Outboard sail drive

Discussion in 'Propulsion' started by Forecaddie, May 11, 2023.

  1. Forecaddie
    Joined: Apr 2023
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    Location: Brisbane Australia

    Forecaddie Junior Member

    I am going to take a 4hp outboard and make it a through hull fixed saildrive. What would be the place for the rudder? Can I have it 2 feet aft?
     
  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    On what type of sailboat are you going to install this through hull 'fixed' saildrive?

    Are you planning on having a watertight seal around the leg, or will there just be a rubber gasket, in similar fashion to a conventional' saildrive leg?

    If the former, this might be difficult to achieve; if the latter, then you might as well just have an outboard well in the hull (in the cockpit area), and have the 4 hp engine easily removable.
     
  3. Forecaddie
    Joined: Apr 2023
    Posts: 48
    Likes: 6, Points: 8
    Location: Brisbane Australia

    Forecaddie Junior Member

    Water tight seal. Conventional but removing the leg and shortening the drive shaft. It will be for a 24’ power tri. I think I will have short 4” skeg with rudder. The hull I am using is a pointed catamran hull. The have adjustable outriggers to bring them close to the hull then wide when I transport things or go island hopping and camping. 4hp so I don’t have to register the boat.
     
    BlueBell and bajansailor like this.
  4. HJS
    Joined: Nov 2008
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    Location: 59 45 51 N 019 02 15 E

    HJS Member

    If you do not want to build a boat with an efficient stern, it is better to place the engine aft and provide it with a foil. In this way, you can adjust the engine position and tilt to achieve the highest efficiency.
    This of course assumes that the position of the overall center of gravity is optimized.
    JS
     
    Last edited: May 13, 2023
  5. Forecaddie
    Joined: Apr 2023
    Posts: 48
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    Location: Brisbane Australia

    Forecaddie Junior Member

    Thank you. Can you explain “efficient stern”?
    Rowing sculling hulls have pointed sterns. Good Idea for easy adjustability.
     
  6. HJS
    Joined: Nov 2008
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    Location: 59 45 51 N 019 02 15 E

    HJS Member

    Attached Files:

  7. Forecaddie
    Joined: Apr 2023
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    Location: Brisbane Australia

    Forecaddie Junior Member

    Thanks mate. I read the forum you mentioned and previous responses mentioned a hydrofoil on the stern of the main trimaran hull.I have looked at the Hysucat stern foils and may explore doing something like that. Thanks
     
  8. SolGato
    Joined: May 2019
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    Location: Kauai

    SolGato Senior Member

    You could also consider using X2 fixed motors spaced apart and use independent forward and reverse thrust for steering which would eliminate the need for a rudder.
     

  9. Forecaddie
    Joined: Apr 2023
    Posts: 48
    Likes: 6, Points: 8
    Location: Brisbane Australia

    Forecaddie Junior Member

    Thank you, I will look at the manufacturer-
     
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