16-18' "Sit-in" Planing Monohull ("Trapwing")

Discussion in 'Sailboats' started by Doug Lord, Feb 27, 2009.

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  1. Doug Lord

    Doug Lord Guest

    Trapwing

    The system on the trapwing will be capable of moving the crew between 3' and 4' in one second-faster than any "human" crew. And do multiple quick moves at that speed over a long period.
     
    Last edited by a moderator: Mar 12, 2009
  2. mark_m
    Joined: Apr 2006
    Posts: 9
    Likes: 1, Points: 0, Legacy Rep: 27
    Location: Uk

    mark_m Junior Member

    moving the crew between 3' and 4' in one second-faster than any "human" crew


    It takes less than a second to get out on a trapaze, which is a move of about 4' so I don't see how that is true.

    Let's assume that a blind, deaf crew with very fast reactions can adequalty balance a boat, then this implies that ~500w is an adequate motor size to power your robocrew. I didn't notice how sensitive the power requirement is to crew movement time. It looks like a 2second transit of 9 feet only requires ~500w output.
    I accept that my initial assumptions may have been overly pessimistic and that a much smaller motor and hence battery may be feasible.

    However, I think your (Doug and Rick's) estimates of the crew moving once every few minutes are very optimistic. They may be true sailing in very steady strongish wind on the sea with big courses. On my local lake you can't sail for three minutes without hitting a bank!
    check out this video of somebody sailing a musto skiff in marginal conditions: http://www.youtube.com/watch?v=xIWIoUcgWhU
    Those conditions would count as steady where I normally sail. He is continually moving in and out when going up wind.
    I initially assumed a 3% usage rate but I now believe 5% may be better for your calculations. If I was designing the boat I would assume 100% usage because of my local conditions and for a factor of safety.

    I agree with Bill though, these challenges are what interests me but they are still minor compared to the system design and integration issues.

    I'm confused as to why you didn't put your own numbers into the model to see for your self.

    I thought you might find this interesting:

    http://www.youtube.com/watch?v=jrn9V_SNB5A&feature=related

    (a Musto Skiff, with an electronic crew and no keel lead)
     
  3. Doug Lord

    Doug Lord Guest

    Actually, Mark, the requirements can be widely varied and still have more than enough power for a days sailing with a small battery. Speed is excellent and also proportional so no matter what the conditions are the skipper will be able to move the ballast the way it needs to be moved for top performance.
    I appreciate your effort in looking into this concept. Now, that you may have a different perspective on what is possible do you have any interest in looking further into it?
    That MustoRC is great-thanks! I bought one of his early boats. Did you see the MelgesRC above? Also did a microMoth, catamaran,tri and scow using the "Trapeze Power Ballast System". Worked well(the Moth was problematic) and was a blast to use-really adds to RC sailing. Too bad most rc sailing class rules prohibit movable ballast.
    I think the trapwing concept has a lot of potential and am adding it to the boat I'm building now. It was always in the cards that this would be one of the experiments done with my new boat which will be "convertable" between a straight foiler and this boat-it is an experimental platform. I already have two experimental rigs,two sets of foils and all the small pricey rigging parts. The mods to the hull are my focus now as well as finalizing the wing design. The hull is very narrow and not ideal for a "forgiving" application of the trapwing but will explore the wild side of the concept(no initial stability)-starting with 100sq.ft. of sail and 80 pounds of ballast and working up to 160lbs. and 160+ sq.ft.. with a 12'+ wing.
     

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  4. Steve Clark
    Joined: Jul 2004
    Posts: 221
    Likes: 28, Points: 28, Legacy Rep: 163
    Location: Narragansett Bay RI

    Steve Clark Charged Particle

    What I don't understand.

    I guess I just don't understand what advantage this boat has over a small trimaran of equal beam.
    The Challenger being one example.
    As near as I can tell, the trimaran will have superior performance with less complication.
    SHC
     
  5. Paul B

    Paul B Previous Member


    Simple:

    Gadgets!

    Not to mention FAME for the great designer of this "technology" (circle R, patent pending).
     
  6. Doug Lord

    Doug Lord Guest

    I'm not at all sure of that,Steve-particularly for the self-righting version. It has more SA than a WETA-and the power to carry it.
    challenger tri: http://myweb.tiscali.co.uk/sailchallengers/
    --------------------------
    Challenger
    LOA 14.76
    SA approx. 80sq.ft.
    Weight-308lb.
    ======================
    Weta
    LOA 14'
    SA 123.9 sq.ft +spin
    weight-220lb( some have said the Weta is 240 all up)
    =====================
    Trapwing
    LOA-16-18+
    SA 160sq.ft. +spin
    Weight-271-320lb.
     
    Last edited by a moderator: Mar 12, 2009
  7. Chris Ostlind

    Chris Ostlind Previous Member

    The sail area for the Weta is incorrect, as is the all-up weight.

    If you want to sell something, then have the decency to represent the competition accurately.
     
  8. Doug Lord

    Doug Lord Guest

    ===================================
    You,sir, are dead wrong-AGAIN!!!(ABOUT THE WEIGHT) But you're right about SA=123sq'-
    http://www.sailweta.com/specifications.html
    --------------------------------
     
    Last edited by a moderator: Mar 12, 2009
  9. Chris Ostlind

    Chris Ostlind Previous Member

    Actually, no Doug, I'm not.

    http://wetatrimarans.com/Weta_Specs.htm

    The Weta has a MAIN of 89 sq. ft. and a JIB of 34 sq. ft.

    The weight, Rigged Total is 220 lbs.

    The is the East Coast US distributor of the boat. Just a few miles up the coast from you. You should get to know them.

    Say you are sorry now and go back to the fuzzy room.
     
  10. Paul B

    Paul B Previous Member

    Dead wrong, but right!

    Now that is talent.
     
  11. Chris Ostlind

    Chris Ostlind Previous Member

    You had incorrect figures to begin your so-called power point and you got nailed for spewing the fake to make your claptrap wingy look good.

    Does it occur to you at all, that we can all see you there, scurrying around with the fever.

    Now, say you are sorry. We are all waiting for you to man-up.
     
  12. Doug Lord

    Doug Lord Guest

    Interesting comparison. The Trapwing is a bit heavier but much more powerfull. Would be an interesting race with the edge to the monohull,I think.

    Weta
    LOA 14'
    SA 123.9 sq.ft +spin
    weight-220lb(some have said the weta is 240 all up)
    =====================
    Trapwing
    LOA-16-18+
    SA 160sq.ft. +spin
    Weight-271-320lb.
     
  13. sigurd
    Joined: Jun 2004
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    Location: norway

    sigurd Pompuous Pangolin

    you can do self righting with small tris too
     
  14. Paul B

    Paul B Previous Member


    I wonder how this could be accomplished?

    Something that actually exists racing against something that isn't even up to the being called vapourware?

    A real boat racing against a collection of numbers typed onto a screen?
     

  15. Cheesy
    Joined: Aug 2008
    Posts: 315
    Likes: 12, Points: 0, Legacy Rep: 189
    Location: NZ

    Cheesy Senior Member

    As you already have some power consumption figures what actuator and control system are you going to be using? off the shelf?
     
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