• MyCanoe700S

    agp.cooper • 05/29/2017 at 08:42 • 0 comments

    MyCanoe700S

    A design that is half way between a canoe and a kayak. The idea is to:

    • add some sheer the the design
    • add buoyancy tanks
    • reduce the sole width to limit slipping of the paddler sideways (and potential capsize)
    • increase secondary righting moment (stiffness)
    • reduce paddle interference
    • add a double thickness plywood for the sole (for concentrated loads)
    • Reduce the overall thickness of the plywood and therefore the canoe weight

    Here is the design:

    (Yes it is a balsa model)

    And another view:

    Here is the 3D design:

    And the 2D design (two sets need to be cutout):

    (Note: the plywood is 2500 mm x 1220 mm x 4 mm)

    Here are the key files:

    • MyCanoe700S_BoatOffsetTable.xlsm
    • MyCanoe700S.csv
    • MyCanoe700S_3D.dc
    • MyCanoe700S_3D.dxf
    • MyCanoe700S_2D.dc
    • MyCanoe700S_2D.dxf

    I have not export the 2D (cutout) data to excel for formatting.

    Regards AlanX





  • My Canoe

    agp.cooper • 05/29/2017 at 08:01 • 0 comments

    The Design Files for My Canoe

    These are the for My Canoe:

    • MyCanoe_BoatOffsetTable.xlsm
    • MyCanoe.csv
    • MyCanoe_3D.dc
    • MyCanoe_3D.dxf
    • MyCanoeAsBuilt.xlsm (includes lofting offset table)

    Here is My Canoe:

    Regards AlanX

  • Pontoon

    agp.cooper • 05/29/2017 at 07:33 • 0 comments

    Key Files for the Pontoon Design

    This design is covered in the Process log so just the key files here:

    • Pontoon_BoatOffsetTable.xlsm
    • Pontoon.csv
    • Pontoon_3d.dc
    • Pontoon_3d.dxf
    • Pontoon_Layout.dc
    • Pontoon_Layout.dxf
    • Pontoon_Layout.csv
    • Pontoon_Layout.xlsx

    The pontoon (i.e. the outrigger):


    Regards AlanX





  • The Process

    agp.cooper • 05/27/2017 at 01:37 • 0 comments

    Background

    If you are interested in boat building, especially using “stitch and glue” plywood construction, then Carlson Design Hull Designer (http://carlsondesign.com/projects/hull-designer/) may be of interest to you. You will need to run this program in XP compatibility mode otherwise some of the options will not work.

    The main objective of these hull design programs is to create a 3D hull and then to “develop” or “unfold” the frames/bulkheads and planks/cut-outs for construction. Below is an example of a “stitch and glue" pontoon for my outrigger canoe.

    The 3D design:

    The unfolded (cutout) design:

    The cutout offset table:

    The lofted design:

    The cutout panels:

    The wired up (stitched) panels:

    The glued (epoxy filleted) seams:

    Top glued on, ready for sanding and Dynel (rather than fiberglass) tape:

    Coated with epoxy and trial fitted to the canoe:

    Done, fitted and painted):

    How did I do it?

    The following describes the process and the two key programs I use.

    BoatOffsetTable.xlsm

    The Excel file and macro allow you to enter the offset table and then to export the design to a CSV file for DeltaCad. Blow is an example of an offset table for a kayak:

    (source: https://hubpages.com/sports/Building-a-Cedar-Strip-Kayak-The-Basics)


    BoatOffsetTable.bas

    The DeltaCad macro imports the CSV, draws the design and unfolds (develops) the hull.

    Note: DeltaCad can be purchased for US$40 from https://www.deltacad.com.

    Workflow

    DeltaCad does not have a suitable table entry process which is why Excel is used. Below is the Excel offset table for the “Mini-Kayak”.

    “Mini-Kayak” is an adaptation of work by Bruce C. Anderson (http://buckwheat-anderson.com/bcanderson/Boatz/OSKayak/OSKbuild.html).

    The actual design is too small to be of practical use as a Kayak (refer to Anderson’s webpage).

    The above offset table has three additional features over an offset table:

    1. Chines have a colour for easy identification.
    2. Chines can be invisible (and ignored) if the colour is “0”.
    3. Chines can have a “break” or a sharp bend.

    Notes:

    • The design is in millimetres.
    • The stations are rounded to the nearest millimetre.
    • Any duplicate stations are deleted.
    • Stations within 5 mm of each other will have “breaks” automatically added.
    • Colour 0 is not processed.
    • If an interpolated value appears wrong or wildly off then you will need to add “breaks” to the chine stations near the problem area.
    • No curvature checks are made, the design may not be developable (i.e. the plywood may break).

    The offset table is exported to DeltaCad as a CSV file. The name of the CSV file is the same as the Excel WorkSheet name. To execute the macro just click the blue “Make CSV” arrow as shown above.

    In DeltaCad the macro (“BoatOffsetTable.bas”) is run to import the CSV file and draw the design. For complex designs, the actual process is iterative (i.e. chine by chine). Below is the imported and unfolded “Mini-Kayak” showing the main drawing components.

    Note: The unfolded panels are the cut-outs for the design and only one side is shown.

    Macro Options

    When you run the DeltaCad macro, it first presents a file manager window. It starts in the DeltaCad macro directory. You will need to navigate to your working directory (i.e. where the Excel file is located) and select and okay the CSV file. For the “Mini-Kayak” it is called “Mini-Kayak.CSV”, as shown below.

    The macro then presents the “Hull Sections” options box. Set the number of frames to 7 and zero the remaining entries as shown below. This option adds additional frames to the hull model.


    You should see the following design.

    Other Options

    If the “Frames” entry is set to zero then the offset table as entered in Excel will be drawn as below.

    The other option entries, create different sections (cross, long and plan) through the model. For example the...

    Read more »