Date:	Wed, 2 Feb 1994 22:24:36 -1000
From:	vdhamer@prl.philips.nl
Message-Id: <9402030824.AA01622@ist1.prl.philips.nl>
Organization: Division of Applied Sciences, Harvard University
Subject: Sputnik hopping (designer's reply)

Regarding the "hopping" of a Sputnik (from Stunt Kites to make and fly)
as reported by Tom Jackson.

I received the following answer when I phoned the book's author, Nop Velthuizen:

* No, they really do fly well, but...
* Yes, some Sputniks have exhibited this or similar problems. In fact,
  Nop himself built a series for a 6-man team (Dike Hoppers) and 2 had
  problems which couldn't be traced to visible differences.
* Nop recommends the following solution: enlange the bridle strings wich are
  directly attached to the kite by a factor of 2. These are the lines between
  points a, b and c (for a Sputnik 2) and a..e (for a Sputnik 1). This appears
  to make the making/adjusting of the bridle less critical.
* Nop remarked that if you really wanted to do it right, you should
  keep the overal shape of the kite's curvature identical by shortening the long
  lines attached to points c (for a Sputnik 2) and e (for a Sputnik 1) to
  compensate for the above lengthening of the short lines.

I hope that I have been able to describe this clear enough (I'me just the
rec.kites-to-author gateway in this matter and don't own the English language
version of the book myself).

Peter van den Hamer

PS: Nop has describes this Sputnik problem in a forthcoming article in the
Dutch language magazine Vlieger. The article deals with the issue: "how come
it don't work when I build it just like it said". I may translate relevant
parts of the article when I get a copy (assuming there are still Sputnik
problems out there).



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