Power Kite Forum

no-prefill Arc Kite

herc - 1-12-2009 at 10:47 AM

do you have ideas, how to build a new arc kite that needs no prefilling?

* improved air intakes?
* a fifth line or small front bridle that keeps the kite open during launch process and avoids collapsing (tip near tip , inverts, bowties). the 5th line / leading edge bridle could be made tensionless with adjuster. so you could additionally control gust eating, a bit the profile (low end) and autozenith
* what about cutting away the air vents if the arc is only used on land? anyone tried this ? maybe adding additionally small slits to accelerate air filling?
* strange idea: have a temporary launch line, that opens a sort of big "mouth" on the kite that quickly lets air in. if the kite is filled and flys stable, release the line and let it wind up with an automatic winder / just pull it out

any other idea?

sp4cem0nkey - 1-12-2009 at 10:57 AM

Since there are no bridles on an arc, how would it take on a proper wing shape without prefilling it? Maybe a couple curved spars could help with this, but the weight is going to go way up - probably making the arc even harder to fly in low winds...

kiteNH - 1-12-2009 at 11:14 AM

$60 Black and Decker battery powered leaf blower. Takes about 1 minute to fully inflate. Never need to screw around pre-filling again.

PHREERIDER - 1-12-2009 at 12:18 PM

pre inflate a problem? the only time i have ever had problems on a fill ,

- very light air <6mph. this is light! more of an addiction problem than a kite issue.

- off shore, very challenging esp. in a tight shadow spot.

other than that, for a water ride less the a minute more like 30 sec.

for land ride 1-2min. could be 5 -10 min . if i'm desperate and too early for the forecast.

anything added to an arc adds drag, lines/extra spares/weight, they all impede performance.

if it want fill ...take bike ride ..til the wind picks up!

tridude - 1-12-2009 at 12:25 PM

if it aint broke dont fix it...................and it aint broke...................if you need a leaf blower to fill there aint enough wind.....prefilling is a big part of the arcumscision:lol::lol::duh::duh:

markite - 1-12-2009 at 12:44 PM

I think you are missing part of what makes an ARC what it is. The smaller intakes give a smoother leading edge as opposed to an open cell foil and the air is trapped inside keeping it inflated - open cells allow air to dump out and collapse a kite. If you wanted an Arc that wasn't pre-inflated that is really any open celled foil that already exist.
Always thinking of new ideas is good but it sounds like you might be leading toward is how can we make an arc like every other foil.

BeamerBob - 1-12-2009 at 12:48 PM

Quote:
Originally posted by PHREERIDER

- very light air <6mph. this is light! more of an addiction problem than a kite issue.



Ouch, this really hurt Phree. Until now, I was happily in denial. :singing:

PHREERIDER - 1-12-2009 at 12:56 PM

from this pain, growth. but reality puts a PL reactor in the bag just in case.

acampbell - 1-12-2009 at 01:04 PM

Quote:
Originally posted by kiteNH
$60 Black and Decker battery powered leaf blower. Takes about 1 minute to fully inflate. Never need to screw around pre-filling again.


Half the cost if and you don't mind twice the time is a 6-12v 6" muffin fan from a PC (get at radio shack with rechargeable battery). The 2-3 minutes it takes is still the time you need for your line set-up. Weight: about 1 - 1 1/2 lb

kiteNH - 1-12-2009 at 01:21 PM

Quote:
Originally posted by tridude
if it aint broke dont fix it...................and it aint broke...................if you need a leaf blower to fill there aint enough wind.....prefilling is a big part of the arcumscision:lol::lol::duh::duh:


Probably true if you want to go out on the water but for land based kiting you don't need nearly as much wind to fly. And for snowkiting the inland winds can be pretty decent in the sky and really lousy at ground level. With the blower you're FULLY inflated and can get up and flying in lower winds.

But what do I know about any of this when I've only had my Syn out once. I do know that I was desperate to fly it this weekend, couldn't get it pre-inflated in the light sub-10mph winds, blew it up and got a few blissful minutes of flight before the wind died completely.

