Internal Pressure Test on Chargers...

Kitesurfing/Kiteboarding on Liquid H2O

Re: Internal Pressure Test on Chargers...

Postby Timothy Grossnickle » March 16th, 2012, 6:11 pm

Mark,

I agree with Tungsten about the vents in the shoulder. The Lynn's put shoulder vents in one version of the original S arcs. They took in lots of sand. My buddy a good kiter was cussing his S arc one day for collapsing. (sound familiar?) I picked up a corner to help him relaunch and felt a lump in my hand. We emptied out a cup of sand from each tip. Amazing that the kite flew at all, much less have problems with collapsing.

Jim,

Don't know how to attach pictures for the velcro zip closure with tape. I use sail tape and simply wrap the tape over both sides of the opening. Although any tape that sticks I think would accomplish the same thing. As to how much taping over Syn opening would help, I don't know. Have taped over my Syn's velcro openings, but have yet to fly them. I'm mainly on Ch 19 and Ch 15 now. Would suggest you can test the air pressure loss easily with a leaf blower or the exhaust port from a shop vac. Just stick the blower hose in the deflate zip and close the zip around the hose. With your had you can feel if any air is escaping. If you are losing air, tape the opening. You may want to leave a tiny amount of the opening untaped as I have. This would let some water escape if you dropped the kite. With the stability of Arc's I have except for the hand clapping of Ch 15 rarely dropped kites for more than a few seconds. Therefore the water release never troubles me. So far the Ch 15 with velcro tabs taped shut and T's 5 cm center strap mod the Ch 15 hasn't collapsed. The Ch 19 never collapsed, but has shown increased stiffness and more power in flight with the velcro tabs closed.

On the need for more vents on Chargers, I'm thinking after a couple of light wind sessions on Ch 19 and 15 with velcro tabs taped shut that two vents could be enough. My problems with the exhaust zip opening and the velcro letting out a lot of air could stem from washing the Ch 15 after each crash when it got caked with sand and salt. If I hadn't and the sand and salt might have kept the deflation zip and velcro tabs closed.

Regards,
Tim
Timothy Grossnickle
 
Posts: 162
Joined: January 14th, 2012, 11:51 pm

Re: Internal Pressure Test on Chargers...

Postby Albatross Mark » March 16th, 2012, 8:14 pm

Got two Syn 15 inlet vents ready to go into Charger 15,,,,,sewing machine ready. Now where?This is fun .Gosh i missed the early days of kiting and kite developement.Wish i was there.Oh well i am here with Tungsten for Arc improovements which this Charger drastically needs.Too bad VO wont work with us.
Albatross is a huge seabird that soars the waves and winds of the high seas mostly in the roarimg 40's. Albatross Mark tries to mimmic this bird using the following kites: 8m Vortex,10m Venom,8m P3 FS,10m North Rebel ,10,12,15, 19m Psycho 4 FlySurfer
Albatross Mark
 
Posts: 464
Joined: June 25th, 2010, 7:36 am

Re: Internal Pressure Test on Chargers...

Postby tungsten » March 16th, 2012, 9:16 pm

Right... Mark, before you fire up your sewing machine and sharpen your scissors, let me say that this last post of mine was a J O K E. I thought this was obvious, but obviously it wasn't.

It's TRUE that PL put two big rectangular air intakes in the middle of the kite as the result of a long developing process. It's NOT TRUE that I believe more air intakes are an advantage. I do not think so. There is stuff I believe you can make better (read my posts so far), and there is stuff I would not touch because I believe PL have done their homework. Well the air intakes are part of the latter. I have reasons to believe so. Don't bother asking me, it's tl;dr stuff.

For the sake of flyboy's, please do not cut into your CH before he has tried it. Makes him happy and gains you 1.000 karma points. Now is that something?

cheers, tungsten
tungsten
 
Posts: 483
Joined: March 22nd, 2010, 8:19 am

Re: Internal Pressure Test on Chargers...

Postby Hardwater Kiter » March 16th, 2012, 10:50 pm

If you want to ad vents to an Arc make some like the vents on a Vio kite. Positioned mid-chord so that the wing will take air while sitting on it's trailing edge. Launchabilty of a Flysurfer then.
"The rider makes the kite."
Owner/instructor @ http://www.hardwaterkiter.com
User avatar
Hardwater Kiter
 
Posts: 353
Joined: July 8th, 2010, 3:39 pm
Location: Cow Hampshire

Re: Internal Pressure Test on Chargers...

