Results 1 to 20 of 20

Thread: Small Lead sled 1/4 scale hull model

  1. #1
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Small Lead sled 1/4 scale hull model

    Hello,
    Here are a couple photos of my 1/4 scale model of a 16’ LWL & 27.5’ LOA, 2752, D/L 299.95, S/D 29.74, B/n 1.382,WS 122.95, 1300 lb. of leaded Full keeled, cine spoon transom, sloop rigged w/ warpable mast, or a small Lead Sled. Inspired by Herreshoff, Anker, and Cownishield . I am stand on the shoulders of giants. I made some Copenhagen Ship Curves a 1/3, 1/2, & full scale sets. All the curves on this boat are somewhere on one of them.
    My Construction Details Plans that are more inline with the 1800's methodology of construction, as my furniture has been. A third draft of Profile Drawings of Water Lines, Buttocks, and Diagonals sections are on my drafting table now. I have done a Saving to Investment Ratio on the cost of a 3D program, didn't pay off so I am using Excel. The 3D program would take the sport out of it for me anyway.
    Thanks to Eric Spomberg for his The Design Ratios A Naval Architect’s Dozen (or thereabouts) A primer on some basic principles of naval architecture for small craft. As first published on BoatDesign.net, January – March, 2010. By Eric W. Sponberg Naval Architect BSE, PE (CT) CEng (UK) https://www.ericwsponberg.com/wp-con...ign-ratios.pdf. His comment on the center of flotation and moving it forward as the boat heels over is one of the Herreshoff’s tricks has shed some light on the ever changing attributes of a sailboat for me.
    Will be add sails and lead to model this summer to see how it performs. If I can find a boat full of money somewhere I will start a full size boat. Building a model keeps me from losing my shirt but allows me to touch a dream. I am a custom design and build furniture company whom did his own designs for over 30 years and I detests fixing others mistakes.
    I have renovated some old fixer upper with papers already, here is one I kept. WISHING STAR https://www.woodenboat.com/register-wooden-boats/wishing-star-0
    If all else fails I will just go sailing. I guess that is the means to the ends anyway.
    John




  2. #2
    Join Date
    Jun 2000
    Location
    Pleasant Valley NS Canada
    Posts
    17,325

    Default Re: Small Lead sled 1/4 scale hull model

    Nicely done! I hope that it sails like a witch.
    Hope for the best, but plan for the worst.

  3. #3
    Join Date
    Sep 2003
    Location
    Brunswick, Maine
    Posts
    1,573

    Default Re: Small Lead sled 1/4 scale hull model

    Gorgeous!
    Will she be radio controlled?

  4. #4
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    mmd,
    The lead that I have started to shape is at 22.5 lb. I have a 1,300 lb. of lead that would be in the full size boat and I need 20.33 lb. for the 1/4 scale model. I still have some fitting and shaping to do. I plan on reducing the front of the foils width, moving the maximum width back to around to 40% to 45% from the leading edge. I have been reading a lot on this??? and am becoming more confused, I will sleep on it for a while and look for answers in other proven fast lead sleds.
    To make this a more accurate model I will need to reduce the deck framing weight and rebuild the keels dead wood out of White Oak. Like what I have in my displacement calculates.
    I have access to Osage Orange lumber but large timber sizes are harder to come by. It's trunk has a lot of folds and are short, most sawyer don't like to cut them, unlike the mature white, swamp, and burl oaks that I have growing out back.
    The water department put in a new 12" line through a grove of oaks on our property. The ones that they cut 1/2 the roots system off will only make it for 10 years or so, that is hard on a tree. I need to get them down and milled before the bugs and diseases a get to them, but that is young mans work and labor intensive. They would be great ribs for a full size boat because I get flitches that way or sisters boards. I have been looking at two particular white oak trees in that group for quite a while with a treacherous gleam in my eye. They were perfect before the trenching for the water line, 35 ft. to the first branch, straight as a arrows, their leaves are huge, trunk 32" and 36" in diameter 5 feet up from the ground. Sounds cruel I know but I would turn them in to the most marvel things I can. I knew the walnut trees in the picture below and put them in my office.




    Quote Originally Posted by mmd View Post
    Nicely done! I hope that it sails like a witch.
    Last edited by John Howland; 06-24-2019 at 10:41 AM.