That radio shack fan is a good idea.

WIllardTheGrey - 1-12-2009 at 02:01 PM

$9.90+
$23.95+
$2.95=$36.80 plus shiping
total Air Flow is 33 cubic feet per minuet, should fill todd's 24m in a couple of minuets:tumble:

or you could get one of these for $19.99

Air Flow: 54.7 CFM:shocked2:

brplatz - 1-12-2009 at 02:48 PM

This should fill my 15m Syn pretty damn quickly


235CFM:wee:
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDispl...

doublespeed360 - 1-12-2009 at 07:06 PM

kitenh. how big is your new kite.

zero gee - 2-12-2009 at 12:58 AM

Or I use something like this...

Not sure of the CFM but it blows at 220+ KPH. Fills my 15m Syn in less than 30 seconds. At 30 sec the kite throws the weight off and the wingtips can't be folded. :smilegrin:

I only need to resort to using the leafblower on days when there is little to no wind down low (a wind gradient). This can happen with warm winds blowing over a colder surface. Like in the winter on the snow, on the ice in the spring and at the water when the water is very cold (like now and early spring). These days can have awesome rock steady winds up high and nicely powered to almost maxed on a 15m Syn and yet there is no wind to fill the kite. Sometimes you can't even tell by looking at the tree tops or flags how windy it really is. Guys in the know on this phenom will put up a kite and have a blast, the guys that don't know look at it and go home not knowing what they just missed out on.

It is also used at sites where the wind is slightly in shadow at the launch. However, the use of the leafblower is few and far between and not the norm. It only comes with me when I go to a particular shadowed launch and /or I recognise the conditions for a wind gradient.

BTW, My local kite shop is also a Lawn and Garden Power Tool shop :smilegrin: They threw in a used rebuilt blower when I bought my G2's through them years ago ('04??). Buy your kite gear and get your chainsaw sharpened at the same time ;)

kiteNH - 2-12-2009 at 11:54 AM

Quote:
Originally posted by doublespeed360
kitenh. how big is your new kite.


12m

herc - 4-12-2009 at 06:14 AM

Quote:


235CFM


wow! thats impressive!

my coleman quickpump has 600liter/sec - this is only 21 cubic feet per second...
and i thought my coleman was powerful :-(



here is a video, how i prefill a scorpion 7 sqm with the coleman quickpump:
http://www.youtube.com/watch?v=eG4Hf6WNpTc


but honestly - there must be a better way. electrical air pump can fail, especially if it is cold and the batterie / litihum accumulator fails. or if it is wet and you get a shortcut. or if there is a little sandstorm, that kills the motor and mechanics of the airpump.

i already posted it, i think, but here again is the rein-arc, that nedds little to no prefill, because of bridles and bigger ventiles:

http://rein-arc.be/?page_id=4

http://www.youtube.com/watch?v=VhGD4Vlb_VM


herc - 4-12-2009 at 07:14 AM

p.s. did anyone here experiment with a "funnel" made out of nylon to prefill an arc? imagine a funnel with an opening diameter of about 1 meter, going down to a 10 cm diameter pipe that is put into the prefill zipper of the arc.

the 1 meter opening could be supported by a small flexible fiber glass beam, or simply held open with your hands and feet.
should that give a real boost ?

and that could be quite easily build. in the easiest form, just take a large bin bag, and open one corner, putting in one end of a toilet tube to make that stiffer and put the other end of the tube into the prefill zipper.

dylanj423 - 4-12-2009 at 07:25 AM

the only arc you should ever even need to consider pre-filling is the large one.... a 7m will need so much wind that pre filling should not be an issue.... even in only 10mph, my 15m phantom has no problems pre filling... the 7m wont really come alive until you get to above 20 mph winds...

zero gee - 4-12-2009 at 09:31 AM

Quote:
Originally posted by dylanj423
the only arc you should ever even need to consider pre-filling is the large one.... a 7m will need so much wind that pre filling should not be an issue.... even in only 10mph, my 15m phantom has no problems pre filling... the 7m wont really come alive until you get to above 20 mph winds...