Postby tungsten » March 17th, 2012, 8:04 am

HK, yeah that would be something new and worth a try. Would not enhance internal pressure, but would allow a FS launch. Although maybe not the best solution for water use. A couple vents mid canopy may take lots of water when a wave crashes over your kite. Tim's solution (closing best part of the velcro) is the easiest IMO. IF you experience this problem in the first place. First step for me would always be: add talcum to the socks to avoid them stick together. Goes a long way.

And another thing: you might find lots of air escaping when you blow your kite up with a leaf blower. In flight, things are different. The internal pressure in flight is nowhere near your blower's capacity. If I'm not mistaken, it's around 1/10,000 of the athmospheric pressure. really really small. I haven't checked this myself, Mr. Lynn Sen. says that in one of his papers. Remember, where we use kites (pressure, velocity...), air is regarded in the models as a fluidum. Can't compress it. Like water. Now here begins the tl;dr stuff :D
tungsten
 
Posts: 483
Joined: March 22nd, 2010, 8:19 am

Re: Internal Pressure Test on Chargers...

Postby Albatross Mark » March 17th, 2012, 9:48 am

Gonna lay out Ch 15 and P4 15 Flysurfer and measure Vents and placement. Flysurfers have way more vent area and fly well and launch so easy. Yeah they have bridal but stil allota vent doesnt stop them from flyin?And Flysurfer knows alot more than VO thats for sure and certainly care about their quality.If it wasnt better they wouldnt use it.You can belive Flysurfer wants to build the best kite they can. VO and many kite brands dont have that. Fortunately there are companies like North and Flysurfer that are making the best they can and what a pleasure to fly!
Albatross is a huge seabird that soars the waves and winds of the high seas mostly in the roarimg 40's. Albatross Mark tries to mimmic this bird using the following kites: 8m Vortex,10m Venom,8m P3 FS,10m North Rebel ,10,12,15, 19m Psycho 4 FlySurfer
Albatross Mark
 
Posts: 464
Joined: June 25th, 2010, 7:36 am

Re: Internal Pressure Test on Chargers...

Postby Timothy Grossnickle » March 17th, 2012, 11:08 am

Mark,

For what its worth have done several days in a row on Ch 19 with velcro tabs closed in relatively low wind sea breeze 12/18 mph. Given that air intakes on both Ch 15 and 19 roughly the same size, had no trouble at all inflating the Ch 19 or keeping it inflated while working the kite hard on the water.

Another thing to consider is air ESCAPING through the intakes. When we pressure tested the Ch 15 and 19 it surprised me to find air ESCAPING through the intake vents. Needless to say at Tungsten pointed out the a leaf blower or shop vac will generate far more pressure than a arc in flight. However, I think that when you work an arc hard you are squeezing some of the air out of the kite which gets replaced through the vents when you reduce the turning pressure. While I'm theorizing here, I do think that the Lynn's and later the VO designers realized this and over time reduced the size of the intakes thinking they could reduce the loss in pressure squeezing the kite while turning the kite by reducing the size of the vents.

As to why FS uses more vents than VO, IMHO FS bridled FS kites rely far less on internal pressure than bridleless Arcs because when you yank on a FS kite the bridles distribute the pressure evenly across the kite. Bridleless Arcs on the other hand rely on internal pressure to stiffen the kite and make it turn. As we have all experienced in launching Arcs under inflated kites become difficult to control and turn. Therefore I would propose that while FS kites inflate quickly due to the larger intake space, they also deflate faster through these same vents. As evidence of this I've seen in person and on YouTube experts "pre inflating" FS kites and watch them deflate almost as fast as the inflation. In this regard, assuming these FS kites didn't suffer from skin leaks the pressure loss could only have come through the air intake vents.

In closing, before you cut up a Syn and a Ch, you might want to pressure test both kites and get a sense for how much air ESCAPES through the vents when you put pressure on the kite turning it.

Regards,
Tim
Timothy Grossnickle
 
Posts: 162
Joined: January 14th, 2012, 11:51 pm

Re: Internal Pressure Test on Chargers...

Postby Hardwater Kiter » March 17th, 2012, 12:24 pm

True, mid chord vents wouldn't help the internal pressure. They would be a matter of launch convenience.

