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Wind and Stacks


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#1 West Australian

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Posted 07 March 2013 - 03:53 PM

There is probably no simple answer...

How does Stacking Rev's affect their min/max wind?

 

I have been playing around with combinations of my VTD, MID and STD B series.

In a few winds I have felt it was getting a bit light for the VTD at the front.

 

And a couple of times it felt like it was getting too strong for the STD at the back.

 

I dont have enough kites to do a stack of all the same type.

But I am interested in finding out about them too.

 

So what are your stack experiences?

What stack physics can you share?

 

WA


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#2 monkey

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Posted 07 March 2013 - 04:21 PM

One thing to bear in mind with this, it's the front kite thats going to make the biggest difference. I get the problem of not having enough of the various types, but, also bear in mind that the different sails do move at different speeds under a similar wind load, so ideally, all the same variety or you'll end up with a jumpy stack.


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#3 West Australian

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Posted 07 March 2013 - 06:43 PM

Thanks for the response.

 

I have noticed the back kite overshooting sometimes.

I have been tempted to reduce the length of the brake line a bit (by putting in a knot) and see what happens.

 

I need to make do with a variable vented stack.

 

Do you find a stack needs more/less wind than a single kite?


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#4 RevWizard

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Posted 07 March 2013 - 07:59 PM

Less wind is required for a stack

For the wobble of the last kite, check that all the stack lines to the last kite are the same length within a couple mm.

Some stack fliers also like to have the the bottom two stack lines, if I recall correctly, slightly longer. It is mention in several threads on this forum more precisely how much more(or less).


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#5 SparkieRob

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Posted 07 March 2013 - 08:07 PM

Less wind is required for a stack<br />For the wobble of the last kite, check that all the stack lines to the last kite are the same length within a couple mm.<br />Some stack fliers also like to have the the bottom two stack lines, if I recall correctly, slightly longer. It is mention in several threads on this forum more precisely how much more(or less).
Yep, bottom two link lines a touch shorter. Stacks are more efficient with the wind as they divide the forces between them. I've found that directly down wind they get a little jumpy cause of wind shadow? but just off centre they are lethal! I don't think a stack of less sail area to more sail area would be as sensitive dead centre as some of the wind is venting through. <br /><br />YMMV as I have only dabbled in stacks. <br /><br /><br />Sent from my iPhone using Tapatalk

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#6 SparkieRob

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Posted 07 March 2013 - 08:10 PM

One thing to bear in mind with this, it's the front kite thats going to make the biggest difference. I get the problem of not having enough of the various types, but, also bear in mind that the different sails do move at different speeds under a similar wind load, so ideally, all the same variety or you'll end up with a jumpy stack.
I thought that you would want the back kite to travel faster than the front as it has a greater distance to cover given that they move in an arc. Or does it not matter that much as there is about 4.5 feet between kites?<br /><br /><br />Sent from my iPhone using Tapatalk

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#7 kwmf

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Posted 07 March 2013 - 11:16 PM

I think you want the back one a little slower because thats the one that overshoots and causes the wobble effect ... also slowing it down a bit will mean the forward ones need to drag it along a bit which results in more tension and 'locked-in-ness' down the stack.

 

Well thats my ASSumptions anyway, I know I prefer it with slightly shorter brake links on the rear kite ... but I'm only flying a B2 set stack.



#8 stevepigeon

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Posted 08 March 2013 - 07:31 AM

i have a eight stack same kites and on kite #5 1/4 inch shorter bottom # 6 was 1/2 shorter then 3/4 and 7/ 8 on the last that works best for me i dont know how on a stack with standard and mid vent and vented would be because each kite in same wind will have different speed when flys if vented  are in front i would think more forward top line shorter then mid alittle longer and so on just my two cents


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#9 REVflyer

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Posted 08 March 2013 - 12:13 PM

if you want less pull, then lengthen the bottom train lines (slightly), = big-sail sized stack

 

if you want it slower and more brake available during flying, then SHORTEN the bottom train lines = mini-rev stacks

 

(each of these directions is a micro adjustment, hence the reason most folks leave the stack together after tuning)

 

Steve's stack features is a progressive shorting of the train lines!,... you can bet those dimensions weren't arrived at during the initial 15 minutes of first testing!



#10 West Australian

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Posted 11 March 2013 - 06:24 PM

Thanks for your Input guys,
Sounds like I am up for a bit of experimentation.

 

I am concerned that the STD at the rear is sometimes getting too much wind when flying with it's vented cousins.

I guess I will play it by ear.


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Supersonic and 1.5 Ghost SUL too


#11 REVflyer

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Posted 12 March 2013 - 03:05 AM

you have to fly the back kite,.... the others are just in the way of your completely focused vision



#12 West Australian

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Posted 12 March 2013 - 11:08 PM

Actually I remember that advice from my duallie days too.

 

Thanks Bro


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#13 West Australian

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Posted 26 March 2013 - 08:32 PM

I have been contemplating extending my Progressively Vented Stack.

I have A Full Vent - Mid Vent -  Standard as my setup.

 

Any advice on choosing the Vented level of the next kite?


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#14 SparkieRob

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Posted 26 March 2013 - 09:14 PM

I have been contemplating extending my Progressively Vented Stack.<br />I have A Full Vent - Mid Vent - Standard as my setup.<br /> <br />Any advice on choosing the Vented level of the next kite?<br />

 

XTRA or Polo VTD. They will extend your wind range even further.

 

OR

 

Get another B Vented and some scissors.....

 

Help yourself to my Polo next time!


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#15 West Australian

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Posted 26 March 2013 - 11:00 PM

Ok so the Xtra and Polo VTD are a good idea, the Scissors not so much.

 

Higher cost though. Really wish there was a Production Run XTRA.


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#16 SparkieRob

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Posted 27 March 2013 - 12:08 AM

There is another couple of options; A Shook mesh but I'm not quite sure which way the %'s work, or a full sail with "soldering iron vent holes". There is a fair bit of info on it in the bowels here!

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#17 stroke survivor

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Posted 27 March 2013 - 08:17 AM

There is another couple of options; A Shook mesh but I'm not quite sure which way the %'s work, or a full sail with "soldering iron vent holes". There is a fair bit of info on it in the bowels here!

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#18 West Australian

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Posted 27 March 2013 - 05:14 PM

I honestly dont think I could cut holes into a Rev. Or any kite really.

 

I was more thinking of adding in more of the same.

Another VTD on the Front, or a second MID. Perhaps even another STD.


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Supersonic and 1.5 Ghost SUL too


#19 SparkieRob

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Posted 27 March 2013 - 06:28 PM

Better to spend a bit more on a kite that will extend your wind range than simply another one of what you have already. XTRA will compliment your colours already as it has the same sail pattern. Maybe you could play on the Colourizer and incorporate the colours and create one "super kite"!

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#20 SparkieRob

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Posted 27 March 2013 - 07:24 PM

Some quick ones...ImageUploadedByTapatalk1364441023.195026.jpg ImageUploadedByTapatalk1364441038.274370.jpg

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