  5. #5
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Rob,
    I don't think so. Mostly to check my calculations so she doesn't end up down in Davey Jone's locker. IMG_4152.jpg
    Quote Originally Posted by Rob Hazard View Post
    Gorgeous!
    Will she be radio controlled?

  6. #6
    Join Date
    Nov 2011
    Location
    Salt Spring Island, BC
    Posts
    6,249

    Default Re: Small Lead sled 1/4 scale hull model

    Gorgeous John.

    Are the deck beams simply radiused or are they a section out of an ellipse?

  7. #7
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Gib,
    Thanks,
    I made ellipses. I used my Copenhagen ship curves. I made three sets a 1/3, 1/2, and full scale.
    I just used the naturally curved grain in the lumber for the model, it was not that much of a curve in the deck beams, the full size boat has a 4" of rise in 3'5" Most of the longer beams are in the cockpit area. The ribs are laminated over molds some were heating over a stove to achieve very tight radiuses. I didn't get out the steam box, even for the bow stem. Just a pan of boiling water over the stove. But I have bent a lot of wood over the years. The ribs and stem were laminated with thin strips so steaming is not required in most cases.
    The displacement of the models real weights have come out really close to the calculation displacement of a full size boat. I used pine in place of Oak for framing and made framing and ribbing larger for the easy of fasteners. As for the dead wood in the keel it was calculation as white oak and I used cedar. That is 1.4 lb. in the model. That's quite a lot of weight when the model should weight 43.47 lb. and actual boat should weight 2782 lb. A large part of the boat weight is in the 1300 lb. keel or 20.33 lb of lead for the model.
    Thanks again for your kind word.
    John

    Quote Originally Posted by Gib Etheridge View Post
    Gorgeous John.

    Are the deck beams simply radiused or are they a section out of an ellipse?
    Last edited by John Howland; 06-24-2019 at 02:14 PM.

  8. #8
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Bib,
    It’s a descending curve steeper at the sheer line.
    I am new to sailboat design but look at nature for solutions to points of concern and it just looks better to copy natures solutions.
    Johns

  9. #9
    Join Date
    Jan 2004
    Location
    Norwich,United Kingdom
    Posts
    6,388

    Default Re: Small Lead sled 1/4 scale hull model

    Nice work.Will you be varnishing or painting the model?

  10. #10
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Working on sail design now. I like the Narragansett bay curved mast and long battens, one of the Herreshoff's design. I have a Star One Design Class with its warpable mast and owned a Prindle Escape 18' cat with fully battened main sail. I like both for thoughts attributes as well and am trying to combine a warpable mast with a long battened sail. It is over my head at this point and what the consequences of this would be and I haven't a clue of the durability of such a combination. So I will most likely go with one or the other. Graff rigging has most elegant lines but have some draw back. The most prudent thing would be to use an existing set of sails from a proven design of around 350 sf. Keeps cost down because I may need to buy a set of used sails.
    Poor folks have poor ways.
    John

  11. #11
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    John,
    I have some madrone burl veneer left over from a job that I hope to vacuum clamp that over the hull. I may try epoxy resin with my vacuum pump system, old paint pot, and bag materials.
    Most of my mode of operations (modus hoppperandi) on this project has to do with the next project. The Vacuum system is a deviation from my normal 1800's methodology of building but it has it merits.
    So the answer to your question is varnishing or transparent finish would be my chose. I hope to use $Honduras mahogany$ planking and trimmings on the full size boat. When I find that boat full of money.
    John

    Quote
    Nice work.Will you be varnishing or painting the model?

  12. #12
    Join Date
    Apr 2017
    Location
    Decatur, Georgia, USA
    Posts
    268

    Default Re: Small Lead sled 1/4 scale hull model

    John, you have caught my attention with your beautiful model, very interesting narrative, and that amazing piece of cabinetry. I look forward to seeing how all this develops!

    P.S. I caught the presence of what looks to be, from the speakers on the top shelf, a large and complex bit of hifi gear, which, along with the music it makes it possible for me to hear, has been a serious interest of mine since my teen years, back in the ‘60s. I hope that, if time allows, you might say something about your system and your taste in music.

    All the best.