For what it's worth we messed around with restricting vents on Arcs to see the effects. Once the wing is up to flyable internal pressure we were able to fly Syns, Scorps V2's with only one vent. Maintaining pressure wasn't an issue, it's getting pressure that was hard.

The Scorp bleeds air like crazy. As a "land based" Arc I can only imagine they left out a step in production that allows for better use on water.
"The rider makes the kite."
Owner/instructor @ http://www.hardwaterkiter.com
User avatar
Hardwater Kiter
 
Posts: 353
Joined: July 8th, 2010, 3:39 pm
Location: Cow Hampshire

Re: Internal Pressure Test on Chargers...

Postby Flyboy » March 17th, 2012, 4:02 pm

Tim, Dr Tungsten and Hardwater,
You guys are 1000% correct.
Mark cut away! But read this:

http://www.swing.de/index.php?main=entw ... ra&lang=en

"During normal flight conditions there is no loss of dynamic pressure if the cell openings are positioned well, which means we can almost consider our canopy as closed. "

IMO airflow inside the wing inflight is absurdly low and as these guys said can be accomplished with one opening.
The only time air is flowing in is probably due to low porosity (or as Tim has found through the velcro - Which Tim, I'm hopeing to check my Synergies today) (or also in paragliders steep spiral turns)
The only reason that paragliders, and snow kites are open cell is full deflation on launch and land. and I'm assuming the only reason Flysurfer has more vents is to allow for paraglider type launch.

It's cool bro, cut away! I'm gonna start planning a vacation to Spain!

http://www.youtube.com/watch?v=WUnxcuQLsS0

This is specifically for Dr. Tungsten:
http://www.gliderengineering.com/labora ... ty.en.html
Flyboy
 
Posts: 94
Joined: September 15th, 2011, 3:47 pm

Re: Internal Pressure Test on Chargers...

Postby tungsten » March 17th, 2012, 5:02 pm

Flyboy, thanks for the flowers, but I never made my PhD. I'm working on fins and boards right now, maybe there's some worthy subject for that. But I don't think so 8-) .

Interesting links. I got this sorted a while ago when I was dealing with leaking sun bleached kites. Problem is, the kite fabric is coated with a PU coating which wears off with time. What really works is Nikwax tent & gear proof, makes your kite amazingly water & air tight, BUT, this stuff also makes the seams & fabric repellent to any glue up to 3M spinnaker tape. Kind of softens it up as well. So for repairs, you will have to fire up the sewing machine in the future. But it's amazing stuff, for old kites a must. Gives another 200 sessions of life to an old leaking rag. And affordable.

You're a pilot mate, so yeah, I assume you went through the thick parts of fluid dynamics. I worked my way through it as well, problem is, with a rather flexible and uneven wing like an ARC there's less calculation and more guesswork / trial & error involved. But hey, as long as we're able to come up with results it's all fine and I praise that hobby. And let me say this: I have utmost respect for guys like Pepijn who design that stuff on a commercial level. Tinkering is one thing, but putting out a product is another.

HK, I thought so. I was thinking about trying different materials for the sock, but at the end of the day never came around doing anything about it. I got good results with the mods on SYN and CH which made me happy enough to call it a result and go kiting.
tungsten
 
Posts: 483
Joined: March 22nd, 2010, 8:19 am

Re: Internal Pressure Test on Chargers...

Postby Flyboy » March 17th, 2012, 8:25 pm

Dr. Tungsten, it's cool bro, your secret is good with me! Fist time I cheated was third grade. :o

Tim, I just pumped up my kites! It's kinda scary at first. You think they're gonna pop! Your right on track though. The Velcro drains leak badly. I taped them up on my 15 Syn and it holds pressure noticeably longer. Then I did the same with a 10 m venom. They still leak, taped them up but it holds pressure just a bit longer. Noticeable, but not as drastic. I can't wait to try them though. I'm working for a few more days so won't be able to post updates too soon.
Flyboy
 
Posts: 94
Joined: September 15th, 2011, 3:47 pm

Re: Internal Pressure Test on Chargers...

Postby Timothy Grossnickle » March 17th, 2012, 11:52 pm

Flyboy,

Appreciate the information on the internal pressure of paragliders, but IMHO you can't equate bridled foil wings like paragliders and FS kites to Arcs with no bridles. When you turn a bridled kite you aren't relying on the internal pressure of the kite for stiffness as with Arc's. IMHO bridled kites can operate with open cells because they need far less pressure. I have one FS and to me it operates the same as the open celled 4.9 m Blade kite I use on ice and snow. The air flows easily in and out on the FS as it does on the Blade.

