Power Kite Forum - Which NPW, I'm totally confused

Which NPW, I'm totally confused

B-Roc - 23-3-2015 at 06:56 PM

So, all these threads on street kiting, NasaStars and NPWs have me really interested but I still, for the life of me, can't figure out what the difference is between a NPW2, 3, 5, 9 (and I'm not talking meters I'm talking models). Are they all basically the same thing? Z lines and splitting bridles confuses me a bit as I've been flying depowers for years and haven't spent enough time reading up on NPW advances.

That being said, I do want to get a set, I do want to fly them on a bar, I need to fly them on short lines or the bridles.

The way I see it, I can go with Susan and get a NPW9 in a week or so or go with Steffen and get one in a month or so. Is there a benefit of one model (2, 3, 5, 9. etc.) over the other? Does the depower really work? Do I need to add or reconfigure Z lines or just split them? Can I fly all sizes on the same bar or like foils do you need to scale the bar to the kite size?

I'll be flying these kites only on pavement with my longboards. My guess is in winds from 5-20mph. What would the ideal NPW quiver look like for those winds at 145#s?

Any help would be appreciated and if you have any NPWs you want to sell, send me a PM and maybe help me make a decision.

Thanks

ssayre - 23-3-2015 at 07:29 PM

I have no idea on the different npw's. Susan or bigE might know. Cerebrite and bobalooie57 use susan's npw's (not sure which type). I have know idea how they would compare to the nasa stars. I kind of always assumed they would be similar but not sure.

I did give some thought to how I would set up a standard npw on a bar though. I'm pretty sure all npw's can combine the brake and power bridles making it a 2 line kite which would be ideal and similar to my nasa star set up flight wise and eliminate all the 4 line z bridle messing around. The depower is not necessary other than a safety. If you used a 2 line bar, I would think you could have extra long leaders and have a kite killer connected to one side. The side it connects to would have a leader that would slip through a ring that would effectively flag out the kite in theory. I think I've even seen a 2 line bar made that way. Then you would have the benefit of bar control (which is key for longboard in my opinion) with nearly the same benefit of kite killer system. I don't know if I explained that bar set up well but I can elaborate or try to find a picture of what I'm talking about.

The way I see it, if you can confirm they fly well off 2 lines and you can kill power, that's basically all you need.

I almost forgot, Randy has both and bigkid have both so maybe they have or can test out 2 line on bar flight with the npw's compared to that of the nasa star.

I'd drop randy a message.

soliver - 23-3-2015 at 08:10 PM

I think Susan Makes NPW5's but not really sure.

From what I understand (and I know others can elaborate much better than I) the models of NPW differ mainly in how large their window is and how easily they fly. I have exchanged a few emails with BigE123 and I think he said that the NPW21 is his preferred model because of the size of its window and ease of flying over the NPW5 or NPW9(b)... don't quote me on that as I might be wrong.

I think the Born Kite NASA Stars are kind of the culmination of all you want in a NASA style kite. While I haven't flown one yet (as mine are floating in the limbo of US Customs), I understand that they are SUPER easy to fly, SUPER stable, and have a markedly better upwind ability than other NPW models due to a bigger wind window. The other major advantages of the NS3's is the really tight turning radius and the "depower" set up which for all intents and purposes it more of an alternative way to kill the power over depending on brakes. They are Steffen Born's own iteration of the NASA wing design which he has improved on over multiple models (Now on #3)... that is all based on what I have read though.

If you're interested in a standard NPW (over a NS3), shoot Susan a U2U and she'll give you pricing on whatever you want.

just my 2 cents...

Randy - 23-3-2015 at 08:53 PM

The various NPWx are just different variations of the same design. There are 3 or 4 main models - the 5, 9, 21 and Nasa Star series. The NPW 5 is a pretty simple basic model. The NPW 9 was refined a lot by kite experts and is now probably the highest performing model (in terms of wind window and pull.) The 9 is wider than the 5 and the 21 is wider than the 9. The 21 has not been as fully refined as the 9, so while the window is as wide, it probably doesn't have as much pull. It is easier to fly, but you have to build one yourself. There are a lot of other variations and I've built and flown several of them, even a few I cooked up on my own based on combining other ideas.

Nasa Star is really a variation on the 5, from what I can see but has a much wider center panel. It is really intended for 2 line flying, and has a unique 3rd line braking/depower system. It is very easy to fly. It could be flown 4 line, but not at all necessary, nor that commonly used as far as I know.

Susan make the NPW9 and it is very powerful and has a very wide window. I've never flown mine with 2 lines, and it pretty challenging to fly compared to the other models. Its probably the best kite for an expert NPW flyer. I think to really take advantage of it, it pretty much needs to be 4 line and careful attention must be paid to the brake settings. It seems to me they require some tweaking from day to day. I'm still really learning to use the 9. I've built two (1.2 and 1.8) and have a 4.0m built by Susan. I've used the 4 to pull my landboard with short lines and it works well for that.

