Wind Vane drawings

[barnaclephill]

The missing link in Barnaclephill's list is PBO 400, April 2000. This is Geoff Bakers article on his servo unit using bevel gears. The principal is the same as all the bought ones but Geoff has constructed his unit in such a logical method that its operation is easily understood. Its also more mechanically efficient than the bought ones which sometimes sacrifice efficiency for style..

Is the missing link my reference number 8, written by Geoff Baker, as here attached in resized small scans? I have no date on the page footnote, so it may have been from a secondhand PBO that I bought from the boatshop.

This unit uses the bevel gears from an old-style hand "egg beater" drill to transfer the up-down of the aerofoil into the rotary motion for the paddle.

All available via as scanned. Just ask

 

[fishermantwo]

Is the missing link my reference number 8, written by Geoff Baker, as here attached in resized small scans? I have no date on the page footnote, so it may have been from a secondhand PBO that I bought from the boatshop.

This unit uses the bevel gears from an old-style hand "egg beater" drill to transfer the up-down of the aerofoil into the rotary motion for the paddle.

All available via as scanned. Just ask

That's the one. Geoff uses an old hand drill bevel gears but these days with the internet Acetal or brass gears are easily available as are ss ball bearings. Geoff's version uses plastic bearings but ball bearings in pillow blocks could easily be substituted. Geoff also has an extra refinement of a counterweight on the lower transmission lever.
Good site for parts. https://sdp-si.com/eStore/

 

[Rigger Mortice]

I knew I had a link somewhere......

Try this http://windvaneselfsteering.com/?q=content/walt-murrays-website

 

[Poignard]

If you can get there tomorrow, there is one on the Amateur Yacht Research Society's stand at the Beale Park Boat Show now. It's the pendulum type and made by a AYRS member

Tomorrow's the last day of the show

 

[maxi77]

The AYRS publish a book on the subject and have many past articles as well, may well be worth the subscription if you want to build your own.

 

[barnaclephill]

windvane scans

I'm uploading most of these scans to photobucket now:

http://s1136.photobucket.com/albums/n491/barnaclephill/

for easier access

 

[Ross D]

Apart from the ability to pack a servo pendulum away, what are its advantages over a trim tab auxiliary rudder mounted on the transom. Surely the extra rudder is an advantage in terms of safety in long passages.

Does anyone know if servo pendulum wind vanes perform better than trim tab auxiliary rudders. They are cheaper which I suppose is why everyone uses them now but are they better?

 

[vyv_cox]

I think this question is answered in the free book I linked above.

 

[Ross D]

The link is a very comprehensive free book, but doesn't really compare the different wind vane systems, simply listing the advantages of each. There is a huge amount of information on commercially available systems, but the OP like me is planning a DIY wind vane system. What is clear is that the choice is really between a Servo pendulum and an Auliliary rudder with a trim tab as the other systems are too complicated to make or simply do not work well enough to bother with.

Does anyone know if the advantage of an emergency rudder, coupled with no steering lines in the cockpit (ideal for me with small children in a relatively small boat) offsets the complexity and weight of the auxiliary rudder or is the servo pendulum's light weight and small design the best?

 

[fishermantwo]

The link is a very comprehensive free book, but doesn't really compare the different wind vane systems, simply listing the advantages of each. There is a huge amount of information on commercially available systems, but the OP like me is planning a DIY wind vane system. What is clear is that the choice is really between a Servo pendulum and an Auliliary rudder with a trim tab as the other systems are too complicated to make or simply do not work well enough to bother with.

Does anyone know if the advantage of an emergency rudder, coupled with no steering lines in the cockpit (ideal for me with small children in a relatively small boat) offsets the complexity and weight of the auxiliary rudder or is the servo pendulum's light weight and small design the best?

There really is only two choices. Hydrovane type or servo pendulum. The Hydrovane does offer an emergency rudder but compensates for lack of power by a larger vane. The disadvantage is the large rudder or oar when not in use makes the yacht harder to sail and awkward to reverse. They are also very expensive but they certainly have their fans.
For the normal run of the mill fin keeler or long keeler the servo pendulum is the best bet. Either bought or self built when set up they will easily outsail a good helmsman. The biggest problem I have is trying to not sit in the cockpit and watch it operate, it tends to be mesmerising. When not in use the oar just finds its own position in the wake. Never tried reversing with the oar blade down. I find that my unit will steer the yacht even when motoring with the sails down, the relative wind and water flow enough to supply ample effort. With the headsail furled and the main lowered into the lazyjacks/sail cover the vane will steer the yacht on a close reaching course in a moderate breeze.
Youtube has plenty of examples of windvanes and search out files from www.sailsarana.com. There are several pdf files from this author and they are worth seeking out.
Really you can spend from $20 for a homebuilt pvc pipe up to $7000 for a Hydrovane!

 

[Ross D]

Just looked at the hydrovane, it is just a straight rudder therefore it is needs a vane almost as big as the rudder to make it do anything. A balanced auxiliary rudder with a trim tab needs a smaller vane, but it is better than a servo pendulum?

I still have no idea what to build this winter!

