Friday, June 17, 2016

Another Leeboard Idea

I have been seriously kicking around the ideas of hinges for the rudder and leeboards to be done with rope lashings.

Here is an idea for the leeboard attachment.  Basically the leeboard has a one inch bolt in it, that protrudes inboard to rest on a rail made up from steel pipe.  This can be welded up or made from galvanized pipe fittings.  Depending on the length of the rail the leeboard can be positioned anywhere, and then lashed in place.  The board can wing up, or raise aft in the shoals.  A rubber bumper on the board protects the hull.


12 comments:

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    1. I'm thinking around 100lbs a piece but I haven't made them yet or even decided on the exact materials...

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    2. If not secured to the boat I see a real opportunity to loose one over the side.

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  2. Al, Intriguing. I saw the word "lash" in your description, but I'm having difficulty imagining how that might work. If you're inclined to provide more details, that show how it can simultaneously be secure and flexible, I'd be eager to read / see that.

    Yoda

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  3. I was not able to draw the rope lashing with Sketch Up and left that to the imagination. But to describe it further, if you were to get a nail and cross it over another nail, then wrap string around the joint two ways, so it forms an X, then that is how the lashing would look. It allows either nail to rotate if you twist hard enough. I can't lose the board overboard because the head of the bolt won't pull through the lashing. However, the board can wing out on the other tack, or rotate aft if it hits and underwater obstacle. I would likely use 1/4 inch nylon rope to lash it - I would start with two half hitches around the rail then over the bolt, cross under the rail, back up over the bolt, repeat several times and then finish with two more half hitches around the rail.

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  4. did you see Dave's post on his travelling boards from a couple of years ago?
    http://triloboats.blogspot.ca/2012/02/travelling-offcenterboards.html

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    1. I have a crazy idea. If I may.
      If you have one problem you have a problem . If you have two problems you might be able to have them solve each other.
      You have a problem deciding on a proper mast for low bridges.
      You have a problem deciding on a leeboard.
      Combine the two.

      In an earlier post you described a 'quadrapod' mast made from smaller aluminium pipe.
      my idea is to USE that idea then run another pipe a few inches above the gunnel, top of the deck?> between the front and rear leg on each side.

      that pipe will have a 'collar' on it. a slightly large, short piece of pipe, so that it can slied from front to rear. attach a leeboard to that sliding pipe . run a line to the top of the mast, pull the leeboard up out of the water SIDEWAYS, when it's not in the lee.

      now you can use any of several different sail rigs short enough to get under the bridge as you mentioned earlier. ( I STILL like the crab claw.)

      But wait...it get's better. Put a HEAVY weight on the bottom of the leeboard,( a bunch of poured in lead) when it's not in the lee pull it up PARTWAY, not altogether vertical. Won't it act as a counterbalance to heeling. Turn the leeboard in to a 'hiking board."

      The longer the leeboard, the more counteraction.

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    2. I have abandoned the quadrapod idea. There was a fair amount of feedback from knowledgeable people to show the drawbacks of such a set up and one of them was how noisy it can be. As for the leeboards, they'll only have enough weight to sink them. The boat is quite beamy so it won't heel much in any case. But your idea would be worth considering in something a little more tippy!

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    4. thank you for the kind words.
      did you know that the guy who designed paradox, enigma and little cruiser put a singe dagger board is the NOSE of little cruiser?

      that got me to thinking about a swinging dagger board mated to a bowsprit..what an unholy matrimony.

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    5. Yes, Everitt, I am aware of those cool designs. The great thing about kicking around oddball ideas is that it gets you thinking. Sometimes really great inventions come as a result of lateral thinking and musing on something seemingly ridiculous. I read one time about an engineer trying to redesign a steel rolling mill to get thinner sheets. He could not come of with a way to rebuild the machine. He told his wife about it and she suggested rolling two sheets through at the same time. Problem solved, and no rebuild required! All it takes sometimes is a new perspective.

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