Rudder angle question

Discussion in 'Multihulls' started by Charly, Dec 23, 2013.

  1. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    What is the maximum useful angle of turn on a catamaran rudder? Where should the stop be set? And what about getting out of irons? More rudder for that? Any feedback appreciated.
     
  2. pogo
    Joined: Mar 2010
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    Location: Germany Northsea

    pogo ingenious dilletante

    90 Degrees
    The max. angle of attack is about 30- 40 degrees
    but , The max angle of attack is defined by a/the tangente of boat's turning circle.

    The boat's stern is drifting , direction outside the curve., so angles of 80degrees+ are possible and common ---one can see it on each tacking dinghy, keelboat, modern yachts a.s. o. ----especially on match racers.
    Limiting the angle to 40 degrees , or so , makes no sense, the turning circle would be enlarged massive--bad for sailing- and habour manouvers .

    pogo
     
  3. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

  4. pogo
    Joined: Mar 2010
    Posts: 342
    Likes: 9, Points: 18, Legacy Rep: 73
    Location: Germany Northsea

    pogo ingenious dilletante


  5. catsketcher
    Joined: Mar 2006
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    Location: Australia

    catsketcher Senior Member

    On my cats I usually max out at about 30-35 degrees. Your foils can only handle an AOA of around 5 degrees before they stall so you can't push them way over anyway. As you tack you can push the rudders harder as the stern starts sliding sideways keeping the angle of attack within the envelope the foil can handle.

    I would not worry about ensuring that you can have your rudder hard over as the rudder comes up. I am happy with the cassette wherbey my rudders can only come up when straight and it works fine so you should be fine with the cutout you already have.

    cheers

    Phil
     
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