Kick-up Rudder

Discussion in 'Sailboats' started by Lew Morris, Sep 21, 2002.

  1. Lew Morris
    Joined: Jun 2001
    Posts: 124
    Likes: 4, Points: 18, Legacy Rep: 92
    Location: Pismo Beach, Ca

    Lew Morris Industrial Designer

    Port San Luis, California is a great place to sail, but launch facilities leave a lot to be desired ... like sufficient depth of water at the launch basin during negative tides.

    My keel swings up, but my rudder doesn't. So I'm looking for a clever kick-up detail for a rudder.

    Ideally the "upper" portion (above waterline) would remain fixed in it's gudgeons and would be hung while the boat is still on the trailer. We have a pretty good surge into the basin some mornings and hoisting the rudder over the transom while trying to fit it onto the gudgeons ain't no fun... been there, don't like it... at all.

    I've seen one very simple design that sandwiches the upper and lower portion between to 1/4" thick aluminum plates. It works, but it is UGLY. But it works...

    O'day (I believe) uses/used a frame assembly that the rudder blade dropped into. Nice design, but rather heavy for a 22 footer that is already fighting a stern heavy condition (outboard, motor mount, and rudder... and me).

    Any thoughts, references, and/or sketches would be appreciated.

    Thanks, Lew
     
  2. tspeer
    Joined: Feb 2002
    Posts: 2,319
    Likes: 303, Points: 83, Legacy Rep: 1673
    Location: Port Gamble, Washington, USA

    tspeer Senior Member

    Chris White's book, "The Cruising Multihull" has a number of kick-up rudders illustrated. The typical types are:

    - pivoting blade with slot in head (ala Sunfish, etc)
    - rudder post & bearings installed in a cassette that pivots in a slot in the transom or sugar-scoop
    - inboard rudder installed in section of the hull that pivots up
    - vertical daggerboard sliding in a case that's pivoted on ordinary gougeons (doesn't kick up, but can be adjusted for depth)

    For your application, I think one possibility would be to make up a T-shaped bar. The cross of the T would be a tube with a rod running through it to allow the T to pivot about it. The pintles would be mounted to the vertical part of the T, and at the lower end of the T would be a short stud that slips into a sealed hole in the transom to help take the side loads. A line would hold the T-bar to the hull.

    One way to implement the line would be to go from the T through the transom to a cleat or a block and up to a cleat, etc. Another way would be to start at a cam cleat mounted at a shallow angle on the transom, go down to a block on the transom next to the bar, over the T-bar to another block, and up to a cam cleat. When the rudder grounds, it pulls the line out of the cam cleat, allowing the rudder to kick up. The chief problem with this method is that whenthe line goes from the blocks to the bar, it needs to be as close to fore-aft as possible. Just taking it in a transverse direction over the bar will not restrain it very well. My F-24 has its rudder hold-down rigged this way and it works well, although the rudder is of the pivoting cassette variety.

    You could drop a toping lift from the pushpit to hold it up when moored.

    The daggerboard option would also fit the bill. It would require a new rudder, but use the existing pintles.
     
  3. Lew Morris
    Joined: Jun 2001
    Posts: 124
    Likes: 4, Points: 18, Legacy Rep: 92
    Location: Pismo Beach, Ca

    Lew Morris Industrial Designer

    Seems to be a subject of scare interest.

    Thanks for your input Tom.

    Lew
     
  4. Guest

    Guest Guest

    Lew,

    Check out the kick-up rudder on the Com-Pac 16. This unit is used on most of the Com-Pac boats and it works great.
     

  5. Lew Morris
    Joined: Jun 2001
    Posts: 124
    Likes: 4, Points: 18, Legacy Rep: 92
    Location: Pismo Beach, Ca

    Lew Morris Industrial Designer

    thanks not yet registered guesty,

    i checked out the hutchinson com-pac 16 website but all i could decipher from the copy is that it is a cast aluminum affair with a stainless blade. no photos... at least no close-up ones.

    i then spent a little time searching around the net but could not locate any other source of photographic details of this assembly.

    got links...?
     
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