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Windvane selfsteering gear questions

  • 20 Aug 2011 05:37
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    Reply # 680494 on 673518
    Deleted user
    For what its worth I will start off with Bill Belcher's simple horizontal vane connected to the tiller (as Bob Groves uses). I may use a tiller pilot as back up, if I can get mine fixed..

    I'm wondering if anyone has heard of tiller pilots lasting more than 18 months??
    Is there such a beast?

    Mine is a Simrad and I've seen equally bad reports about Raymarine. Locally the word about them is, they work for a year and then thrown over board with great frustration.
  • 16 Aug 2011 11:37
    Quote
    Reply # 677358 on 676734
    Deleted user
    Jeff McFadden wrote:Is there a reasonably easy way to disconnect and reconnect the vane from the rudder for manual steering, as might be required to avoid another vessel on the lake, and then return control to the vane?

    On the Easy Go Wind vane I usually just change the angle of attack of the wind on the vane to change direction to avoid another vessel. I also use two turns and a slipping hitch on the tiller so that the lines can be immediately released if necessary. One can also use a pin on the tiller and a piece of chain tied to the lines for quick release and fine adjustment. One of the best uses I find is when gybing. I turn the vane to the new course and as it slowly changes the boats direction. I am able to sheet the mainsail in and bring it across gently. The head sail is blanketed by the main and needs no help.
  • 16 Aug 2011 11:30
    Quote
    Reply # 677357 on 676659
    Deleted user


    Robert,

    love the simplicity of the design, a couple of questions:

    - does it work ok in light winds?

    - is the design available on-line (for free)?

    - do you have drawings?

    - (applying to all wind vanes), is the vane a simple piece of flat ply? It has always struck me that if aerodynamic it would generate far more force,  say a fat double sided shape.

    cheers

    Mark

    This vane works surprisingly well in light winds, even directly from astern. By adjusting the weights one can make it even better as Arne did in a version he produced. Unfortunately I have not been able to find the design online. Highly recommend purchasing the book as the saving is immediate when you build versus buy a commercial unit. All the design info is well worth the investment. The vane itself is a piece of 1/4 inch ply with a stiffened leading edge. I would like to try a fabric covered vane over a wire frame for lightness.
  • 16 Aug 2011 06:45
    Quote
    Reply # 677315 on 677314
    Anonymous member
    Slieve McGalliard wrote:
    David Tyler wrote:Some diagnostic suggestions for misbehaving pendulum gears:
    1. Disconnect the pendulum from the rudder, and disconnect the vane fro the pendulum, or take of the vane and its balance weight.
    2. ------------

    If the pendulum misbehaves, what can be wrong? In approximate order of importance and likelihood:

    1. Hydrodynamic imbalance. Lay a straight edge in line with the vertical axis of the pendulum. It should be about 20% of the blade's chord aft of the leading edge. The hydrodynamic centre is likely to be about 25% aft, for a high aspect ratio foil. -----

    This is excellent advice David, and I would recommend anyone who is planning to set up a gear to print it off and keep as a quick reference check list. It is what I did with my friends Cape Horne gear, but it would have been useful to have an aide memoir available to save time. The gear I checked failed all of the first set of tests, and the answer seemed to be tied in with the flotation test. which it failed badly, and I didn't check the Orientation test for forward inclination.
  • 16 Aug 2011 06:27
    Quote
    Reply # 677313 on 676734
    Anonymous member
    Jeff McFadden wrote:Is there a reasonably easy way to disconnect and reconnect the vane from the rudder for manual steering, as might be required to avoid another vessel on the lake, and then return control to the vane?

