Diamond Kite Problem

[MARK Crothers]

Hi Folks,

I've been reading this group for a few months now and most of the
discussion seems to concern power kites so this question might seem
a little out dated, but here goes:

I've got a single line, traditional-shape diamond kite which basically
refuses to fly. It gets a few metres into the sky and then goes into a
terminal spin - it loops around in very tight circles and eventually
crashes. This happens every time I try to fly it.

I've tried moving the bridle attachment point both closer to, and away
from the top but it doesn't make any difference - same spinning, same
crashing.

The tail consists of three light pieces of ribbon streamer - does this
need to be heavier/lighter?

This isn't a home-made job - I bought it for my son, so any help you
could provide would be much appreciated by both him and myself.

Thanks,

Mark Crothers
B.T.
Belfast Software Engineering Centre
Northern Ireland

mcro...@bfsec.bt.co.uk

[Marty Sasaki]

In article <D3Kp0...@bfsec.bt.co.uk>, mcro...@bfsec.bt.co.uk (MARK Crothers) writes:
|>I've been reading this group for a few months now and most of the
|>discussion seems to concern power kites so this question might seem
|>a little out dated, but here goes:

Folks should feel free to ask or start a discussion about any type of
kite or kite related activity. Please don't be intimidated. If it is
about kites, we should talk about it here on rec.kites.

|>I've got a single line, traditional-shape diamond kite which basically
|>refuses to fly. It gets a few metres into the sky and then goes into a
|>terminal spin - it loops around in very tight circles and eventually
|>crashes. This happens every time I try to fly it.

Does this kite have a bow string or is it flat? If it has a bow
string, then you need to increase the bow by shortening the string. If
the kite is flat, then add more drag with more tail.

|>I've tried moving the bridle attachment point both closer to, and away
|>from the top but it doesn't make any difference - same spinning, same
|>crashing.

If you remember where it was, put the bridle back to where it was
before you started your experimentation. Once you get the spinning
under control, try moving the bridle up and down (in small amounts) to
see how the kite responds. Generaly, moving it down will make the kite
more lively, it will tend to move around a bit. Moving it up will make
it steadier.

|>The tail consists of three light pieces of ribbon streamer - does this
|>need to be heavier/lighter?

With tails, it isn't so much the weight, but the drag that is
important. Ribbon streamers don't add much drag. The old bed sheet
cloth tails are actually pretty good about providing drag.

One last thing, make sure that the cross stick is on the back side of
the kite...

--
Marty Sasaki Harvard University Sasaki Kite Fabrications
sas...@harvard.edu Network Services Division 90 Melrose Street
617-496-4320 10 Ware Street Arlington, MA 02174
Cambridge, MA 02138-4002 phone/fax: 617-646-1925

[Donald Qualls]

In <D3Kp0...@bfsec.bt.co.uk> mcro...@bfsec.bt.co.uk (MARK Crothers)
writes:

>
>
>Hi Folks,
>
>I've been reading this group for a few months now and most of the
>discussion seems to concern power kites so this question might seem
>a little out dated, but here goes:
>
>I've got a single line, traditional-shape diamond kite which basically
>refuses to fly. It gets a few metres into the sky and then goes into a
>terminal spin - it loops around in very tight circles and eventually
>crashes. This happens every time I try to fly it.
>
>I've tried moving the bridle attachment point both closer to, and away
>from the top but it doesn't make any difference - same spinning, same
>crashing.
>
>The tail consists of three light pieces of ribbon streamer - does this
>need to be heavier/lighter?
>
>This isn't a home-made job - I bought it for my son, so any help you
>could provide would be much appreciated by both him and myself.
>

I've had similar problem with those in the past. There are two basic
things that can be done. First, as you guessed, is a longer, heavier
tail. This won't completely cure the problem, as the kite will still
cant over toward the side it now spins to, but it might let you fly it
in brisk winds.

The other thing is to examine the sail for assymetry. My guess is that
you have more tension in one side than the other, causing the lift to
differ. Assuming this is a commercial paper-covered diamond, you may be
able to improve this by sliding the bottom (the bottom is the bigger
offender) of the spine >toward< the side it spins to -- this will
increase the tension on that portion of the sail, and decrease it on the
other, and should improve the situation. If it does, or if the kite
starts spinning the other way, you can then fine-tune things to get a
reasonably stable flight.

Another thing that might help is to increase the bow of the cross stick,
by tying on a tensioning string. I used to fly these with about 3-5 cm
clearance between the bow string and the cross stick; at that setting,
and with a little careful spine adjustment, they frequently needed no
tail at all!
--
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+----------------------------------------------------------------------+

[Andrew Beattie]

>If you remember where it was, put the bridle back to where it was
>before you started your experimentation.

Yep. Look closely at the bridle-line. You might be lucky - there might be a
mark showing where the middle of the knot should be.

Andrew
--
Does a Rev War Kite have 4 lines and fly on Manja? o /\ Kite Jumping:
Read the Kite FAQ's: ftp.hawaii.edu:/pub/rec/kites/faq |_ \/ If you want
For sale: Prototype Keelless Rowlands Flowform. US$80 (_\ to fly, use a
Kite Fliers Site: http://www.kfs.org/kites and...@tug.com Hangglider

[Harry Gregory / Nancy Lockwood 71224,221]

Your first problem is the BRIDLE. I'd bet it's too short. The
top leg should stand away from the body of the kite at LEAST as
far as from the center to the outer wing edge, if it's shorter
than that, spin is inevitable. Second, lengthen the tail, do NOT
make it heavier, make it longer. Length stabilizes the kite, and
you might try David Pelham's "rule of thumb": 7x width of kite.
Is this a Decorator kite made of heavy taffeta with a zoomy
design on it? They weren't really made to fly, and are usually
not properly proportioned. A really GOOD diamond kite can be
structured quite easily, making it AS WIDE AS IT IS TALL, and
positioning the cross spar 1/5th of the distance from the top.
Cover with a sail made of anything, and if it's balanced right,
you won't even need a tail. Someone mentioned bow string. It
helps. Putting a bow in the sail gives it dihedral.
Good luck !
Fly free ! Nancy

--
I'am Just Down The line.

[MARK Crothers]

Thanks to all who replied to my request for help with an uncontrollable
diamond kite.

Most of the responses recommended a tail with much more drag than the
original multi sreamer/ribbon affair. I attached a 5 metre tail from an
old stunt kite, planning to cut this down if it proved too heavy for
the diamond. I tried it out on Sunday and the kite flew beautifully !!!

Thanks again,

Mark

P.S. The diamond is now my son's "favourite" - praise indeed.

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