capnsensible
Well-Known Member
I just moved the ladder.
Windvane steering for Moody 33
- Thread starter sadlersailing
- Start date
Tradewinds
Well-Known Member
Why bother in the 1st place when it works 100% offset? If it compromised its performance I would have done the same but the original designer/engineer said it wouldn't - and it doesn't.
Ah well, different strokes for different folks
macd
Well-Known Member
1. Fact is, the action of water moving over a blade provides far more force than wind on a vane until wind speed becomes very high. I suspect you know this to be true: tell me, when rowing a boat, do you attempt to engage the water on the power stroke, or the air? I imagine you've worked out that one is quite a bit heavier than the other and offers rather more thrust.
2. Myself and others have already indicated which systems utilise their own rudder. Like the Hydrovane, none of them requires lines to the tiller/wheel: the rudder dedicated to the windvane system does the steering. The lack of "unecessary" lines is by no means confined to the Hydrovane system, nor to the principles on which it works.
3. Too-small rudders? Nonsense. All the wind vane systems which employ their own dedicated rudder have a very substantial one, similar in size to the Hydrovane's. Surely you can't me mistaking servo blades for rudders? If so, whatever your expertise with the Hydrovane (which I don't question one bit), you are in no position to offer views on servo-pendulum systems, since you don't have a clue how they work.
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Poignard
Well-Known Member
The following is from the Monitor manufacturer's website:
Quote from email received from Andrew Wilkes, February 2005:
"In 2003-2004 we sailed from the UK, around South America and back - a logged distance of 20.000 miles. Most of this trip was under sail and we used the Monitor self steering for most of the time. We lost our [boat's] rudder in the South Atlantic halfway between Estrecho de Magalles and Buenos Aires.The MRUD was rigged and steered us the remaining 500 nm to Mar del Plata in Argentina. We could, literally, have been lost without it."
KellysEye
Well-Known Member
> Fact is, the action of water moving over a blade provides far more force than wind on a vane until wind speed becomes very high. I suspect you know this to be true:
Of course it's true that's why Hydrovanes have large 'sails' for light airs. I wouldn't say that the wind has to get very high given that the increase in the wind's pressure is the square of the increase in wind speed - 10 knots having twice the pressure of 5 knots, with fifteen knots being nine time the pressure of 5.
I'm fully aware of how servo pendulum systems work, we researched them. Then rejected them. Everybody to their own I suppose.
Of course it's true that's why Hydrovanes have large 'sails' for light airs. I wouldn't say that the wind has to get very high given that the increase in the wind's pressure is the square of the increase in wind speed - 10 knots having twice the pressure of 5 knots, with fifteen knots being nine time the pressure of 5.
I'm fully aware of how servo pendulum systems work, we researched them. Then rejected them. Everybody to their own I suppose.
Baggy
Well-Known Member
I think hydrovane is brilliant
nuff said...
nuff said...
macd
Well-Known Member
1. Looks like you're not one to offer lessons in square law maths, either.
2. If you're fully aware of how servo pendulum systems work, how could you possibly have come to the conclusion that dedicated rudder systems other than the Hydrovane have a rudder "too small to be effective"? Poppycock.
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Williwaw
New Member
Are some of us developing too great a head of steam here?
The original Sailomat and a current model in the Windpilot range are servopendulum windvanes where the servopendulum oar drives their own full auxiliary rudders. Other servopendulum types drive the boat's own rudder via lines to the tiller or wheel. With the latter, it is harder to achieve a low friction and sensitive (stretch-free) layout of the lines on a centre cockpit yacht than an aft cockpit one - which is what the first post in this thread was about.
The Hydrovane is the only successful vane gear where the air vane drives a full auxiliary rudder directly. It has been in production for 40 years, with few modifications from the original design, and so total production is probably numbered in thousands rather than hundreds. It works, as all its happy owners attest, just as well as the servo types. It works well because of a number of design features: it has a balanced rudder which needs less power to turn it; there are no control lines to lose power and sensitivity due to friction and stretch; and it has ways of altering the ratio of the air-to-water connection and the inclination of the air vane's axis, both of which allow the gear to be tuned to varying conditions.
I bought a Sailomat 601, which has a servopendulum connected to the yacht's tiller/rudder. Why? My main criteria were ease of removal, for security on my mooring; light weight because of the long overhang of my yacht's counter; and light airs performance. Aries and Hydrovane lost out due to weight. Windpilot was a contender on the first two criteria but Sailomat has a patented feature to adjust the air-to-water ratio which I hoped would improve the sensitivity in light airs. I have not been disappointed but I am sure that I would have been happy with a different choice.
Personally, if I had a centre cockpit yacht like the originator of this thread, the Hydrovane would be high on my list for its ease of installation.
The original Sailomat and a current model in the Windpilot range are servopendulum windvanes where the servopendulum oar drives their own full auxiliary rudders. Other servopendulum types drive the boat's own rudder via lines to the tiller or wheel. With the latter, it is harder to achieve a low friction and sensitive (stretch-free) layout of the lines on a centre cockpit yacht than an aft cockpit one - which is what the first post in this thread was about.
The Hydrovane is the only successful vane gear where the air vane drives a full auxiliary rudder directly. It has been in production for 40 years, with few modifications from the original design, and so total production is probably numbered in thousands rather than hundreds. It works, as all its happy owners attest, just as well as the servo types. It works well because of a number of design features: it has a balanced rudder which needs less power to turn it; there are no control lines to lose power and sensitivity due to friction and stretch; and it has ways of altering the ratio of the air-to-water connection and the inclination of the air vane's axis, both of which allow the gear to be tuned to varying conditions.