If you want to buy one - your choices are pretty limited - a NASA Star from Born or have Susan make a 9. Or make one yourself, which can be any model you like. Not everyone would want to spend the time needed for that however. The money you would save by making it yourself (if any after buying the material and tools) would be less than minimum wage per hour spent building it. (I just build them for a hobby, and because I like to swear at my sewing machine.)

If you want visit my youtube page you can see what they all look like.

https://www.youtube.com/channel/UC19616vtWS03nWD5zFEt5Fw

Hopefully Susan, Ian, Big Kid and some of the other experts will weigh in on this.

soliver - 23-3-2015 at 09:15 PM

Thanks Randy... I got some more NPW education there for sure!

bigE123 - 24-3-2015 at 03:42 AM

Ok here we go :D
NPWs were the original NASA experiments to find a chute for landing space things. There was extensive research done on them and IMHO more testing than any other kite to-date, the reports are still used as a reference / bench mark.
Whilst the initial design was similar they experimented with different keel cant angles and widths from model 1 to 23 showing all the data from wind tunnel testing. The report data showed all the flight characteristics and in addition also showed differences in bridle length changes.

At some point the kite world got interested and the first plans for a model 5 appeared followed by the 9 with various little tweaks to the design to make them more kite like and along came things like a high aspect version and a Teega both based on the 9b. I built a couple of 5s and 9b's before being tempted by the 21.

Once I built the 21 it felt like a different kite to the 9b, it feels more stable and refined. I know what Randy is saying about power but for me stability is key and the power on it builds. Looking at the NASA data the 21 also has the best lift/drag ratio especially with a longer bridle set on it.

Obviously the NASA star is a NPW variant with it's extra wide centre panel and extra bridle set for the nose control. What all these kites suffer from is window size and to some extent or other the nose collapse. What they do offer is a compact design, immediate power and extremely usable, unless you're pushing the limits they are less lifty than other kites, I say less because the can loft in higher winds but as I said they do let you know it's coming, as you send it up the power just keeps building at that point you either re-direct, add some brake or just go with it and they just lift, glide and let you down.

As the 21 felt like the most stable design, I have tried various things out and as Randy said is still work in progress but when does it stop? When I got PL's skin to test I did a back to back with my 21 and tbh there was very little difference in performance and to me the 21 still had the edge. My NPW21 now has a different profile on it and is flying really well, it just shows how good the design is when you can try different things out.

As to where you can get them, obviously they are a kite builders friend, pretty straight forward, NASA Star is the only commercial outlet, Susan obviously. I have built some for other ppl but what I don't like to do is compete on price, I use the best material and bridle lines, as I build mine to fly as well as they possibly can and would not compromise that ethos for a build for someone else. I also test and tune the kite before sending out.

You also mentioned the Z-bridle, once set-up you should not really need to adjust it, with it fitted you hold the handles like a foil. It also gives the option of throwing it on to a bar, it does work very well with the Turbo bar. The only thing I did need to do was add longer leader lines to the bar.

So to sum up they all have slightly different characteristics, much like different foils. You won't go wrong with any they all do a job, it's down to how well they do it. I use mine and really enjoy the additional skill they need. Step towards a Peak style and it's a game changer.

bobalooie57 - 24-3-2015 at 07:57 AM

Susan's NPW's are the NPW9, and they fly well on both handles or on a 2 line bar, although I tried my 12M on the bar in what I considered light wind, and got tossed pretty good. I think my short lines and bar made the big girl so twitchy that there was little time for reacting to the quick change in direction. That said, with your winds (5-20), and your intended use, long board on pavement, I would think that a 2M and a 5M would get you by. My smallest NPW is the 5 model, at 2.4M(HQ- I don't think they make them anymore) and I've flown that on the beach in the buggy in up to about 30MPH wind, on 10M lines. I've also flown the same kite in 15MPH wind with 20M lines and still got traction. I'm usually switching to the 4.8M (NPW5, also HQ)by this time, using the lineset that seems appropriate for the wind. Around 5-10MPH, my 7M or 7.6M (NPW9-Susan) is usually working for me. I keep the 7M on short (10M or so) lines, and the 7.6M on 17.5M lines, so lighter winds get the 7.6, stronger get the 7M. I also have a 3.4M NPW9, by HQ, which came from the factory with the Z bridle installed, though I don't use it, as I prefer to have the freedom of no brake input if I want it. Susan's work is quality, and I love the fact that they are made by one of our own. I hope that helps.

kitemaker4 - 24-3-2015 at 09:16 AM

Well. The kites I make are the npw9 version. It has more power and a larger wind window over the npw5. I fly strictly on handles which gives you the most control. I have never flown using a bar since you have to rig up the kite as a two line verses a 4 line on handles.

My understanding about the nasa star kites with the third line for depower is that the depower is used to land the kite. You are flying the kite as a two line kite with the power and brake lines together. If I am wrong about this then someone please chime in and explain how it works.

Nasa has a website with over 20 versions of the nasa wing kite out there. A lot went into testing in wind tunnels. It might be a good read if you have time. I would post the link but I am using a new computer and have not added it to my favorites.

Susan (npw goddess)

bigE123 - 24-3-2015 at 10:13 AM

And a page for all NPW type stuff: http://2e5.com/kite/nasa/

ssayre - 24-3-2015 at 11:37 AM

Quote:

My understanding about the nasa star kites with the third line for depower is that the depower is used to land the kite.

While technically you could land it using the third line, it can invert the lines and spin a few times creating unnecessary twists. I use it as a safety only. To land the kite you just steer to the edge and park it on it's side pointing down.

John Holgate - 24-3-2015 at 02:08 PM

Quote:

Quote:

My understanding about the nasa star kites with the third line for depower is that the depower is used to land the kite.

While technically you could land it using the third line, it can invert the lines and spin a few times creating unnecessary twists. I use it as a safety only. To land the kite you just steer to the edge and park it on it's side pointing down.

While I use it as a safety only too, it is actually designed to be able to depower the kite while in flight to any degree you want. I just don't particularly like the way it behaves when partially depowered at speed in the buggy and as the kite is so forgiving in the first place, I now just use it as a safety.

I did used to land the kite on the center line until I saw the 'side landing' method that Steffen made a video of and have used that method ever since.

The beauty with these kites is you can rig up the steering however you want. I've flown them 4 line handles with and without the Z bridle and on several different types of bar setups. I still prefer the bar because of it's ease of use and while it doesn't give me separate brake control, the NS2's an NS3's can be reversed launched on two lines because of their steep angle of attack. 99 times out of 100, they side land easily and are well behaved while on the ground so I'm not really missing separate control of brakes although the option is there if I want it.

If you haven't seen Dreams of Sand it gives a pretty good look at the NS3. There's also a review vid where I show it reverse launching after plowing it in nose first.

3shot - 24-3-2015 at 03:21 PM

The depower feature is what sold me on the Nasa Stars. Like others said, if you use it as a safety and let the kite rag flap to the ground, just grab the bar and give a few yanks. The NS will roll around and relaunch 95% of the time. At least in my experiences so far.

skimtwashington - 24-3-2015 at 06:25 PM

Think B-Roc is less confused or more confused now?

I have seen Susan's work and it is impeccable. Top quality bridal lines...stitching...everything...... and you can customize colors!

I have briefly flown the Born kite and the depower line seems a unique safety system to the Nasa wings that is surefire.

...but also the fact that you can take out 'any degree'(John H.) of power is a feature it is designed for, may also be considered.....

But not having enough experience with it in a semi depowered situation I can't comment about it's 'behavior' in that mode.

Maybe John can enlighten on that...

ssayre - 24-3-2015 at 08:01 PM

They still steer depowered. The performance is affected incrementally by the amount of depower. It does come in handy if the wind changes drastically and you find yourself overpowered. I've made it back to where I started to land instead of landing far away and walking back. That circumstance is fairly rare but does come in handy. Also, it's more comfortable using the depower function on landboard since you are facing the kite. I've only landboarded a few times though.

John Holgate - 24-3-2015 at 09:42 PM

Quote:

But not having enough experience with it in a semi depowered situation I can't comment about it's 'behavior' in that mode.

Maybe John can enlighten on that...

The words 'Squirelly' and 'nervous' come to mind. Seem to remember flying the Ozone Flow 3m on the turbo bar with full brakes pulled (only get away with it once you're going a good speed) - sorta felt the same.

Have occasionally been overpowered and pulled a little depower on which has worked really well, but I much prefer 'em full power.

bigE123 - 25-3-2015 at 04:07 AM

I still find the de-power approach on the NS odd, it's almost like... "right we have the kite set-up, flies well but we can't pull the brakes, tell you what lets force a nose collapse." I know there are different ways to to skin a cat but unless it's a way to get around patents who knows why this approach.

Randy - 25-3-2015 at 04:54 AM

Ian,

I think its a sort of elegant way to apply the brake as a safety. I've never felt like it does all that much in terms of reducing the power. To me its more on an on or off sort of thing, though I have not fooled with it much. You could use it to "tune" the kite down, but going to shorter lines accomplishes that better. I've noticed that apparently most of the NS users only use it as a safety.

Quote: Originally posted by skimtwashington

Think B-Roc is less confused or more confused now?

