Lines for Rokkaku

James Chan (jchan@herman.cs.uoguelph.ca) wrote:
: Hello R.K reader,
: Here  are my questions.  1) I am building Maxwell Eden's KaleidaKite.  It 
: requires 150' Dacron line.  I was wondering what kind of pull it generates
: on a 8-12 mph wind condition.  I know I have to wear gloves; but I wonder 
: if I can fly this kite by myself.
: 2) I am also planning to build a Rokkaku kite.  With the ratio of 6:5:4
: in mind, if I build a 10 foot kite (at the first dimension), can I fly
: this thing by myself?  How do I calculate what line strength is required?
: What is the limit when a Rokkaku kite requires more than one person to
: fly it?
: Thanks in advance.
: *james*

I have been able to extend the upper limit at which I can fly my
6'4" x 4'9" rokkaku (approx 25 square feet) by using a piece of
climbing hardware called a figure 8 descender, which is used for
belaying.  The line goes through the figure 8 in a lark's head
configuration, and the pull is significantly reduced.  I've flown
the kite alone in 30+ mph winds this year, using this device.

One point:  I can't pull the kite in at wind speeds above ?20? mph,
so if the wind is high, I have to find flying locations where I
can walk the kite down.  A carabiner is useful for walking the kite
down (just open the biner, clip over line, walk -- a strap on the
biner makes it easier).

You should be able to fly the Kaleidakite yourself, but it might 
be more fun (= less stressful :-) to have another person around
for the first flight -- first flights for my large kites are usually
with my husband (who considers bridle tweaking the most interesting
part of kite flying) or down at the park when I know other kite
flyers will be there.

A rule of thumb for determining what strength line to use is that
the line should be *at least* 3 times (in pounds) the lifting surface
of the kite.  The higher the wind, the higher the multiplier should
be, but I don't know how to quantify it <grin> although Jeff Burka
would say if the line broke, it wasn't strong enough.  I think he's
saying experience counts for a lot.

I sometimes look at a catalogue like Into the Wind's for suggestions
on what kite line to use.....

If the kite has an adjustable bridle, you can moderate the pull by
setting the bridle on the side of lift rather than pull within the
range of stable flight.

If you want to measure pull after you've made the kite, hook a small
spring scale into the kite line (lark's head a ring onto the line
and hook the scale to the ring).

I am usually flying the rokkaku in order to lift  3-4 pounds of
camera and radio control equipment and have rarely flown it in
winds less than 12-14 mph, on 250# line.  Occasionally I use 450#
line.  Both considerably more than 3 x area of kite (which would
be 75 pound line!).

BTW, you might want to put your name and phone number on your kite,
something I keep meaning to do, especially the day I watched the
450# line stretch in those 30 mph winds.

I think you will be challenged flying your rokkaku by yourself without
something like the figure 8 descender *if* you start exploring flight
in winds in the upper teens, low twenties (depending on how strong you
are).  You may also want to think about how many bridle points and
selectively reinforcing spars (a friend, Lee Thrall, has an 8.5'x11'
rokkaku, which he's flown on 5 point bridle up to 25 mph; the spine
is .505 fiberglass in 3 pieces, with a piece of thick wall .411 
running inside the center piece and extending as long ferrules
into the two end pieces).

Hope this helps.


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 *  Anne Rock                  |                                           *
 *  Berkeley, California       |                                           *
 *  rock@netcom.com            |                                           *
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