  13. #13
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    45,294

    Default Re: Small Lead sled 1/4 scale hull model

    Quote Originally Posted by John Howland View Post
    Hello,
    Here are a couple photos of my 1/4 scale model of a 16’ LWL & 27.5’ LOA, 2752, D/L 299.95, S/D 29.74, B/n 1.382,WS 122.95, 1300 lb. of leaded Full keeled, cine spoon transom, sloop rigged w/ warpable mast, or a small Lead Sled. Inspired by Herreshoff, Anker, and Cownishield .
    If all else fails I will just go sailing. I guess that is the means to the ends anyway.
    John



    Quote Originally Posted by John Howland View Post
    mmd,
    The lead that I have started to shape is at 22.5 lb. I have a 1,300 lb. of lead that would be in the full size boat and I need 20.33 lb. for the 1/4 scale model.



    Beautiful workmanship, but. If you want a sailing pond yacht to stand up to its rig, you will have to increase stability by hanging the ballast a lot lower than to true scale.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  14. #14
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Chris,
    John Barleycorn would come to mind. As for the system I grew up in the 60's also and need 8 ohms just to hear the music. Just kidding, music is made to be heard at a certain volume like Mussorgsky Night on Bald Mountain.
    Thanks for your kind words,
    John
    Quote Originally Posted by Chris Noto View Post
    John, you have caught my attention with your beautiful model, very interesting narrative, and that amazing piece of cabinetry. I look forward to seeing how all this develops!

    P.S. I caught the presence of what looks to be, from the speakers on the top shelf, a large and complex bit of hifi gear, which, along with the music it makes it possible for me to hear, has been a serious interest of mine since my teen years, back in the ‘60s. I hope that, if time allows, you might say something about your system and your taste in music.

    All the best.
    Last edited by John Howland; 06-25-2019 at 02:55 PM.

  15. #15
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Peerie,
    Is that because a hull weight is converted down in a cubed number
    =SUM(2782lb./4^3) or 2782/64=43.47 lb.
    and the sail area is squared number
    =sum(350sf./4^2) or 350/16=21.8 sq. ft.
    I understand of a 1/4 scale model and the viscous sublayer between the hull and the turbulent boundary layer could have a large potential difference between the model and full scale boats. I suppose the sails has a similar effect.
    Down the rabbit hole we go.
    Thanks,
    John



    Quote Originally Posted by Peerie Maa View Post
    Beautiful workmanship, but. If you want a sailing pond yacht to stand up to its rig, you will have to increase stability by hanging the ballast a lot lower than to true scale.
    Last edited by John Howland; 06-25-2019 at 02:59 PM.

  16. #16
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    I am building a model so that if I get the chance to build a full size boat, I could avoid some of pit falls of a first time builder during the construction process and save some time and trees.
    I think I will just cut the dead wood just above the lead, add a couple of bars or some more dead wood between the two sections, that will extend the leaded lower section too what ever I need to keep it from being knock down. I can still take that extension section out if I wanted to make the model look like the boat.
    That should keep me out of the rabbit hole on the model for now.
    As for the full size boats the calculation are daunting, Alice.

    John

  17. #17
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    45,294

    Default Re: Small Lead sled 1/4 scale hull model

    Quote Originally Posted by John Howland View Post
    Peerie,
    Is that because a hull weight is converted down in a cubed number
    =SUM(2782lb./4^3) or 2782/64=43.47 lb.
    and the sail area is squared number
    =sum(350sf./4^2) or 350/16=21.8 sq. ft.
    I understand of a 1/4 scale model and the viscous sublayer between the hull and the turbulent boundary layer could have a large potential difference between the model and full scale boats. I suppose the sails has a similar effect.
    Down the rabbit hole we go.
    Thanks,
    John
    Close but no coconut.
    The heeling moment is the 1st moment of area (sail area x height)and so scaled as the cube, but form stability is the second moment of waterplane area, so scales as the 4th power, eg for your model it is 1/4 of what is needed. So to compensate you have to lower the CoG by hanging the lead on a deeper fin keel. Like this:


    Model makers building a scale model of an existing prototype like yours usually build the model as light as possible, and then add a removable bulb/fin keel. That way they can display the model without the keel, and add it for sailing.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  18. #18
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Peerie,
    There is that pesky forth dimensions of time or the movement in space time that I am not use to add to the equations.
    It will take me a while to totally understand what you have said, I understand all of the words in thous
    sentences but don't know what you really mean yet. It takes a while sometimes to let the information filter in.
    Thanks for sharing your knowledge.
    John
    Last edited by John Howland; 06-25-2019 at 08:07 PM.