I think we've made it as clear as mud. After all, NPW kites aren't rocket science.....anymore.

bigE123 - 25-3-2015 at 05:21 AM

I think what we've unintentionally done is create even more debate/preferences over the different kites, the one thing to remember is that each in isolation will do it's job and that is to fly as a traction kite. As a kite builder we have the luxury to try different models out at cost and I can see how looking at it from a which one to buy is a bit of a dilemma.

bengineer - 4-4-2016 at 06:37 AM

To pick up an old thread...
How can you use handles (with brake lines) to reduce the power of an NPW kite? I understand that the NS depower approach makes the kite partially collapse so it makes sense to me.

Windstruck - 4-4-2016 at 07:01 AM

Quote: Originally posted by bengineer

To pick up an old thread...
How can you use handles (with brake lines) to reduce the power of an NPW kite? I understand that the NS depower approach makes the kite partially collapse so it makes sense to me.

Seems there is a lot of these sorts of questions up in the air this week! I would suggest taking a gander at the Z-bridle thread here on PKF and ultimately suggest going that route when flying Born-Kite NASA Stars off of handles.

http://www.powerkiteforum.com/viewthread.php?tid=31880

Somewhere there is a description of how to fly the NSs as 5-line kites, using the center line as a tethering safety for flagging out. I've got some ideas on how I'd do that but would probably just leave this central bridle line attached to the top of the kite and ignore it when flying on handles.

ssayre - 4-4-2016 at 08:42 AM

Quote: Originally posted by bengineer

What the what what?? What is your intended use for the kite? Traction or static?

I'm not sure using brake lines will reduce the power but will cause a stall and an annoying backwards fly.

When rigged with z bridle, the benefit of the brake lines is to be able to land as you would a normal foil and for easier reverse launch. Beyond that it might make the turns a little snappier but that's about it.

Running them without z bridle will have a larger spectrum of power usage available to you through use of the brakes but takes more skill to fly. With little brake line tension, the nose will want to collapse and wingtips flutter which reduce the power, add some brake tension and the power increases, add more brake tension and induce a stall. Finding those fine power increments and setting to memory is the challenge.

bengineer - 4-4-2016 at 12:12 PM

The reason for my question is that there seems to be a notion that if you fly an NPW kite with handles you can depower the kite when strong gusts come. I think your answers say that's not the case. It sounds like the depower line on the NS kite is better suited to that.

I'm mainly interested in depowering my NPW kites when gusts are too strong while in the buggy or static flying.

ssayre - 4-4-2016 at 12:53 PM

Quote: Originally posted by bengineer

The reason for my question is that there seems to be a notion that if you fly an NPW kite with handles you can depower the kite when strong gusts come. I think your answers say that's not the case. It sounds like the depower line on the NS kite is better suited to that.

I'm mainly interested in depowering my NPW kites when gusts are too strong while in the buggy or static flying.

I do not use the "depower" function on the nasa stars other than to release to safety in emergency. You can use the 3rd line as a depower with the nasa star BUT the full force is on your arms and not the harness. The third line is connected to the harness but it doesn't bear any power. The born-kite 3 line bar is equipped with an additional way of activating the depower while still being hooked in. There is a yellow ball that you can pull to acquire the desired amount of depower but that's at the cost losing a hand to third line maintenance and trying to steer at the same time. It's also usually not quick enough to get to in a gust.

Windstruck - 4-4-2016 at 01:00 PM

Quote: Originally posted by ssayre

Quote: Originally posted by bengineer

Sean speaks truth here. I have tried to use the little yellow ball from time to time to try to rescue myself in an overpower situation while buggying. My buggying in these settings have been on soccer fields where you absolutely need to avoid things like soccer goal posts (sucks when you slam into them as I can personally attest to) or absolutely need to turn around before running into the bleachers, lights, a fence, etc. Much different situation when on a wide open surface such as the Ivanpah playa, a big beach at low tide, etc.

One thing to keep in mind is that when moving fast in a buggy in an overpowered situation pulling on the yellow ball will make the kite fall backwards in the wind window as it looses some steam. If you don't take the kite all the way down to the ground then at some point the kite dips behind you. Release the little ball then and your kite will surge forward with a big power boost. Presuming you pulled on the little yellow ball because you needed to, this can make for quite a tense couple of seconds. So for me, I like the central line on the STARS more as an emergency cord for keeping the kite with me after pulling the chicken loop free, but not so much to scrub a little power without full deployments. I think this is pretty much what Sean was saying too.

Cerebite - 4-4-2016 at 05:17 PM

In my thinking and experience the "depower" of a standard NPW is in the brakes. To get good power from a NPW you apply more brake pressure to "latch" onto the wind, to get less power from the kite [depower] you apply less brake pressure or let off the brake pressure which in its extreme results in the "ragflapping/ ragflapper" moniker that NPW flyers carry.