Most Efficient Boat Propulsion

Discussion in 'Sterndrives' started by tom kane, Dec 4, 2014.

  1. tom kane
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    tom kane Senior Member

    You don`t need to use high spec materials for a fun experimental drive, high strength steel for propeller shaft even in salt water and other cheaper materials and you can hot dip galvanize some parts. A quick wash with fresh water when washing your boat.
    Use composite water lube brgs in the torque tube ( only two needed) not any rubber types.I used Novasteen and they never did wear out enough to have to be replaced in any of my drives.

    A steerable Pivotal Drive for cats of any size should have no real problems to set up.
    As the shaft water seals would be above the water line (in most installations) the old boggy of leaking glands is a thing of the past and the rotation of the propeller shaft lifts water to cool the seal and glands although I did use ( stuffing box water glands) with water cooled channels just to try and never had heating problems. I only had some problems with motors and never any problems with the drives.
     
  2. myark
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    myark Senior Member

  3. tom kane
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    tom kane Senior Member

    TV1 New Zealand made a documentary film about the Pivotal Drive and also about the Safe Remote Fuel System for power boats (google).
    But unfortunately they "lost" the footage and I have never been able to get a copy.

    I would like one of these for Christmas as I am sure outdoorplay would do too.
     

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    Last edited: Dec 18, 2014
  4. tom kane
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    tom kane Senior Member

    Images show an experiment using an electric driven propeller (when needed) in place of, and working like a rudder, to turn the boat and maneuver at docking with a Pivotal Drive retractable shaft drive S/P.

    The gear was fitted to a separate transom so the original boat was nor changed.
    .
     

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  5. Agrodyne labs
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    Agrodyne labs Junior Member

    Tom...just wanted to say our bathtub boat project was originally designed with a trimmable drive...Pivotal you would say..Mostly to adapt to changing conditions.

    When we create that piece of the puzzle i'll let you know.
     
  6. tom kane
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    tom kane Senior Member

    Surprise me Agrodyne labs. I look forward in anticipation.
     
  7. Agrodyne labs
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    Agrodyne labs Junior Member

    You won't have to wait very long...almost there.
     
  8. Canveysteve
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    Location: Canvey island essex

    Canveysteve Junior Member

    What make n model is this if poss
     
  9. tom kane
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    tom kane Senior Member

    Hi Canveystyeve, That propulsion was called a "Viking" available in New Zealand some time ago but for unknown reasons (probably financial) did not continue in production.
    I may have other info which I will post if I can find it.

    I had a tractor drive in one of my early dingy boats and had a lot of fun with it in shallow water fishing and an outboard as main propulsion.
    I always liked a spare motor so I did not have to row home if damaged a prop.
     
  10. Canveysteve
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    Canveysteve Junior Member

    Think i have 1 ! Been trying to fing out for past 3 years what it is
    Did it have a cable to steere the lower prop section as mine does
     
  11. Canveysteve
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    Location: Canvey island essex

    Canveysteve Junior Member

  12. tom kane
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    tom kane Senior Member

    I have not seen that drive before and it is similar to the ones I posted except that it is not a tractor (pulls instead of pushing) drive but it is steered by swiveling the lower half of the drive with cables.

    I would love to know more about it. Let me know what you find.

    Perhaps if you search old Sea Spray magazines online there will be information
    about that drive.
     

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  13. Canveysteve
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    Canveysteve Junior Member

    Will do annd gbanks for your help !!! Has helped alot !
     
  14. tom kane
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Surely the most efficient propulsion system must be the one with the least metal in the water to steer and propel the boat efficiently and the one with the least number of driven parts to do that.

    And preferably the drive needs to be easily retractable for launching and retrieving and safe from damage in shallows from rocks and sand bars and many other advantages that an experienced boat operator should easily be able to work out for then selves.

    From oars and paddles to top sophisticated drives easy retraction and de-mounting is a must have.
     

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  15. OCB
    Joined: Dec 2015
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    OCB Junior Member

    Drive with least metal in the water.

    Surface drive must have least drag and moving parts. Maybe a link bar to keep the prop vertical will improve reverse. Below are drawings of my design.

    OCB

    Surface drive for most efficient.

    [​IMG]

    Subsurface for reverse flow under hull.


    [​IMG]

    Storage/Service

    [​IMG]
     
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