None the less I'm glad you tested your 15m Syn noticing the same sort of things as me concerning the velcro tabs leaking air. Until today I harbored some concerns about how the CH 15 and 19 would react when crashed in the water. Today I found out.... Blew a jump with Ch 19 and slammed the kite hard under full power nose down in 5 foot rollers in the Gulf of Mexico. Have to say the kite relaunched easier than any PLK Arc I've owned. With the velcro tabs closed the CH 19 rolled over almost on its own and with one tug of the top lines shot back up to zenith. The relauch took less 20 seconds. Once in the air the water poured out of the 90% closed velcro tabs and from the stitching in the tail of the kite. I would say the water drain took 15 second and probably less.

Think the CH 19 not losing pressure when it crashed meant it took in less water than with the velcro tabs not taped. That the water drained out so quickly tells me that taping them over doesn't materially affect the water drainage. The only downside to this without the release of pressure through the velcro tabs could increase the danger of the Chargers blowing out seams. However, given my difficulties in re-launching the Ch 15 after its many crashes with the velcro tabs not taped shut I would rather risk a blown seam than a hand clapping hard to re-launch Ch 15....

Regards,
Tim
Timothy Grossnickle
 
Posts: 162
Joined: January 14th, 2012, 11:51 pm

Re: Internal Pressure Test on Chargers...

Postby arcspearo » March 18th, 2012, 12:36 am

Another soul-session in Hatteras. Tungsten Bridle/mid strap tucked Blue CH15 worked kite a charm.
@Mark- for all the pain she's given you...
you 'aint got a hair on your a** if you don't cut into her with bright lights and cold steel!
Good things come to those who wait? No. Good things come to those who work their tails off and never give up.
arcspearo
 
Posts: 41
Joined: August 30th, 2010, 11:25 pm
Location: Pensacola

Re: Internal Pressure Test on Chargers...

Postby Ced » March 18th, 2012, 12:36 pm

Have to agree with Tim on the bridle vs non bridled issues. A flysurfer and an arc are very different animals. I don't think you can apply any of the vent engineering of the Flysurfers to Arcs.
Maybe a bridle on arcs, but it's been tried and kind of defeats the purpose.

Ced
Peter Lynn Team Rider
www.cannonrocks.com/Kiting.html
User avatar
Ced
 
Posts: 165
Joined: February 3rd, 2010, 4:38 pm
Location: World

Re: Internal Pressure Test on Chargers...

Postby Albatross Mark » March 19th, 2012, 6:45 pm

Sat down to put two vents in and wind was picking up.Felt rushed so decided to just put one in . Put it between the two existing vents. Put it about 3 inches down onto the inner skin thinking this will help inflation on launches. Wind was too light so used P4 15. Standing by for 18 plus knots.Have been able to do Quick Clam launches on all Arcs except Charger.Hope the New middle vent mod will make them easy.And maybe more stability in flight?
Albatross is a huge seabird that soars the waves and winds of the high seas mostly in the roarimg 40's. Albatross Mark tries to mimmic this bird using the following kites: 8m Vortex,10m Venom,8m P3 FS,10m North Rebel ,10,12,15, 19m Psycho 4 FlySurfer
Albatross Mark
 
Posts: 464
Joined: June 25th, 2010, 7:36 am

Re: Internal Pressure Test on Chargers...

Postby Albatross Mark » March 20th, 2012, 7:23 am

Middle vent was a success. First time launched from my quick clam launch with about 80% inflation . Then kite opened up in hot launch and filled slowly and rose slowly like FS.First time quick launch on only Arc that untill moded would not Quick launch for me .It had to be 97% full in regular launching before mod.The three inches down offset i believe made it fill faster in hot launch position. Still after Tungsten mod of 5 cm(2 inches) on the inner strap the kite turns fast but feels out of control in that a littlle input seems to get manified starts turning too much so I feel the Charger 15m and. 19 m are whacky untameable kites.Sure you could eventually learn to handle them but to me they are a kite i will go to last resort for conditions where i may lose a worthwhile expensive kite.Or sell my Charger 15. Put up my Synergy 15 later and she handles so obediently.This really has shown me Charger 15 is No good to me.Bar pressure on both arcs was heavy and needed both hands all the time. Went back to my P4 15 FS and got way more power and controlled with one hand most of the time with perfect bar pressure.I will trade the modded Charger 15 for a Synergy 12.Dont really want to fly Pls in 15 or larger. The FS15, North Rebel10 and a 10Venom are my favorite kites Now.And cover light,Medium and strong gusty the best.got plenty of kites for sale tubes and arcs. Call me 808-634-6104,
Albatross is a huge seabird that soars the waves and winds of the high seas mostly in the roarimg 40's. Albatross Mark tries to mimmic this bird using the following kites: 8m Vortex,10m Venom,8m P3 FS,10m North Rebel ,10,12,15, 19m Psycho 4 FlySurfer
Albatross Mark
 
