Plans for Gerr Nester

Discussion in 'Wooden Boat Building and Restoration' started by seangoodwin, May 12, 2011.

  1. seangoodwin
    Joined: May 2011
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    seangoodwin New Member

    A complete novice, I'm seeking plans to build the Nester dingy I've read about in 'The Nature of Boats". I cannot locate them on-line; not even at Gerr Marine.
    I would appreciate any information or advice. Cheers.
     
  2. Lurvio
    Joined: Jul 2009
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    Lurvio Mad scientist

    The book contains the plans, table of offsets is on page 82. Just have to loft her.

    Lurvio

    edit: Oh, and welcome to the forum.
     
  3. seangoodwin
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    seangoodwin New Member

    Thanks Lurvio. I didn't have the confidence to go with the plans in the book 'cause the drawings are small and the instructions brief. I might just have to jump in the deep end
     
  4. Lurvio
    Joined: Jul 2009
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    Lurvio Mad scientist

    You don't really use the drawings, they are just something to compare your lofted drawings. Do a search for 'lofting' here on the forum or in google, You'll find plenty of info.

    Lurvio
     
  5. cthippo
    Joined: Sep 2010
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    cthippo Senior Member

    I found these somewhere on the web and they seem to be pretty informative...
     

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  6. seangoodwin
    Joined: May 2011
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    seangoodwin New Member

    Thank you Lurvio & cthippo. Confidence is rising. I feel like I'm in the right place. Cheers Sean
     

  7. cthippo
    Joined: Sep 2010
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    cthippo Senior Member

    Basically, a table of offsets is an excessively complicated way of defining a series of points in three dimensional space. Each station is a length dimension and then the half breadths are the width dimension and the heights are, well, heights. So far, so good.

    Basically, lofting is the process of drawing dots based on the Dimensions in the table and then connecting the dots. For example, here is the Table of offsets for the boat Boston is building in "The game is afoot" thread...

    [​IMG]

    Lets look at an example, say Station 4. The distances between stations should be in the plans somewhere, so that gives you one coordinate. That means the rest of the points are going to be on a flat plane, and so easier to draw. The dimensions in these plans are the traditional Feet -Inches - eighths of an inch format.

    So, to lay out station 4 we start from a zero point in the middle of the hull at the bottom. The zero point is an arbitrary baseline, the actual bottom of the hull might be above this baseline.

    The first point is the raised sheer, which is the top of the hull. Note that it appears on boat the heights and half breadths parts of the table. The Heights number is 5-2-4 or 5' 2 4/8" or 5' 2 1/2" above baseline. The half breadth is 3-7-1 or 3' 7 1/8" from the centerline. measure these out and mark a point.

    Do the same for the sheer (4-9-2 or 4' 9 1/4" Height and 3-5-3 or 3' 5 3/8" from center) and chine (2-7-4 or 2' 4 1/2" height and 2-10-1 or 2' 10 1/8" from center)

    The buttocks and Waterlines (abbreviated WL) work the same way, but one of the dimensions is fixed. For the buttocks the breadths are 9, 18, and 27" from centerline and the waterlines are 9, 18, and 27" above the loaded water line (LWL) which is given on the plans, but is not readable (though Boston said it was 2' 4", so we'll use that).

    So lets develop some of these points. The buttocks are given as 1-7-1, 1-11-1, and 2-3-1 and we know the distances from centerline are 9, 18, and 27 inches respectively. See how that works? On the waterlines it's a bit more complicated, so let's work through it. The first is the LWL which is given as 2-5-4 on the table and we know the height is 2' 4". Waterline 1 is given as 3-5-3 and we know that it's 9" above the LWL of 2' 4" so the height should be 3' 1". Personally, I prefer to feed all this data into Freeship which will immediately identify any errors and spit out a table of absolute offsets which I find easier to work from.

    Once you have all your points laid out in this way, you take a bendable stick and lay it out so that it touches all the points. The article recommends driving nails into the floor at the points so the stick has something to bend against. you then follow the curve of the stick with your pencil and viola, you have a full size template which you can use to build the hull on.

    The drawings are just there to give you a general idea of the finished shape so you know if your finished stations look right. I know this sounds complicated, but it's really not that bad, just repetitive.
     
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