S2 6.7 Junk Rig Conversion

  • 10 Aug 2021 11:27
    Reply # 10922071 on 6872873

    On the subject of lifelines..which probably should be a separate thread…think what happens if you go over the side sailing singlehanded.

    I understand that at  speed, with most harness lines, you will be dragged alongside with your head under water, unable to reach the gunwale.
    I use a long line that allows me to flat behind the stern, linked to this line is a thin line that lifts off the autopilot and releases the jib sheet. 

    A low attachment point, such as climbers use, should drag you feet first, hopefully with your head out of the water.  That said my life jacket has an integrated harness so I use that. 

    I have to admit I never put these theories to practice.  It will be interesting to hear from anyone who has been over the side.

  • 10 Aug 2021 07:53
    Reply # 10921808 on 10921277
    Scott wrote:

    I usually wear my inflatable PFD with an integral harness when I sail any further than the distance I think I can swim. But it is not all that comfortable, tends to snag on the lines sometimes and now that it is August it is just too hot to wear all the time.

    I looked into buying a purpose-made harness and tether. The prices reminded me why I don't already have one.

    So, I did my best to imitate a simple harness using the thread and seatbelt webbing left over from making my sail. It is not perfect, but it was basically free. It only took me about an hour on the sewing machine to make it. I feel safer wearing it. I hope my feeling is right!

    If you can't tie a knot, then tie a lot. That goes for stitching too, right?

    I am trying to get into the habit of wearing my inflatable PFD whenever I am out on the boat by myself. I don't find it too uncomfortable to wear. If sailing in rougher weather I will also use the harness attachment. It is so easy to fall off a small boat which does not have any life lines, but having reached the ripe old age of 68, and still wanting to enjoy a few more good years of sailing, and life, I think I would be pretty pissed off with myself if I fell overboard with no PFD, and drowning was imminent, and I could have avoided an untimely end by just wearing my life jacket and harness. 
  • 10 Aug 2021 01:58
    Reply # 10921277 on 6872873

    I usually wear my inflatable PFD with an integral harness when I sail any further than the distance I think I can swim. But it is not all that comfortable, tends to snag on the lines sometimes and now that it is August it is just too hot to wear all the time.

    I looked into buying a purpose-made harness and tether. The prices reminded me why I don't already have one.

    So, I did my best to imitate a simple harness using the thread and seatbelt webbing left over from making my sail. It is not perfect, but it was basically free. It only took me about an hour on the sewing machine to make it. I feel safer wearing it. I hope my feeling is right!

    If you can't tie a knot, then tie a lot. That goes for stitching too, right?

    2 files
    Last modified: 10 Aug 2021 02:00 | Anonymous member
  • 17 Jul 2021 16:03
    Reply # 10757957 on 10756077

    I should learn to draw :)


    actually your drawing is very clear. Being easy to do and better looking than  most freehand (well mine anyway) should encourage its use.
  • 17 Jul 2021 08:16
    Reply # 10757423 on 6872873


    Scott,

    Boats with a spade rudder and no skeg are inherently course unstable. Your boat is, and so is Weaverbird

    A self steering gear for such boats must add the stability that is missing.

    The OGT does not do this. A trim tab does not do this.

    Both might give adequate steering with the wind forward of the beam, because then the combination of sail, hull and and rudder tends to have stable characteristics (where the hull and rudder alone do not). Neither would work off the wind sufficiently well off the wind to be worth the effort of making them. 

    An auxiliary rudder gear (the Hydrovane is a commercial example) adds stability to a certain degree, because the main rudder is fixed and acts as a skeg.

    Only a servo pendulum gear does a fully reliable job of adding the yaw damping feature that such boats need to make them course stable. And even then, I have found that unless the servo pendulum has an inclined axis so that it tends to trail and self-centre, small boats with dinghy-type spade rudders will not hold a steady course on a run. I have known this since the early 1970s, when I was working with Blondie Hasler, trying to get a Hasler SP servo pendulum gear (with vertical axis vane and horizontal axis pendulum) to work on Pilmer, his Kingfisher 20 with a balanced spade rudder.

    That is why I developed the two pendulum gears for which there are drawings in  https://junkrigassociation.org/members_files > drawings > David's vane gear drawings.

    I have to recommend that either you build one of these, or you take the easier option of installing an electric autopilot. For short passages in good weather, the latter should serve reasonably well.

    Last modified: 17 Jul 2021 08:30 | Anonymous member
  • 16 Jul 2021 16:09
    Reply # 10756077 on 10755158
    Annie wrote:

    My trim tab plus vertical vane, on FanShi, is brilliant.  And not expensive or requiring any welding skills.  Can you do.something similar?

    Annie,

    A trim tab and some sort of vane seems like the right answer.

    The problem I see, when I imagine building this, is the kick-up rudder.

    If I have a trim tab attached to the rudder in the water and the top of the trim tab stock attached up above the pivot where the rudder kicks up then something is going to bend or brake if the rudder swings up.

    Is there a simple solution to this that I don't see?

    I should learn to draw :)


    1 file
    Last modified: 16 Jul 2021 16:10 | Anonymous member
  • 16 Jul 2021 15:58
    Reply # 10756062 on 10753964
    Arne:

    Scott,

    Test 1
    you could for instance drive your boat for motor in a straight line. Then you put the engine in free and leave the tiller. If the boat starts swinging into a steeper and steeper turn, to this or that side, then it is unstable.

    Test 2 (..if the boat went straight in test 1):
    Motor into a medium steep turn, set the engine in free and let the tiller go. If the boat straightens out the course, then it is definitely course stable.

    The quicker the boat straightens up, the better is the course stability.

    Arne

    I went out to my boat right around sunset yesterday. There was almost no wind and Lake Macatawa was very calm. I think there was just one power boat that briefly threw a wake across the water.

    Test 1: The boat goes straight after I put the engine in neutral and let go of the tiller.

    Test 2: The boat never straightens up. The tiller stays more or less where it was when I let it go, until the boat has turned around and slowed down. After slowing down, the tiller moves and puts the boat into a steeper and steeper turn.

    So ... it is stable until something pushes the rudder over, I guess.

  • 16 Jul 2021 15:21
    Reply # 10755983 on 10755274
    Zane wrote:

    A man with good taste (he sails a Contessa 26) made his own version of the trimtab SS and proceeded to do an Atlantic circle.  Details per the video

    https://youtu.be/Wcd9Y5AS6qE

    Zane,

    I had not seen this one before. Thank you for sharing it. In my opinion the price he is asking for plans and videos is very reasonable so I purchased a digital copy.

    The only big issue I see with me building this design is that there is some welding required. It appears to be one very simple weld, but I do not personally have any of the equipment or skills.

    Last modified: 16 Jul 2021 15:23 | Anonymous member
  • 16 Jul 2021 09:24
    Reply # 10755274 on 6872873

    A man with good taste (he sails a Contessa 26) made his own version of the trimtab SS and proceeded to do an Atlantic circle.  Details per the video

    https://youtu.be/Wcd9Y5AS6qE

  • 16 Jul 2021 07:17
    Reply # 10755158 on 6872873

    My trim tab plus vertical vane, on FanShi, is brilliant.  And not expensive or requiring any welding skills.  Can you do.something similar?

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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