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Kayak and Canoe Design Bulletin Board
Re: Reading Plans
Posted By: Darrell Pearse In Response To: Reading Plans (Steve A.)
Date: Thursday, 2 March 2000, at 11:04 a.m.
> Hi, I am hoping to build a pair of cedar stip kayaks and have been reading
> Ted Moores book Kayak Craft. This book includes plans given as a series of
> coordinates for each station. Having studied the numbers I can make sense
> of everything and get a reasonable looking shape for the hull but when I
> try to draw the deck I run into a problem. The numbers given for the
> height of the sheer and the height of the profile on the deck don't make
> any sense at all unless I reverse them, applying the profile height at the
> sheer and the sheer height at the profile. Things then look pretty good
> (the buttock heights look okay as presented) except the sheer taken from
> the deck height table (using the profile number) falls 1/4" below the
> sheer taken from the hull height table. So I have two questions:> 1)Is there an explanation for the reversing of the sheer and profile
> numbers in the deck height tables?The sheer and the profile are reversed in the book.
> 2)Why don't the sheer heights - hull and deck - correspond? (It did occur
> to be that the difference might result form the thickness of the skin but
> if that were the reason I would expect the deck to register 1/4"
> above the hull, not 1/4" below)The numbers for the hull and deck sheer are not the actual sheer. Where the two lines meet is the actual sheer.
The following is the email I received from Bear Mountain:
1) If you plot the hull and deck sections you will notice that they cross each other at the sheerline. Where they cross is the sheerline for the mold stations. The line for the hull continues up to the finished sheer height and the line for the deck carries out to the final finished sheer width. I have attached a sketch that shows the lofting of station 8 as an example.
2) Both the deck and the hull have the same baseline. Unfortunately in the printing of Kayakcraft the labels 'sheer' and 'profile', for the deck offsets only, have been reversed. I presume that is what gave you some confusion.
email: info@bearmountainboats.com http://www.bearmountainboats.com
The web site under the FAQ has the offsets for the stems. ( about the third question down )If it is getting a difficult, the plans are fairly cheap.
> One last note: Since I don't know how to read these plans I established my
> reference lines by assuming the sheer of the hull to be a common point in
> the breadth and height tables for a given station and working backwards to
> get the reference lines. It appears the horizontal reference lies above
> the kayak as it sits in a natural, upright position. Is this usual?> Any comments about this book and the plans it contains would also be
> appreciated.> Thanks.
> SAnderson
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