Subject: article forwarded from mail
From: "Brunyee, J, Jannine" <[email-masked]>
Date: Thu, 23 Nov 1995 18:00:23 -1000

I hope some one out there can help me.

I am an MBA student at the Graduate School of Business at the 
University of Cape Town and am doing a technology analysis on kites 
for a course on The Management of Technology.

A key component of this paper is tracking technological change over 
time - on a graph. The idea is to plot s-curves. Does any one have 
any hard data on improvements in materials over time. Probably the 
easiest thing to measure would be weight.

I would greatly appreciate any help and would, of course, be willing 
to send a copy of the report to you in return.

Thanks

Janinne Brunyee

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Date:	Fri, 24 Nov 1995 21:42:42 -1000
From:	[email-masked] (Andrew Beattie)
Message-Id: <[email-masked]>
Organization: /usr/lib/news/organisation
Subject: Re: article forwarded from mail

"Brunyee, J, Jannine" <[email-masked]> writes:
>I hope some one out there can help me.
It's normaly considered poor form to post an article that says "I'm
writing my thesis, would someone like to do my research for me?", but
I'll let you off...

>A key component of this paper is tracking technological change over 
>time - on a graph. The idea is to plot s-curves. Does any one have 
>any hard data on improvements in materials over time. Probably the 
>easiest thing to measure would be weight.
Plotting the weight of the kites would be somewhat meaningless.  Things
that might be interesting include:

Wing-loading.  (The term may me inaccurate).  By this I mean weight/area.
I have no historic data for this.  I build soft kites with a figure of
around 96g/m^2.  You'll find much lower figures from the guys who build
sub-inch micro-kites.

Spar stiffness.  There is a lot of carefuly researched info on the stiffness
of spars.  Look for a pointer at http://www.kfs.org/kites.  All you need
to do is to find out the date of introduction of the sticks.  Hmmm...
I think that they cover only carbon and GRP.  You may want data for various
sizes of dowel and banboo.  You may care to research this yourself and send
the data back to the maintainers of the stiffness chart.

Lift-to Drag.  I have no data, but it's easy to research - you can measure
it directly.  It's the tan() of something.  (Last time I posted a formula
>From memory, I screwed up, so you can work it our for yourself...)

Minimum windspeed required.  There is some data available on this subject,
but it's all lies :-)

>I would greatly appreciate any help and would, of course, be willing 
>to send a copy of the report to you in return.

Post it to rec.kites.

Andrew
-- 
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Next time you visit KFS, download the bookmark file.

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Date:	Sat, 25 Nov 1995 16:14:47 -1000
From:	[email-masked] (Mark de Roussier)
Message-Id: <[email-masked]>
Organization: damage
Subject: Re: article forwarded from mail

"Brunyee, J, Jannine" <[email-masked]> wrote:

>A key component of this paper is tracking technological change over 
>time - on a graph. The idea is to plot s-curves. Does any one have 
>any hard data on improvements in materials over time. Probably the 
>easiest thing to measure would be weight.
>

Hmmm. I suppose I have a number of reactions to this :

1. No - I don't know of any such database.

 Dave Lord/ Simo Salanne / Michael Graves have amassed a worthy
collection of data about spars of various sorts, available at
http://www.kfs.org/kites/Specs/index.html . But this does not contain
the temporal information you need ( although you might be able to
screw this out of the manufacturers ).

Most kite making materials that have ever been used are still around
somewhere, if you're willing and able to find them and make the
measurements yourself - but you'd still have to sort out your time
axis .

2. Perhaps the reason for 1. is that forming one is tricky.

For instance, what do you call a 'material' ? To get enough data
points for a useful plot, you must concern yourself with details,
otherwise you would, in the case of spars,  have only five points -
wood, bamboo, aluminium, fibreglass and carbon. And you might have
problems ordering those in time.  The situation is similar for sail
materials and line. 

Besides, just plotting weight is no good - weight of what ?  Do you
actually mean density ?  Weight per unit length ? In these measures,
how do you treat tubes vs solid rods ?  Or do you mean strength to
weight ratio ( however you define strength ) ? Lets assume you mean
strength to weight ( although this ignores another crucially important
measure, namely stiffness to weight ). 

How are you going treat the effects of design vs material ? i.e. it
could be argued that all carbon spars were the same *material* - it
was the techniques of construction that distinguished them. So if you
had the data, your plot would not measure improvements in materials
per se, but in the techniques for employing them. Or, more probably
and problematically, a combination of improvements in base materials
and improvements in design.

And lets go back to the issue of the measure to use. If you were to
use strength to weight, you might find progress following a different
path, perhaps slowing sooner, than if you used stiffness to weight. If
you were to use some form of composite index, what would guide your
choice of method for combining the components of that index  e.g. how
would you weight the stiffness measure vs the strength measure ?

Despite my apparent skepticism (:)), I would be interested to know
what conclusions you come to.

--------------------------------------------------------------------------------
                ************************************
                Final thoughts, as breath is taken,
                Fall to rhythm, and the
                Edge of pure obsession,
                Resting in the wind blown cradle,
                Nothing moves, the world is still...
                ************************************

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Date:	Sun, 17 Dec 1995 14:00:00 -1000
From:	[email-masked]
Message-Id: <[email-masked]>
Organization: Division of Applied Sciences, Harvard University
Subject: article forwarded from mail

Subject: Kitefliers in Mexico

Greetings -

We have a request for information about kitefliers, kiteflying
sites, and kites stores in the Guadalajara, Mexico, area.  If
you have any ideas or knowledge, please let us know either via
rec.kites or [email-masked].

Happy Holidays!!!

Mel Hickman
AKA XD

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Date:	Mon, 22 Jan 1996 14:00:00 -1000
From:	[email-masked]
Message-Id: <[email-masked]>
Organization: Division of Applied Sciences, Harvard University
Subject: article forwarded from mail

Greetings -

Does anyone have an up-to-date address for Stephane
Marquis of Switzerland?

TIA!

Mel Hickman
AKA XD

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Date:	Tue, 30 Jan 1996 09:39:55 -1000
From:	Bay Area Sport Kite League <[email-masked]>
Message-Id: <[email-masked]>
Organization: Division of Applied Sciences, Harvard University
Subject: article forwarded from mail

Bob Steele asks "When does BASKL start up this year?"

Here is the unofficial 1996 schedule for the Bay Area Sport Kite League
(BASKL).  It's unofficial because some of the parks have not confirmed
availability of the dates as yet.

        When            Where           In Coordination with...
        ----            -----           -----------------------
        April 13        Berkeley
        May 19 (sunday) Tracy           City of Tracy and NCKC
        June 22         TBD (probably San Fran, Newark, or the Presidio)
        July 27-28      Berkeley        Berkeley Kite Festival & 
                                        West Coast Kite Championships
        Aug 17          Sunnyvale
        Aug 31-Sep 1    San Francisco   Golden Gate Challenge (a NCKC event)
        Sep 7           Berkeley        --> BASKL Awards - no competition <--

All these date and locations should be confirmed in the next week or two.
I'll post a followup at that time.

BASKL is a no-frills competitve sport kite league.  Costs are kept down, so
entry fees are low ($10 per person last year, with family discounts).  The
idea is to provide regularly scheduled events in a local area.  For more
information, email [email-masked].

Darrin Skinner
President: Bay Area Sport Kite League

Skinner Consulting
1010 Aster Ave
Sunnyvale, CA 94086
voice (408) 733-5483 - fax (408) 733-4252
email [email-masked]

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