here today, so I was flying and tuning my (homemade) 1m NPW9b. Now there are tons of knots and loops all over the lines by the handles... but it flies pretty damn good. The brake line length is so critical, I went from spontaneous backward flight in gusts (too much brake) to constant nose collapse (not enough brake) to the right setting just by adjusting the brake lines within about 1 inch.

Question is, I can't seem to park it at apex without some control input. If I park at apex and hold both handles in one hand, it will slide down and crash on one side of the window within 20 seconds or so (usually the left side, i think that line may be a tiny bit shorter). Is this expected of NPW kites, are they just not that stable? Is it the size (it's almost like a stunter, super fast and maneuverable) Or should I keep tuning the lines until it will stay put?

I really do like the NPW behaviour in the prairie gusts, feels very powerful for its size but safe. If a really hard gust hits, it tends to temporarily collapse into a flag rather than try to haul me off my feet. It's amazing how much "depower" an NPW has by hitting the brakes, too... really easy to back it down and land by applying the brakes gently.

bigkid - 3-5-2012 at 07:17 PM

I fly the NPW's with PKD handles which have a clam cleat brake adjuster which makes all the knots go away.

If you use a long strop with big loops on each end you can use a larks head on each handle about an inch or so below the power lines to balance the kite. you will have to slide the larks head up or down the handle to fine tune the kite but you will sooner or later get it so you can fly one handed. have flown it that way in smooth winds and just let it park with no hands for a bit.

Bladerunner - 4-5-2012 at 06:34 AM

If one handed is important it would be much easier with the NPW on a bar . Tune it to fly on a bar and it should fly one handed on handles with a bit of control .

bobalooie57 - 4-5-2012 at 07:34 AM

I recently flew my 4.8M NPW5 as a 2-line on a bar in this video. http://www.powerkiteforum.com/viewthread.php?tid=22019 I probably should have posted it in this section, instead of the buggy section. oops!

bobalooie57 - 4-5-2012 at 07:45 AM

I also built a set of handles from 3/4" sch. 40 pvc, and used an attachment ferrule to make the handles into a bar on the fly, here.
http://www.powerkiteforum.com/viewthread.php?tid=20240

Drewculous - 4-5-2012 at 10:51 AM

Dude those interlocking handles are sweet! I had to watch that video a few times when you posted it

rectifier - 4-5-2012 at 11:23 AM

Those handles/bar are pretty neat! My handles are made of 3/4" electrical PVC conduit prebent to 45 degrees They are flared to fit together, but unfortunately, both power ends are flared as I never thought of putting the handles together into a bar. I think they may be a bit short for a bigger kite but they work well on the 1m.

I also like the cleat for the brake lines, I know those cleats from sailing. Maybe I should get a pair of those for my 3m that I am building, my only question is, do they slip when you pack up your kite such that you have to readjust them the next time you fly?


I don't really NEED to fly one handed (yet...) but was trying to take a photo of the kite with my other hand, and was curious whether it was my tuning or if it is the nature of the NPW to be unstable.

Cerebite - 4-5-2012 at 03:08 PM

Quote:
Originally posted by rectifier
Question is, I can't seem to park it at apex without some control input. If I park at apex and hold both handles in one hand, it will slide down and crash on one side of the window within 20 seconds or so (usually the left side, i think that line may be a tiny bit shorter). Is this expected of NPW kites, are they just not that stable? Is it the size (it's almost like a stunter, super fast and maneuverable) Or should I keep tuning the lines until it will stay put?


I think it is probably a little bit from pots A, B and C. First off my gut feel is that 20 seconds of stable parking at apex sounds pretty impressive for a kite of this style.

Mine are very sensitive to differences in flyer to kite distances so there is a good chance that there is a slight difference in where you "final" knot ended up on either side.
Being a single skin kite there is less structure to "hold" the wind than a foil or a framed kite so it needs steady line tension. I find mine to be much happier when "sheeted into the wind" than when flagged out on the power leads.

At the small sizes it seems that all quad line kites tend to behave like a humming bird on espresso or that squirrel from Over the Hedge.

zero gee - 4-5-2012 at 06:46 PM

Anyone ever try the paraskiflex bar on a NPW? Like this one I tried with my Syn's. Could be an interesting option??

bobalooie57 - 4-5-2012 at 07:43 PM

Here's one with my 7M, at 5:04 I one hand it for a while to take some vid, stropped in to the harness.
http://www.powerkiteforum.com/viewthread.php?tid=20068

rectifier - 5-5-2012 at 10:49 AM

Wow, I've never seen such a system (paraskiflex). I looked at their kites, and they are really quite similar to NPWs, even though people who paid money for them claim they are not :lol:. All they really are is a simplified NPW with a leading edge stiffener, in the videos they have a very similar leading edge "tucked nose" shape. In fact I don't see why a NPW wouldn't outperform such a simple single skin foil... yet their foils are apparently extremely popular in Quebec, perhaps due to the easy control system?