This is true. I almost never need to use the leafblower for my 10m. Pretty much only if the launch is shadowed.

99% of the time for either of my kites, just set out the kite, open the zip, I setup my bar, by the time I'm done the kite is ready to go. Close zip and go.

macboy - 4-12-2009 at 11:42 AM

Okay, but to entertain the thought a bit, could an open cell arc not work?

zero gee - 4-12-2009 at 12:10 PM

Nope.

This has been discussed and tried way back in the day by ARCusers and kitebuilders. I believe PLK tried it as well with the Hi-ARC but the final release had it closed cell. If it worked there would already be one. Think about what happens when an ARC is not fully pre-filled or loses pressure. The only way to launch an open cell arc is to hot launch them so they are pressurized:o. Now, there will always be situations during flight that will cause loss of pressure in the kite (i.e. wingtip folds /collapse in FB kites). Then forget about relaunching the kite after a crash as it will instantly deflate.

Open cell kites need bridles to function.

herc - 4-12-2009 at 01:21 PM

although it is certainly of great value to have a closed cell arc, that keepsvolume in luffs and especially for relaunching, allow me to disagree that an opencell arc is not possible:

self built open cell Arc sled Kite:

http://www.youtube.com/watch?v=M7pHCne8rMc

http://2e5.com/kite/yagu/



i wonder what happens if you stick large plastic pipes (made from a cola bottle?) into the vents of a current arc, to keep them open? maybe it might be possible to hot launch with no prefill with some skill? anyone tried it? next idea would be to connect those tubes with a thin wire aka "5th line" so you can pull out the tubes once launched and stable at zenith!

dylanj423 - 4-12-2009 at 06:15 PM

why the problem with prefill? and at what point does the extra work of not having to prefill exceed the amount of work of prefilling? cola bottles and a 5th line? why go to that kind of trouble?

zero gee - 4-12-2009 at 07:39 PM

Yes, the Yagu is a very interesting ARC. I like how they thought outside the box there. It flies, but can it really work though?? People have been trying to make one work for 10 years. In order for an open cell ARC to work, it needs to work at least as good or better than the closed cell ARC now. Otherwise it is just a step back. It should not be more complicated than the closed cell ARC too. There are plenty of better performing existing options if you want a more complicated kite.

Sorry if I come across as abrupt. But I have lived through 8years of guys talking about these ideas at ARCusers. Lots of these things have been discussed to death or tried. :rolleyes: I guess some guys just love to tinker. :yes:

Prefilling and launching, relaunching an ARC is not difficult, just different. Great all-terrain kite. They can do most anything you have the balls to do. Great range with a huge sweet spot. Eats gust for breakfast, lunch and supper. Love the autozenith. Robust and low maintenance. The beauty in the current ARC's are their elegant simplicity compared to anything else out there.

zero gee - 4-12-2009 at 09:40 PM

OK, perhaps it took 10 years... Not an open cell ARC, but it does seem to be able to launch without pre-fill. It's called Morphine. http://www.niaboo.com/ The site is in french but it looks to be a single skin arc with cambered LE (closed cell twin skin ram-air at the LE with a single vent). Spars in the wingtips and LE and a simple bridle to hold it's shape. I think it's still an R&D project by one of the original ARCuser tinkerers.

It's interesting. Appears to work well, but better than a closed cell ARC or anything else out there?? It probably takes just as long to setup the spar as it does to inflate an ARC. Long spars break easier. Safe to hotlaunch?? Looks like that may be the way to launch it. You can stall it. Appears to relaunch OK. Looks Stabile.

herc - 6-12-2009 at 06:24 AM

zerogee: thanks alot for digging that naiboo morphine out! this is incredible ! they combined many ideas crawling in my mind into a wonderful kite.

what i do not like: the carbon leading edge battens. i would prefer a solution like this:



black: carbon pipes
red: plastic balls
blue: strong fishing line

putting the fishing line under stron tension would give stability, loosening it would allow for folding up the kite without the need to take the pipes out of the leading edge ! just loosening line pressure and fold up. what do you think?