Shafts thru the transom?

Discussion in 'Powerboats' started by Buck, Sep 17, 2003.

  1. tom kane
    Joined: Nov 2003
    Posts: 1,768
    Likes: 49, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Perhaps taking a look at Surface and Subsurface Drive all in one
    may add to the confusion.Tom Kane
     
  2. Buck
    Joined: Sep 2003
    Posts: 12
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Deltaville, VA

    Buck Junior Member

    Does such an animal exist?
     
  3. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    If it does, I for one would be very interested to see how it works....
    Surface drives - or more accurately, their props - rely on being able to cavitate. As soon as you submerge them completely, they are unable to do so and tend to overload the engines. So I can't see how you'd produce a drive capable of both modes of operation.
     
  4. CaptPPan
    Joined: Oct 2003
    Posts: 45
    Likes: 2, Points: 0, Legacy Rep: 41
    Location: Bellport,N.Y.

    CaptPPan Junior Member

    Looks like this
     

    Attached Files:

  5. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    That's a regular propeller. Are you saying it runs as a cavitating propeller?
     
  6. tom kane
    Joined: Nov 2003
    Posts: 1,768
    Likes: 49, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    I am watching with interest and reading about.
    The Patent Cooperation Treaty. Tom kane:)
     
  7. martiniboat
    Joined: Oct 2003
    Posts: 5
    Likes: 1, Points: 0, Legacy Rep: 26
    Location: Ont,Can.

    martiniboat Junior Member

    Tom, what's the PCT all about? Just curious.

    Brian Kamrath
     
  8. tom kane
    Joined: Nov 2003
    Posts: 1,768
    Likes: 49, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Hi Brian, If you want to apply for a patent in a large number of
    countries one method is to make an application under the Patent
    Cooperation Treaty.This can simplify the process of seeking a
    patent in countries which are party to the PCT.Under that system
    you can make a single international application to cover as many
    countries that interest you..and so on.cheaper, other advantages.
    Tom kane.
     
  9. martiniboat
    Joined: Oct 2003
    Posts: 5
    Likes: 1, Points: 0, Legacy Rep: 26
    Location: Ont,Can.

    martiniboat Junior Member

    Cool, thanks Tom!

    Brian
     
  10. CaptPPan
    Joined: Oct 2003
    Posts: 45
    Likes: 2, Points: 0, Legacy Rep: 41
    Location: Bellport,N.Y.

    CaptPPan Junior Member

    It's an Ellis made in Florida, I think they call it an elephant ear. Yes it runs as a ventalated propeler, half out of the water. When I win the lottery I'll buy a Rolla.
     

    Attached Files:

  11. tom kane
    Joined: Nov 2003
    Posts: 1,768
    Likes: 49, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Thank you captppan.I believe I understand what you are saying.
    Looks more practical than many more expensive drives.tom kane.
     
  12. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    captppann: do you have performance data? I think without comparisons we can't really tell if it is a good or just a cool looking setup.
     
  13. CaptPPan
    Joined: Oct 2003
    Posts: 45
    Likes: 2, Points: 0, Legacy Rep: 41
    Location: Bellport,N.Y.

    CaptPPan Junior Member

    Unfortuately mine is a one of a kind boat so there are no easy comparisons with different drive systems.(except for a few made that are powered by outboards)

    I'm also not proped correctly yet so the numbers I have are far from optimum. At 3000 rpm she'll do just over 30knots now depending on load. That's with a single 330hp crusader.
     
  14. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Looking at your picture, if the propeller runs ventilated, the rudder is clear out of the water. How do you steer?
     

  15. CaptPPan
    Joined: Oct 2003
    Posts: 45
    Likes: 2, Points: 0, Legacy Rep: 41
    Location: Bellport,N.Y.

    CaptPPan Junior Member

    I guess theres just enought in the water to steer. She handles fine at speed and wonderful at idle. Backing up is another story.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.