Posts: 464
Joined: June 25th, 2010, 7:36 am

Re: Internal Pressure Test on Chargers...

Postby Flyboy » March 20th, 2012, 3:05 pm

Mark,
Let's talk. You KNOW you want my 15 Syn! Just let me try the beast!
Flyboy
 
Posts: 94
Joined: September 15th, 2011, 3:47 pm

Re: Internal Pressure Test on Chargers...

Postby Timothy Grossnickle » March 20th, 2012, 7:20 pm

Mark,

Applaud your persistence in adding vent to Ch 15. Interesting the differences in the kites. My Ch 15 very sensitive to bar inputs and prone to collapsing like yours even with the 5 cm middle strap tuck.....although less so with velcro tabs tapes shut. However Ch 19 has yet to collapse and flies with the stability of my Syn's or Venoms.

Do have a suggestion for the bar pressure issues with Chargers, which I experienced with both Ch 15 and 19. At the suggestion from someone on this forum I added about 6" to the bottom pig tail. Attached the flying lines to the last knot in the top and on the bottom and the bar pressure issues went away. Now both kites fly with about the same bar pressure as other PLK Arcs.

Its also worth noting with your control issues that the VO designers have abandoned the Charger type bridle on new P2 as well as offering the option of a fixed bridle. Others on this forum are flying the smaller Chargers in gusty conditions with fixed bridles. In fact, while I like the current charger bridle setup, and fly in mostly steady winds, I can appreciate your comments and of others that the Charger bridles make for difficult handling in gusts. In this regard, as you mention you like your V 10 as I love my V1 13 in gusty condition, I'm wondering if it would make sense for you to try a fixed bridle on your Chargers...

Regards,
Tim
Timothy Grossnickle
 
Posts: 162
Joined: January 14th, 2012, 11:51 pm

Re: Internal Pressure Test on Chargers...

Postby Kamikuza » March 21st, 2012, 1:28 am

Albatross Mark wrote:Flysurfers have way more vent area and fly well and launch so easy.

You're making an erroneous conclusion there - more vents is not why Flysurfers fly and launch well... it's cos they're supported by an extensive bridle system.
User avatar
Kamikuza
 
Posts: 297
Joined: June 25th, 2010, 12:08 am
Location: Japan

Re: Internal Pressure Test on Chargers...

Postby Albatross Mark » March 21st, 2012, 7:01 pm

Yes the bridal allows easier launching.But i HAVE in my mind confirmed proof that Charger 15 and 19 were NOT engineered and designed properly.They launch much easier with the middle vent Mod and and sure it wouldnt hurt the smaller ones to launch easier.The Tungsten strap mod did help tame her some BUT didnt stop the "veering",Even with NO bridal and direct steering like older models the "veering" sucks to me."Veering" is like when you put your flat hand into the wind out a car window at speed a slight turn up or down wants to accellerate a turn.I hate that response in the Charger as you need to give the kite a counteractive input to correct it and if you dont it may crash on you. NO THANKS too complex of flying . I want to focus on surfing and jumps NOT controlling a wild beast.I like Synergies etc.as they are obedient servants. Psycho 4 Flysurfers are so much sweeter in light to medium light winds.Supreme control with light one hand flying and half again more power in the same sizes.But for strong gusty 8 -12 m Arcs are my favorite.
Albatross is a huge seabird that soars the waves and winds of the high seas mostly in the roarimg 40's. Albatross Mark tries to mimmic this bird using the following kites: 8m Vortex,10m Venom,8m P3 FS,10m North Rebel ,10,12,15, 19m Psycho 4 FlySurfer
Albatross Mark
 
Posts: 464
Joined: June 25th, 2010, 7:36 am

PreviousNext

Return to On the Water

Who is online

Users browsing this forum: No registered users and 2 guests

cron