    On many installations the tiller lines connect to the tiller by dropping a short length of chain onto a pin on the tiller. Look at Fig 122 in Bill Belchers book and info on page 127. To disconnect just lift the chain off the pin, and to reconnect just drop it back on. It can be an advantage to fit the pin to a small bracket under the tiller so that the chain will hang clear when disconnected.
    Last modified: 16 Aug 2011 06:28 | Anonymous member
  • 15 Aug 2011 23:13
    Quote
    Reply # 677051 on 676734
    Anonymous member
    Jeff McFadden wrote:Is there a reasonably easy way to disconnect and reconnect the vane from the rudder for manual steering, as might be required to avoid another vessel on the lake, and then return control to the vane?
    I do it by mounting a fairlead on the top of the tiller, and a pair of Clamcleats forward of that. The lines are lead through the fairlead and stopper knots are tied. It's easy to centre the tiller and the vane, if the lines are the same length. It's also easy to bias the tiller a little to windward for weather helm, leaving the vane upright.
  • 15 Aug 2011 16:08
    Quote
    Reply # 676734 on 673518
    Deleted user
    Is there a reasonably easy way to disconnect and reconnect the vane from the rudder for manual steering, as might be required to avoid another vessel on the lake, and then return control to the vane?
  • 15 Aug 2011 13:41
    Quote
    Reply # 676659 on 675410
    Anonymous member
    Robert Groves wrote:
    Jeff McFadden wrote:
    Robert Groves wrote:I've posted a picture of the Wind Vane that we use on Easy Go in my members photos. It is light, easily adjusted and has no underwater parts. It has worked flawlessly and was made up of some scrap wood, a few bolts and some line to the tiller. Total cost for the original was about $10 CDN. With two crossings of the Atlantic is is certainly the most cost effective wind vane around.


    Robert,

    love the simplicity of the design, a couple of questions:

    - does it work ok in light winds?

    - is the design available on-line (for free)?

    - do you have drawings?

    - (applying to all wind vanes), is the vane a simple piece of flat ply? It has always struck me that if aerodynamic it would generate far more force,  say a fat double sided shape.

    cheers

    Mark
  • 15 Aug 2011 06:18
    Quote
    Reply # 676435 on 673518
    Anonymous member
    Some diagnostic suggestions for misbehaving pendulum gears:
    1. Disconnect the pendulum from the rudder, and disconnect the vane fro the pendulum, or take of the vane and its balance weight.
    2. At rest, the pendulum should stay central.
    3. Get someone to sail a steady course. The pendulum should trail centrally in a stable manner. 
    4. Apply fingertip pressure to the linkage of the pendulum to induce an angle of attack. The pendulum should swing out to one side, in proportion to the amount of incidence you put on. 
    5. Take your finger off the linkage. The pendulum should centre itself, positively but not quickly. 
    6. Connect the pendulum to the rudder. With someone keeping a lookout, steer the boat with fingertip pressure on the linkage of the pendulum. If you can't do this, neither can the vane.
    If the pendulum misbehaves, what can be wrong? In approximate order of importance and likelihood:
    1. Hydrodynamic imbalance. Lay a straight edge in line with the vertical axis of the pendulum. It should be about 20% of the blade's chord aft of the leading edge. The hydrodynamic centre is likely to be about 25% aft, for a high aspect ratio foil. If the axis is too far aft the blade will vibrate, and if much too far aft it will overbalance and throw out to one side or the other. It the axis is too far forward, the blade will be hard to turn.
    2. Orientation. If the tip of the blade is pointing forward into the water flow, it is unstable, like balancing a pencil on your finger. It is better to let it trail slightly.
    3. Weight imbalance.  Swing the pendulum out to one side, so that it is clear of the water if possible. It should be neutrally balanced about its vertical axis, or should be slightly nose-heavy. If it is tail-heavy, it will tend to be unstable, throwing out to one side or the other. Sadly, many gears do not take this into account, and would be improved by having a balance weight added forward of the vertical axis.
    4. Friction. Many gears support the blade on a strong central shaft which runs in plain bearings. This is simple, but far from ideal. There needs to be minimal friction in the whole of the drive train from the vane down to the blade, and roller or ball bearings should be used wherever possible. Better is a structure that separates the bending load from the component that is turning within the bearings, so that the bearings can be of small diameter (eg, Bill Belcher's pendulum design, in which the blade is a continuous piece of wood, supported on dinghy rudder fittings).
    5. Flotation. At rest, the blade should show no tendency to float to the surface, which may happen with a deeply immersed blade made of light wood. This will introduce an instability.
    I've made a photo album of my vane gear. I hope it illustrates none of the above faults!
  • 14 Aug 2011 17:04
    Quote
    Reply # 676004 on 673518
    Anonymous member
    Jeff, I have a copy Self Steering published by The Amateur Yacht Research Society First published 1967 "Second Edition with additional gears 1970".  Although it is now a historical item rather than state of the art, it does cover the theory of the earlier designs and attempts and includes working drawings of simpler gears which are suitable for home completion.  You are welcome to have it.  Just send me an e mail with your postal address.  I don't need it; as a  I wrote elsewhere, I am very fortunate to be in a position to buy a production junk rig boat and a commercial self steering gear, tie it to the boat and go sailing ...!  Jonathan
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
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