From: "Thomas L. Clarke" <pipeline.com!tclarke@imagelan.com>
Date: Sun, 4 Feb 1996 15:30:22 -0500
Message-Id: <199602042030.PAA28247@pipe12.nyc.pipeline.com>
To: baidarka@imagelan.com
Subject: Retractable "skeg" on bairdara
I have a Dyson 5.28... I did not install the rudder in the plans (the one
which drops about 1 inch below the keel)... 2 reasons I didn't install 1) I
wanted to find out whether is is needed or not and 2) I had/have my doubts
of its efficacy in any kind of waves... without stalling and thus creating
a lot of drag... So... I've been thinkin'....
What if we created a retractable skeg/rudder that had an aspect ratio that
would be high enough not to stall when providing a turning moment large
enough to counter the kayaks tendency to turn upwind... (I've found this
only a problem in a rear quartering wind)...
My thoughts on a design to do this: a blade that, for the sake of
arguement, was about 4 inches (fore and aft) and 15 inches long... a pivot
point near the top of the blade... a pin, about 6 inches long thru the
pivot point.
The blade is attached, by the pivot point, to a quarter of a circle, the
radius of which is the height of the transom. This 'quadrant' is attached
to the transom by a pair of nylon cloth hinges (just as the designed rudder
is attached)...
The blade is made of two pieces of aluminum, with the quadrant sandwiched
between (plus a couple of thousands of spacers to ensure the blade would
pivot...
Attach steering lines to the ends of the pivot...
Attach 'pull-down' line to the back of the blade, running under the pivot,
and a 'pull-up' line to the back of the blade, running over the pivot...
Probably have to play with placement of these to make them work... I'd make
the pull-up/down lines of stretchy light nylon line so that there would be
enough slack if ran aground...
Could also make the quadrant two pieces with the blade sandwiched between,
but that makes the blade only a single thickness and I'd be concerned of it
getting bent...
Thoughts?
TLC