I see no reason why a NPW won't fly on such a bar with short lines, it looks like a great setup for park riding. Just point the kite where you want it to go, move your hand up and down the bar to adjust brake bias. I have done a similar thing with my handles held close together on short lines but never thought of using one bar... I'm going to have to try that when I get my bigger NPW built.

Bob, nice NPW cruising, is that your 7M? Looks like yours is pretty stable. Who knows, mine might have just been knocked over by gusts, it was a pretty gusty day here... here's 10s of video that I managed to shoot one time I had it up one handed.

Edit: first time posting a youtube video...

herc - 5-5-2012 at 03:17 PM

difficult, alternating, changing low wind conditions. yet, it was possible to fly the nasastar using the paraskiflex style bar one handed. though i really prefer to fly the nasastar in 4line mode on handles. gives me much more control.

John Holgate - 5-5-2012 at 05:45 PM

That Paraskiflex rig looks a bit awkward to me. You can certainly run an NPW on a two line bar....which is what my Nasa Star 2's essentially are. Or handles. There is a third 'depower'/'flag out' type line rigged in the center of the kite but you don't need to use it. I've tried the 2.5m in four line mode with a Turbo Bar but it turned far too quickly. Might work better with power lines to the outside of the bar and brakes through the center - haven't tried it yet but there's plenty of ways to skin a cat....

Some details of the two line bar (and using the third 'depower' line) here:




and some buggying....


rectifier - 5-5-2012 at 07:53 PM

did you just go out and try it today Herc!? Not much wind but it looked pretty easy to fly.
Are the brake and power lines the same length or did you have to do some tuning? I noticed no nose collapse which is good for those conditions.

I agree handles will obviously give more control. The paraskiflex bar sort of turns your kite into a kitewing... takes some of the fun of flying away for sure, but might be good for messing around in the park, on the road or in small boats etc... where you want to keep the kite close and under strict control.

John: I tried flying NPW on 2 lines and personally thought it really handled like a dog compared to on 4. Slow turning and hard to keep edged into the wind as you lose that brake bias control... also you can only hot launch which scares me as a rookie. It obviously works for you though

John Holgate - 5-5-2012 at 09:20 PM

Quote:

also you can only hot launch which scares me as a rookie.


I tend to do a 'cheat's' side launch...I'll walk around a bit to the side then as soon as I pick the kite up, I put the kite on it's side and quicken my pace in the opposite direction. Certainly not a true side launch, but it helps.

herc - 7-5-2012 at 05:49 AM

@rectifier: no, the vid is a few days older. no tuning needed !
i found out later that you can avoid some tip - flutter if you also put all tip lines ( nasawing specific: all B-Lines) to the front lines. just the last two inner A's as brake.

i also experimented with a depower setup for the nasastar:

https://picasaweb.google.com/111510368262264907350/28April20...



this way you can quite nicely control the power in the nasawing and its also very helpful if you have phases of total light winds. with this setup i could completely avoid that dreaded stalling and backwards flying behaviour of all nasawings that they show in gusty light winds.

disadvantage is that the nasawing starts to flutter if depowered. you can avoid that as said above by putting all outer tip lines to the front. than they act sort of like the stabilo of opencell kites / paragliders and keep the sail tension to some degree.

anyway. if you dont care about flutter, i can only suggest such a simple depower mod, because you can instantaneously regulate / drop power in the kite if a gust hits you.

John Holgate - 7-5-2012 at 03:12 PM

That's very interesting, Herc. I wonder how it would go with a depower bar setup and long lines.....might have to get some pulleys and try it.

rectifier - 7-5-2012 at 03:43 PM

That's neat, any video of it working? Does it still fly like a NPW or does it handle more like a depower now? I notice it is still on handles and not a bar.

Does it really adjust the AoA of the entire parawing or does it just change the way the brakes are applied to dump air? You are saying you get better performance in light wind (like a depower that has been... depowered) which implies the AoA is indeed changing. This would be great to keep it off the ground during a lull when it comes gently drifting down, sail still full but not quite enough wind...