  19. #19
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    45,294

    Default Re: Small Lead sled 1/4 scale hull model

    Quote Originally Posted by John Howland View Post
    Peerie,
    There is that pesky forth dimensions of time or the movement in space time that I am not use to add to the equations.
    It will take me a while to totally understand what you have said, I understand all of the words in thous
    sentences but don't know what you really mean yet. It takes a while sometimes to let the information filter in.
    Thanks for sharing your knowledge.
    John
    The heeling moment is easier to grasp. You know that it is easier to lift a weight close to your body than out at arms length. The length of your arm is the lever. Then with sails it is the area, width times height, that generates the force that gravity creates for your weight. So the lever arm x the length x the height of the rig is a cubic function, the third power.

    Stability is more complex, it is about how the volume of displacement moves with heel. It has been found that this is the inertia or second moment of area of the waterplane, the second moment is each element of area times its lever arm squared, or to the power of 4.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  20. #20
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Yes, Archimedes, Newton, Bernoulli's, Planck, Pascal, Borg, Einstein just to mention a few are all on board. Seemed kind of crowded so I through I would throw some of them over board in my attempt to understanding the scaling down a full size boat. In hindsight I should have left Newton on board.
    As the boat changes it's angle of attack
    Archimedes, Newton, and the rest seem to be changing their positions. Keeping track of them would seem be the trick for designing a boat with a diverse set of attributes.
    I have just started to understand who is on board and some things will take tens of thousands of hours to understand. Thanks for the leg up.
    John




    Quote Originally Posted by Peerie Maa View Post
    The heeling moment is easier to grasp. You know that it is easier to lift a weight close to your body than out at arms length. The length of your arm is the lever. Then with sails it is the area, width times height, that generates the force that gravity creates for your weight. So the lever arm x the length x the height of the rig is a cubic function, the third power.

    Stability is more complex, it is about how the volume of displacement moves with heel. It has been found that this is the inertia or second moment of area of the waterplane, the second moment is each element of area times its lever arm squared, or to the power of 4.
    Last edited by John Howland; 06-26-2019 at 02:39 PM.

  21. #21
    Join Date
    Sep 2018
    Location
    MO United State of America
    Posts
    41

    Default Re: Small Lead sled 1/4 scale hull model

    Thanks to Eric Spomberg for his The Design Ratios A Naval Architect’s Dozen (or thereabouts) A primer on some basic principles of naval architecture for small craft. As first published on BoatDesign.net, January – March, 2010. By Eric W. Sponberg Naval Architect BSE, PE (CT) CEng (UK) https://www.ericwsponberg.com/wp-con...ign-ratios.pdf. His comment on the center of flotation and moving it forward as the boat heels over is one of the Herreshoff’s tricks has shed some light on the ever changing attributes of a sailboat for me.
    Here is my drawing of a Herreshoff 15' One Design Class. I did a Table of Offset in Excel as well as construction Drawings of the Profile, Half Breadths, and Diagonals in 1/4 scale of it last winter before starting the Hummingbird’s planes. I wanted to make sure that these are two different boats.
    The full size sailboat carvings will be about a speech given by Diotima, it is a story repeated by Socrates in Plato's The Symposium. I have some ideas for the carving/archetypes that I will apply to the full size boat but they are not completely formed yet.


    The Solid Walnut Armoire built in Victorian revival style (photo below). A story in wood of the Arthurian myth as told by Gawain and others.

    The lower section is about Merlin’s encounter with Uther Pendragon and the building of a castle. Arthur father Askanar, two hidden dragon eggs under mountain were it was to be built. Excalibur is the sword that divides the doors and extends into the lower sections connection the two story of Arthur and Merlin. The upper section is about Arthur Camelot, as you look at each carving you can attribute them to Arthur story. The shields are for the Knights of the Round Table, columns are fore the Camelot, on the hilt of Excalibur is a lions head and a top of that is a clock for the round table, and the finials are the for the grail and the search of the purer of heart.
    I hope to combining the ontology aspect of the human experience to a sailboat epistemology forces.
    John


    Walnut enter.jpgIMG_2866.jpgIMG_E3995.jpgIMG_4152.jpg

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •