Levi Drives Experimental (DIY)

Discussion in 'Surface Drives' started by xrudi, Aug 3, 2013.

  1. daiquiri
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    daiquiri Engineering and Design

    That is what any surface drive does every day- a blade in the water, the other in the air, full speed. Without breaking. If there were vibration and fatigue problems, then they were a structural issue related to that specific design - not to Levi drives in general.
    Cheers
     
  2. xrudi
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    xrudi Rudi Scholz

    I have never heard about this case. Maybe you know more about this. I would think that our inverted U shaped rudder would prevent blades from flying through the air. It certainly prevents personnel accidents when people fall over board. To me, an unprotected surface propeller has a great resemblance with an gigantic meat grinder mounted on the back of the boat.
     
  3. Agrodyne labs
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    Agrodyne labs Junior Member

    Here's my "levi" .....

    And I thought it was just a surface DR with 2 rudders?

    Boats since Noah....they all are propelled, they all steer... why all the fuss?
     

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  4. tom kane
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    tom kane Senior Member

    A Retractable shaft drive with out any rudders to save drag is a better proposition and give a choice of operating depth,in effect propeller diameter adjustment especially in fast following seas. A very simple adaption.
    .
    Rudders are not a good way to steer a boat and surface drives need a deep rudders to have any useful purpose (prevents prop walk) so also cancel out very shallow water boating.
    Just some of the advantages of Pivotal Drive for power boats.
     
  5. powerabout
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    powerabout Senior Member

    once you see a boat with a surface drive and its a windy day at the marina you realise why the biggest market is stern drives and they go just as fast for the average consumer
     
  6. Agrodyne labs
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    Agrodyne labs Junior Member

    Re: Surface drives...

    Great points....I built mine for a specific requirement. Had major prop walk issues until I added the 2 aluminum channels seen under the transom pad. works very well to control it. Also a surface drive at rest or slow speed tends to have the rudder or rudders deeper in the water. At planing speed in surface mode the rudders are not as deep , if well designed , keeping the steering effective without being touchy. I like all boats for different reasons. No two drives are equal in varied conditions.
     
  7. tom kane
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    tom kane Senior Member

    levi drives Experimental

    Stern drives have the propeller where it is most effective most of the time, and you can do the same with a retractable shaft drive, or use in Surface Piercing mode especially to run in shallows or over sand bars or maneuver in a Marina. Stern drives still have the weight in the wrong place for a good angle plaining craft.
     
  8. Agrodyne labs
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    Agrodyne labs Junior Member

    I fully agree....Stern DR for average, Surface for special race boats.....a prop anywhere for fishermen.
     
  9. Agrodyne labs
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    Agrodyne labs Junior Member

    BTW...that's 30 mph in 3 ft swells............on 8 hp. Surface baby....
     
  10. Agrodyne labs
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    Agrodyne labs Junior Member

    Tom Kane....Build a bathtub! NZ Boys are killin it.
     
  11. tom kane
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    tom kane Senior Member

    levi drives Experimental

    I love bath tubs it is a good design with plenty of room for family fun and plenty of buoyancy and stability for a given length and beam.
     
  12. Agrodyne labs
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    Agrodyne labs Junior Member

    did you know air NZ fly's the winner of the NZ bathtub circuit to Nanaimo BC for the world championships?
     
  13. tom kane
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    tom kane Senior Member

    For free I hope.My bath tub does not comply with the Rules.
     

  14. Agrodyne labs
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    Agrodyne labs Junior Member

    Got a bit off topic with the race stuff, last race post....Contact John Booker in Whitianga NZ, Owner of Pacific coast marine and diesel. He is an avid tubber, and has done much to maintain the sport in NZ. They have some very interesting ideas!
     
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