I bought a Sailomat 601, which has a servopendulum connected to the yacht's tiller/rudder. Why? My main criteria were ease of removal, for security on my mooring; light weight because of the long overhang of my yacht's counter; and light airs performance. Aries and Hydrovane lost out due to weight. Windpilot was a contender on the first two criteria but Sailomat has a patented feature to adjust the air-to-water ratio which I hoped would improve the sensitivity in light airs. I have not been disappointed but I am sure that I would have been happy with a different choice.
Personally, if I had a centre cockpit yacht like the originator of this thread, the Hydrovane would be high on my list for its ease of installation.
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Blueboatman
Well-Known Member
Re Macd,
Whilst I wont bother to disagree with what you say, I have owned and used both Hydrovane and Monitor.
Either will do equally well on the original posters Moody transom, both are rugged, well proven, easy peasy to fit and both respond 'proportionally' to course correction, ie they are self damping, which is all that really matters.
Thus, in action you get, when the boat is knocked off course, an initial relatively large rudder or servorudder correction applied and as the boat starts to come back on to course this corrective rudder angle is continuously and smoothly reduced to zero, which minimises yawing and thus you sail faster in a straighter line.
But you knew that.
Personal preference? Hydrovane, (but I have seen an example of even this rugged kit bent by collision). The lack of lines and friction and the spare rudder/ redundant main rudder get my vote every time.
For what it is worth I did build and crossed the Atlantic using an ( get this) ''Overbalanced, trim tab auxiliary rudder set up'', the clever bit being that the rudder, trim tab and proportional linkage from the inclined axis vane could be swung up quickly out of the water when fouled or unwanted.And it was light, lighter than a Navik, for example. And the gear could 'sense' a wave coming up on the quarter and the rudder would ( being overbalanced) react to a quartering sea before the boat was knocked off course enough for the windvane to start to deflect... There ain't many things I am proud of but that was one fine, unobtrusive peace of kit, good down to 3 knots apparent wind over the stern, and, afaik, no one builds to this design commercially even now, althouth Windpilot and others are, I believe, getting the idea of 'sensing' quartering seas. But you are still stuck with having to rope up to the main steering system.
Whilst I wont bother to disagree with what you say, I have owned and used both Hydrovane and Monitor.
Either will do equally well on the original posters Moody transom, both are rugged, well proven, easy peasy to fit and both respond 'proportionally' to course correction, ie they are self damping, which is all that really matters.
Thus, in action you get, when the boat is knocked off course, an initial relatively large rudder or servorudder correction applied and as the boat starts to come back on to course this corrective rudder angle is continuously and smoothly reduced to zero, which minimises yawing and thus you sail faster in a straighter line.
But you knew that.
Personal preference? Hydrovane, (but I have seen an example of even this rugged kit bent by collision). The lack of lines and friction and the spare rudder/ redundant main rudder get my vote every time.
For what it is worth I did build and crossed the Atlantic using an ( get this) ''Overbalanced, trim tab auxiliary rudder set up'', the clever bit being that the rudder, trim tab and proportional linkage from the inclined axis vane could be swung up quickly out of the water when fouled or unwanted.And it was light, lighter than a Navik, for example. And the gear could 'sense' a wave coming up on the quarter and the rudder would ( being overbalanced) react to a quartering sea before the boat was knocked off course enough for the windvane to start to deflect... There ain't many things I am proud of but that was one fine, unobtrusive peace of kit, good down to 3 knots apparent wind over the stern, and, afaik, no one builds to this design commercially even now, althouth Windpilot and others are, I believe, getting the idea of 'sensing' quartering seas. But you are still stuck with having to rope up to the main steering system.
fishermantwo
Well-Known Member
The hydrovane users sound just a little too religious to me. The best form of flattery is to copy. Are there any other brands that operate on a similar principle. Servo systems are all very similar in principle.
I have a home built servo set up and standing alongside the vane sailing downwind in 3 knots of wind [Hydrovane clame 3 knots down wind is fine] the pressure on the vane is miniscule. I can not imagine it turning a rudder!
I have a home built servo set up and standing alongside the vane sailing downwind in 3 knots of wind [Hydrovane clame 3 knots down wind is fine] the pressure on the vane is miniscule. I can not imagine it turning a rudder!
KellysEye
Well-Known Member
>1. Looks like you're not one to offer lessons in square law maths, either.
Oops, first one wrong second right, sorry.
Oops, first one wrong second right, sorry.
jeanpaulcopie
Well-Known Member
I've sailed round the world single handed with a Scanmar Monitor wind vane. Was OK. Sold the boat. Bought a centre cockpit and fitted a Hydovane. BEAUTIFULL.Whatever the wind-upwind/downwind. Sailed this summer single handed from Med to North Britanny via Gibraltar with Hydrovane (first experience). Expensive but worth the money. The only vane, to my knowledge that compares is the Windpilot Pacific Plus but never tried it. And both are emergency rudder friendly.
PS. If you go to the servopendulum type vane you might look at the Plastimo Navik Wind Vane. Not easy to find but around £500/600. Should be able to cope with the Moody 33. But for a centre cockpit I would definitely look for a totally independant steering gear. No lines. Nothing.
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Baggy
Well-Known Member
Hydovane. BEAUTIFULL
Bien dit monsieur
Bien dit monsieur