From: reich@nosc.mil (Ronald S. Reich)
Subject: Re: 2ND TRY: whisker position on spin-off
Date: Thu, 1 Sep 1994 13:48:02 GMT

>From: pp@wsinti09.info.win.tue.nl (Peter Peters)
Peter Peters writes:
>Ok, I'll try once more....
>I'd like to add whiskers to my home-made spin-off....

Stuff Deleted

Instructions   for  locating  whiskers  on  a  home  made   delta 
controllable kite.

The optimum location for the whiskers is on the trailing edge  at 
the  natural  valley  of the sail.  The  natural  valley  can  be 
located by:

     1.   Hang the kite from the ceiling with the bridle side  up 
and the back of the sail "Parallel" to the floor.

     2.   Lay  an extra kite stick (spar) onto each side  of  the 
kite.   Allow them to roll to the natural low point.   This  will 
create  the  natural  valley of the sail and in  most  cases  the 
"center of pressure" of the sail will be very nearly on the  line 
of that valley.

     3.   Mark and install the attachment for the whisker at  the 
trailing edge where the valley exits the sail.

Theory to support this location.

     The force of the wind will be concentrated at the center  of 
pressure  of  the sail on each side of the kite.  The  wind  will 
create a valley as it pushes on the sail.  If the valley  created 
by  the whisker is different then the natural valley  created  by 
the  wind then there will be a constant battle between  the  wind 
and  the whisker to shape the sail.  This battle could cause  the 
kite  to  buffet as the wind loads and unloads the  sail  due  to 
turbulence and or position in the wind window.

                 Good Luck, Good Winds, Good Fun
                   
                   Still Learning and Sharing,

                            Ron Reich

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