I've Made a Model

Discussion in 'Boat Yard Basics' started by WhiteDog70810, Aug 8, 2009.

  1. WhiteDog70810

    WhiteDog70810 Mostly Harmless

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    At Brett's suggestion, I've made a model of my creation.  For those that are interested in the back story, this was my original idea.

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    It was okay, but I refined it a bit and made it 18 ft.

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    While I feel that design is probably a better all around boat, it would require a lot more money to build and set up, so I returned to my 16 ft plan and removed the stringers and raised sole.  For low power, they aren't necessary.  This is what I got.

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    I have now created a 1:4 scale model using 1/8" masonite. 

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    I like the modeling approach, but I really was glad I had the digital model to pull measurements from. I had hoped to create a table of offsets from the model, but despite my best efforts, I can't rely on the accuracy of my measurements when I scale the dimensions back up.  I have come to the conclusion that I will build a jig and "wrap" the sides on to the full size frames in order to get the points to scribe the curves for the sides.  I had hoped to cut everything flat and stitch the sides, sole and transom together and add the frames afterward.  Oh well.  Now I just have to get the ply. 

    Thank goodness the most accurate tool I had could only get to the closest 1/32".  If I had the capability to measure to 1/64", I would be really pissed because of my inability to be accurate because my pencil marks were too thick.  I can be kinda OCD.

    Nate
     
  2. jasonrl23

    jasonrl23 Plays with Glass...

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    Nice!

    Your first model reminds me of what a streamlined gheenoe might look like. It looks good. Defintely like the updated versions much better though.
     

  3. Brett

    Brett > PRO STAFF <

    I see a bit of swamp boat lines in that model.
    Looks kinda like an Atchafalaya crawfish pirogue.
    Stitch and tape construction won't give you the most accurate work,
    still, when you get to full scale construction you'll find yourself adjusting
    frames and bulkheads to make the lines look better as you work.
    Don't sweat the sixteenths, that's what block planes and sandpaper are for.
    Wood boats are supposed to have life in their lines, not be pixel perfect.
    Looking forward to seeing the final build, good work.
     
  4. firecat1981

    firecat1981 BBA Counselor

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    nate with a bottom as flat as that you realy don't need to build a jig. 2 of my original models were flat bottoms but I went with a small v up front for a smoother ride. I learned while making the model that the flat bottom would have simplified the process and would have cut my build time by 1/3rd. Bateau.com had a few good write-ups about the style you want to make. good luck. ;)
     
  5. JaredFacemyer

    JaredFacemyer Well-Known Member

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    Those are some awesome models, what program did you use?
     
  6. WhiteDog70810

    WhiteDog70810 Mostly Harmless

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    I used Google Sketchup to draw the digital model.  It is not nearly as complex as some of the CAD programs, but it also doesn't have the bells and whistles.  I played with the free Delfship but couldn't figure out how to get it to work well.  It was hard for me to draw good curves.  However, Delfship will break the model down and show you the dimensions of the parts in as you would cut them out of the ply.  Sketchup will not do that. 

    I really like having the digital model for reference.  However, it was much easier to build the 1:4 model than it was to learn how to draw it on the computer. Fortunately, I had plenty of time while deployed to figure it out.

    The masonite is easy to work with and I got some useful info from the 1:4 scale model.  I tried a 1:12 model out of cardboard, but I had trouble being accurate, but for figuring out basic shape, it would be a quicker approach.  There is no need to spend the time making a 1:4 model until you have the big picture firmly in your head.

    Regarding accuracy, I figure the more obsessive I am in my planning, the more minor my deviations will be when it comes time to build.  Trust me, I don't expect perfection nor do I really care about 1/16" screwups.  However, 1/2" screw ups will keep me awake at night.
    ;D
    Nate
     
  7. firecat1981

    firecat1981 BBA Counselor

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    trust me, at first the 1/2 inche screw ups bothered me but a little putty and shes all pretty again ;D

    The biggest problem I've run into is that the masonite, the same stuff I used for modeling, doesn't act at all like wood. When I designed and even modeled my boat it was planned that the 2 bulkheads and transom would be of equal size and shape so the only variation would be the bow. Well that didn't work out at all, when I stitched it all together is had a very wavey and unnatural shape and looked really bad, so I had to remove it all and rebuild everything to the natural shape and curve of the wood. I'm really glad I did it cause it looks sweet now and gave me alot more room to build decks, plus the new shape should be a dryer ride.
    I guess my point is unless your constructing a mold to lay FB in, which your not obviously, Don't count to much on finalized plans cause things will always change.
     
  8. WhiteDog70810

    WhiteDog70810 Mostly Harmless

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    Good point. I am trying to make it so all the curves are as gentle as possible and only make the wood to flex in one direction. The model has a slight twist in the sides toward the front half of the boat that will not be kosher with real ply. I expect there will be significant artistic license taken before it is said and done.

    Nate
     
  9. firecat1981

    firecat1981 BBA Counselor

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    well don't worry to much about it, the luan can bend in many ways and is easy to work with. did you look at that web site? if you use their process but just use temp bulkheads instead of making seats you can have this boat done in just a few weeks.
    I just flipped my hull a few hours ago and I can tell you that the stitch and glue meathod did produce a nice tight seam.
     
  10. B.Lee

    B.Lee Well-Known Member

    A 1/2" screw up is relative. It really depends where that screw up is located!

    There is not much that a sanding block, some thickened epoxy, and some glass cloth can't correct.

    I like the looks of your model, and I like that you simplified the design. I thought your original design was a bit over-built.