I would love to see specs as to how which bridles are attached where. Is a nasastar a NPW5 or NPW9? All the tinkering is really what is fun about NPW kites

herc - 8-5-2012 at 02:51 AM

here is a video showing the depower mod in use.

http://youtu.be/8VKKKYeHCZk



the mod really helps me to keep the nasawing in the air even if the wind drops almost kompletely. also, i can regulate power. because on inline skates, you can get very fast even with a small gust (because you have almost no friction on a good asphalt road) because i am scared of too much speed with inline skates (n helmet, no pads - my bad) i just release the handles. the nasawing then starts to flutter but looses most of its pull.

i fly on handles because i have more control. of course, you have a bit more pressure on the back lines but with this 4 sqm nasastar II , its ok. with a bigger nasawing i can imagine using a bar will be better. as you can see in the video, i am grabbing the handles more ini the middle, such that forces balance better.

yes, this mod really changes the AoA. of course, the nasawing has only a very small AoA range, where it will not flutter. but the AoA range with flutter and less power is larger. i have little problems with nose collapse, but i think this might be because its a nasastar. maybe a npw5/9 will have more nose collapse..

regarding the bridles: you usually have twelve rows of inner bridles. i take the first four to the frontlines, the next four to the pulley and the last four to the brake. all outer bridles go to the front lines. if you have another set of inner bridles (like with the npw9) just distribute all inner bridles in proportion to the depower pulley layout..

btw, you should use a little steel ring instead of the pulley. i noticed that with my rather heavy pulleys the bridle tends to entangle...

you could even use a two pulley / ring depower mod - then you can keep the profile smoother. but is it really worth the effort? its then harder to get all lines to equal length if you have the depower bridle in neutral position.

how i made the depower bridle :

just took two approx 2 meter long kite lines (for each side). then put loops on each end. next, i put the pulley in the middle. then i arranged the line to lay in zigzag and put at the lower zags (where front and brake lines will be attached) smaller loops that i could readjust by putting them on using a prusik knot:

http://www.animatedknots.com/prusik/index.php

so i could slide them up or down on the depower bridle to adjust everything to equal length.

hope that makes sense.. if not i will make closeup - pictures this evening.

rectifier - 8-5-2012 at 08:14 PM

Neat. It does seem to have quite a narrow range in which it doesn't flutter, maybe it's not for me (yet). I spent ages just tuning all the flutter out of my NPW! Though from the stalls at the end it looks like your video involved VERY light wind, so the performance may be better than it appears, maybe the kite would have been stalling instead of fluttering if not modded?

I think I'll have to get a couple of stock NPW builds under my belt and understand the bridling a bit more before I start trying this kind of mod but I do find it interesting. I like the ability to dump power rapidly and think that would be useful in many gusty situations. I hope you keep developing this, it's a great direction for nasawings to go in. They are already a great inland kite and this kind of mod could make them even more versatile in our gusty wind.

bigE123 - 14-2-2013 at 05:51 AM

In response to your original question, add dual brake lines. Make a second set of brake lines for A11/A12 (and B/C depending how many bridle sets you have) and run them to the QP gather. That way there is brake input even when you let the brake lines go loose, which prevents nose collapse. May need a little tuning but once set-up it then doesn't need the level of brake / power balance.
When you add brake input for turns or back stalling you see the additional lines go slack as you now have control through the brake line as normal. ;)

bigE123 - 14-2-2013 at 05:59 AM

And if your thinking de-power



This is the set-up I made and use on my 8m and 11.8m NPWs.

kitemaker4 - 14-2-2013 at 08:15 AM

I do not see why you would want to fly any kite with one hand. I like to have as much control as possible when I fly so I use both hands. I have a few handles that have cleats for adjusting the brake lines in flight and I find them useful.

Susan (npw goddess)

Quote:
Originally posted by rectifier
There was finally a good steady wind out here today, so I was flying and tuning my (homemade) 1m NPW9b. Now there are tons of knots and loops all over the lines by the handles... but it flies pretty damn good. The brake line length is so critical, I went from spontaneous backward flight in gusts (too much brake) to constant nose collapse (not enough brake) to the right setting just by adjusting the brake lines within about 1 inch.

Question is, I can't seem to park it at apex without some control input. If I park at apex and hold both handles in one hand, it will slide down and crash on one side of the window within 20 seconds or so (usually the left side, i think that line may be a tiny bit shorter). Is this expected of NPW kites, are they just not that stable? Is it the size (it's almost like a stunter, super fast and maneuverable) Or should I keep tuning the lines until it will stay put?

I really do like the NPW behaviour in the prairie gusts, feels very powerful for its size but safe. If a really hard gust hits, it tends to temporarily collapse into a flag rather than try to haul me off my feet. It's amazing how much "depower" an NPW has by hitting the brakes, too... really easy to back it down and land by applying the brakes gently.

bigE123 - 14-2-2013 at 09:03 AM

I don't think it's to generally fly one-handed, it's just while it's sat at the zenith. Flying one handed whilst doing anything else... now there's a recipe for disaster :yes:

But dual brakes on a NASA helps prevent nose collapse and is useful when using a strop line

John Holgate - 14-2-2013 at 07:36 PM

Quote:

I do not see why you would want to fly any kite with one hand.


For me, it's so I can film. It's mostly why I use a bar because I can fly that one handed more comfortably than handles. To a point - once the wind picks up and the kites get smaller then there's no more one handed shenanigans!!