 

[rob2]

Choosing a windvane is largely a matter of a series of eliminations, based on the configuration of the boat itself. With a transom hung rudder you have the option of a trim tab system - a neat system and usually works well with the possible exception of running in light airs, when there is insufficient wind over deck to hold a steady course.

Auxiliary rudder systems can be either direct or trim tab and have similar qualities but with the advantage of offering an emergency rudder.

The real difference with the servo pendulum concept is that the wind controls the gear, whilst the power is derived from the water flow over the paddle - it is generally considered to be at least ten times more powerful than any other system. As boat speed increases, the power to the tiller increases proportionally. When running, the power is still available proportional to the speed through the water. Many long-distance cruisers also use a small tillerpilot linked to the windvane to harness the power of the servo pendulum for steering, even under engine.

I have several acquaintances who find the Hydrovane very useful and particularly easy to set up as the main rudder can be locked to offset weather helm. If you're going to build your own vane system, though, I would suggest an achieveable design would be based on the Walt Murray types, Jan Alkema, or that shown in the Bill Belcher book.

Rob.

 

[Blue Fox]

Have a look at the Holland Windvane: http://www.hollandwindvane.com/
You can order all the stainless steel stuff at the seller and build it yourself. OK, it would take a long winter, but it is doable for an amateur.

 

[SvenH]

Also on offer on the mistervee site:

http://mistervee.com/?q=free-plans-os-walt

 

[fishermantwo]

Just looked at the hydrovane, it is just a straight rudder therefore it is needs a vane almost as big as the rudder to make it do anything. A balanced auxiliary rudder with a trim tab needs a smaller vane, but it is better than a servo pendulum?

I still have no idea what to build this winter!

Well the Hydrovane is a bit more complicated than that. In that "box" is a sort of gearbox with variable ratios around 2:1 or 3:1 depending on model. It uses a lever to alter the ratios
where as servo pendulums use either a lever or bevel gears. The unit depends on prebalance of the rudder blade because the vane lacks the power of a servo unit. Servo units also have a prebalance on the oar/water blade too.

If your vessel can use a servo pendulum, check out all the manufacturers websites and go through the photos, then build a Walt Murray design. The only decision is what materials to build from. Plastic, stainless steel or timber, either ply or solid wood or any combination. What ever your comfortable with. All the components are easily sourced.

 

[barrow_matt]

This excellent thread has given me plenty to read as I am also considering a wind vane steering project for my little 19' boat. I'm looking at the servo pendulum systems and it all makes sense except for one part, the way it moves.

I'm a computer programmer and electronics geek so gears, pivots and crankshafts are all a bit alien to me but I would like to think my all-round engineering ability is reasonable.

I've been watching this video: http://www.mistervee.com/?q=How_servo_pendulum_self_steering_works

The bit I can't work out is the mechanics of how the bottom section is able to swing with the water without putting a reverse force through the gears back to the windvane? See 0.38 - 0.53 in the video.

 

[rob2]

When the paddle swings, it simply rolls around the vane drive gear and in doing so it also progressively rolls off the original angular setting so that it doesn't simply continue trying to steer. As the boat turns back on course, a little opposite effect on the vane is enough to make the oar swing back to the centreline. This progressive cancellation of the original input is what is referred to as feedback - once the tiller has been moved, the input is cancelled.

There are two forces in ply - the air pressure on the vane as the boat goes off course turns the paddle blade, but it is the water force which causes it to swing and pull the tiller.

Rob.

 

[SvenH]

Indeed. And to go a bit further, the strongest wins.

The system is designed so that the windvane can rotate the rudder around the vertical axis. In doing so it overcomes the friction that is present in the pendulum rudder bearings. Now if those bearings were to seize while the pendulum is swung out and then is swung back to the centre by a wave or movement of the boat, then it would move the windvane.

But as described by Rob, that normally does not happen.

 

[Spuddy]

I had a look at a homebuild on hydrovane lines - an auxiliary rudder with a trim tab. Built on the dockside in Spain somewhere using scrapyard resources. The pole that supported the vane was thickwalled alu revolving in a nice fit bit of pipe cunningly jubilee clipped to the pulpit ; so to set up, just stretch a hand out of cockpit and twist the inner pole until vane feathers. The rudder was stuff lying around : a slab of grp thickened and extended with ply; can't remember the hinging details but it was a simple solution to the reverse counter problem. Trim tab was more ply hinged using the Wharram cat rudder idea of rope threaded thro holes. Tab and vane connected by fishing line!
The whole thing was a mile away from the aero-engineered approach but had worked well for several thousand miles. Sure, it didn't have the immediate power of a servo pendulum but operated more as a "nudger".
A polite approach to Clarissa on Storm Petrel at Woodbridge would give you a guided tour I'm sure - she spent ages explaining it to me.

 

[janalkema]

wind vane article scans

In the posting of 9-6-11 is mentioned :

6. PBO 481 Jan '07 Jan again: "A new way with a windvane" USD aerofoil with trimtab on outboard rudder.


Just a small correction. The article describes an USD windvane and a RHM pendulum on the outboard rudder. (RHM= rudder head mounted)

Jan