    Are you using luan, marine ply, or what?

    I flipped the Sawdust Skiff this weekend, and pretty soon will be done with Brett's construction base. I have been directed to pass it on to build another one, are you nearby? :-?
     
  11. WhiteDog70810

    WhiteDog70810 Mostly Harmless

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    I've cruised the Bateau site for years and have dug through their tutorials extensively. If they made a 16 ft D15 or a flat bottom FS18, I wouldn't be doing this myself. I am going to print out a few of the tutorials and may order the SC16 plans (very similar dimensions and bill of materials) before I get in to the thick of it so that I have some references.

    I plan on using Marine Ply and wrapping it around temp bulkheads. Thanks for the offer of the base. It would save me some time. However, I am up in NC, so I will have to figure it out on my own.

    Nate
     
  12. B.Lee

    B.Lee Well-Known Member

    Same reason I designed my own skiff. After mulling over various bateau designs, I wanted soemthing that was my own. FS18 was too long, too narrow. SC16 was close, but too unstable. FS14 & 17 are cool, but too much draft. I took some of each, threw in some of Brett's ideas, and managed to mold it all into the picture I had in my head.

    Once you have a model in your hands, it really fuels the build process forward. I'll be watching in the peanut gallery...
     
  13. firecat1981

    firecat1981 BBA Counselor

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    Contruction base? we don't need no stinkin construction base ;D :D :p...........Although it would help.

    I wouldn't bother ordering the plans cause all you will really get is sized cut outs that won't suit your build. just go at it, after a few days of work you will see the big picture. the design you made is nice and simple and you won't have any issues bending the ply to form it. I'd sooner work off your cad design, but I'd follow the bateau meathod.
    (ie stitch the bow, stitch the sides to the transom, install bulkheads to get form then scribe the bottom from there.....this is extremely simple and would have saved me 10 days if I did a flat bottom)
     
  14. WhiteDog70810

    WhiteDog70810 Mostly Harmless

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    With the SC16, the bill of materials is 4 sheets 1/4" ply and 2 sheets 1/2" ply. With that little 1/2" ply, I think they use 1/4" for the upper decks. If so, I want to see how they are bracing the decks that aren't supported by flotation foam. No one has a good build gallery on Bateau that shows using 1/4" ply for the decks. Since the dimensions and spans of my hull are very similar, I'd like to use 1/4" to save weight if possible.

    Nate
     
  15. Brett

    Brett > PRO STAFF <

    During the framing of the bow deck on the Slipper,
    I learned that adding a bend to the plywood adds rigidity.
    After completing the build, I realized I could have used 1/4 luan
    by simply adding a skin of 6 ounce glass to the underside of the deck
    as well as the skin on top. Between the two layers of glass
    and the curvature of the plywood, the flex inherent in the luan
    is almost eliminated. And as a side benefit, the decks become self draining.

    http://picasaweb.google.com/bdefalco/BuildingTheGrassSlipper#5225180380678094962

    http://picasaweb.google.com/bdefalco/BuildingTheGrassSlipper#5226652703471055874

    http://picasaweb.google.com/bdefalco/BuildingTheGrassSlipper#5230733367492553778


    As to framing spacing, 16 inches on center port to starboard.

    http://picasaweb.google.com/bdefalco/BuildingTheGrassSlipper#5227821824864453970
     
  16. firecat1981

    firecat1981 BBA Counselor

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    Nate if you look through the pictures on the sc16 you can see they used the 1/2" for the decks in a few of them. as far as bracing goes you would need very little because of how narrow the design is. Just some blocks on the sides and a bulkhead or 2 and it will be sturdy especially once its glassed.
    As far as floatation foam goes, I thought the same as you, that it can be used as a structural brace but I was told otherwise by several people in the know. Basically there are several different activators for expanding foam and the floatation one will get you nice lite foam, but it will be structurally weak and easily compressed if used under a deck as bracing. If you use a denser activator then you can do that, but it won't give you the floatation you will be looking for.

    your best bet right now is to go to customegheenoe.com and look at how the DIY guys made there own decks and floors. Just like here theres alot of great guys and good info. also since your great with CAD renderings and all heres a link to some old designs that a few have artist renderings and blueprints.
    http://www.svensons.com/boat/

    enjoy. :D
     
  17. WhiteDog70810

    WhiteDog70810 Mostly Harmless

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    Great with CAD? Now you're just buttering my up.
     
  18. firecat1981

    firecat1981 BBA Counselor

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    Well you figured out how to make a computer model where i had to go old school. Although the concept of a computer model really didn't occur to me till I saw yours. but it would have been a good tool to use especially since I had a bunch of people ask me where they could buy the plans for my boat :eek:
     
  19. Frank_Sebastian

    Frank_Sebastian Well-Known Member

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    Nate if you are ever around Sebastian I would like to take you for a ride in my D15. I have built a lot of boats during my lifetime. The D15 has something about it that I can't get enough of. It seems a perfect balance between all things that I like in a boat. When fishing general species like trout, sheephead, flounder and the like I run an 8 HP 2 stroke Tohatsu. When fishing bait and spots I change over to a 3.5 four stroke Tohatsu. I have 5 registered boats between 22' and 14'. The D15 gets the call 90% of the time anymore. I also have a GV 18 cut out and ready to assemble. (shrimper)

    Best regards,
    FRank_S
     
  20. firecat1981

    firecat1981 BBA Counselor

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    Frank the d15 was what I was gonna build before I decided to design my own. do you have pictures of the build process? and is it a flat hull?