Loading ...
Sorry, an error occurred while loading the content.

Re: Micro rudder

Expand Messages
  • dir_cobb
    Dear all As I read this thread about fighting the tiller I was taken back to the plans of my Oldshoe which include: Tiller batten... bored to take movable
    Message 1 of 32 , Nov 11, 2010
    • 0 Attachment
      Dear all

      As I read this thread about fighting the tiller I was taken back to the plans of my Oldshoe which include:

      "Tiller batten... bored to take movable pins to hold rudder at various angles..."

      I had often asked myself why this was designed into the plans for the mizzen rigged boat (self steering and all that). I believe I now have the answer. PCB appears to have thought of tired arms going downwind and running and designed the solution into the boat.

      Does Micro also have one in the plans? I couldn't see the point of it so never fitted it in Oldshoe. Now I do and shall... All credit to PCB.(Doesn't stop your needing a strong rudder though).

      Just my two cents.

      David
    • Kathy Kreamer
      End plates help a low aspect ratio rudder, if it s shoal water you re after, but a high aspect ratio reduces drag the most. The high aspect ratio rudder can
      Message 32 of 32 , Nov 14, 2010
      • 0 Attachment
        End plates help a low aspect ratio rudder, if it's shoal water you're after, but a high aspect ratio reduces drag the most.  The high aspect ratio rudder can be smaller and you will get some reduced helm effort.  For more greatly reducing helm effort, the "balanced" aspect of a rudder is more important.  You can mix and match - a low aspect rudder can be balanced to get low helm effort.  You're arms are happy, but the rudder is draggy and the boat is not moving as it could.  - Bill


        From: bolger@yahoogroups.com [mailto:bolger@yahoogroups.com] On Behalf Of etap28
        Sent: Sunday, November 14, 2010 10:34 AM
        To: bolger@yahoogroups.com
        Subject: [bolger] Re: Micro rudder

         


        correcting myself... actually, the high aspect rudder doesn't reduce the amount of drag, it just changes the "gear ratio" so to speak of the steering

        so it doesn't have much effect on speed but it does lighten the helm drmatically... the longer and skinner the blade, the less leverage the blade has over the relatively longer tiller

        --- In bolger@yahoogroups.com, "etap28" <dave.irland@...> wrote:

        >
        >
        > I'll tell you what's
        funny about those traditional catboats... if you make a high-aspect rudder, a typical modern blade, the weather helm is mitigated hugely. Obviously if you have a "barn door" sticking out the back, with about the same lever arm pulling against the tiller as the tiller is pulling back, it's gonna hurt--especially with a low aspect sail sticking out over one rail about 20 feet.
        >
        > Also, if you wanted to make a clever semi-balanced rudder, of a type
        Bolger actually used on a lot of his designs, you could totally eliminate the weather helm and hide that force vector in sideways torque against the rudder shaft
        >
        > I used to preach this all the time to the traditionalist
        cat boat types but nobody was all that interested . . . (PS I actually know first hand that it works. I've had a few catboats, including a Woods HOle Spritsail boat, one of about 3 in existence, and I made a nice foil shaped kick up rudder for it and it sailed like a bullet... the absence of massive weather helm obviously gets rid of a lot of drag).
        >
        >
        >

      Your message has been successfully submitted and would be delivered to recipients shortly.