Let's talk self-steering systems...

[sailingdog]

You really need to read the classics on this subject, like Lechter's Self-steering for Sailing craft... etc...

I'd point out that the waters you sail on make a big difference... some waters like Buzzards Bay, where I sail, generally have relatively constant winds with little in the way of sudden changes in direction and as such would probably work better with wind-controlled self-steering systems. Other areas, like the Chesapeake, which has relatively fluky and changing winds, are probably less well suited for them.

[negrini]

byr0n, electronic steering has become very reliable, so it's the easiest installation. About your force calculation, mostly steering system is moved by water force, not wind. Wind will determine it's direction but enough force to move a tiller/wheel comes from the water passing through the system, and that already include some sort of purchase ratio. So, installation is always complicated and disturbing to your stern platform ....

[tager]

I do not blame anyone for having an incomplete understanding of physics. No person on earth has a complete understanding of physics. What is frustrating is listening to people talk about physics without doing any background work. It is detrimental to mankind to speak officiously when you really do not know a subject.

Some steering systems operate entirely upon energy harnessed in the form of aerodynamic drag imposed upon a vane. These are usually impractically large, barely effective, aesthetically displeasing, and only work on very well balanced boats.

Most steering systems are servo-pendulum type, with a windvane, a servo-oar, and a connection to the tiller. These work in a clever way. The vane sends energy to the oar. The oar then collects energy from the apparent flow of water caused by the boat making headway. This energy is sent to the tiller through lines guided by blocks.

There are also other varieties of self steering vanes, the most elegant of which is (imho) the trim tab on an outboard rudder.

This is a great resource when learning the basics of wind vane design.
http://www.selfsteer.com/windvanes101/index.php


Does anyone have experience with fenestrated rudders? Reportedly they require less input force from the helmsman, but have the same steering effect as a normal rudder. If this data is accurate, then they could be of great use in self steering systems.

[tager]

Also, one must remember that mechanical advantage does not increase the amount of energy input. For instance, lets say that the vane receives a Joule of energy from a wind shift. Simple machines can change both the amount of force on the tiller, and the amount of distance the tiller can be moved. However, the energy imparted on the tiller will never be greater than the Joule originally gathered by the vane.

[mitiempo]

Here's a link to plans for a horizontal vane:Sailboat Self Steering You can Build
Brian

[bartvdv]

Self Steering
Sheet-to-Tiller Self Steering

[johnnyandjebus]

I started playing around this summer with sheet to tiller steering(t-shirt steering with some thought behind it) For about 50$ you can assemble all the required equipment. I have have had mixed results. Yesterday I was out in 10-12 knots, full main and genny on my contessa 26. The sheet to tiller worked flawlessly on any tack from reaching to close hualed. Broad reaching is still a challenge. The system requies some skill/experience setting up and sail trim is key,although good sail trim is a requirement for all self steering. Gusty winds doesn't help either.
I used the page below to learn about and assemble the required parts. I recommend giving it a try even if you already have an alternative as playing with sheet to tiller steering will force you to pay attention to sail trim.

Sheet-to-Tiller Self Steering

Good luck,
John

[byr0n]

Originally Posted by mitiempo

There used to be a windvane built in England called the QME I believe (for Quantock Marine Enterprises). I can't find a picture on the web. It was a horizontal pivoting vane with a counterweight and lines to the tiller. The base was on a bearing and when sails were set you weathercocked the vane and cleated off the tiller lines. It was quite inexpensive at the time. Problem was if your boat wasn't balanced well enough it didn't work that well as it wasn't that powerful. There is also the "Mister Vee" vane produced in England currently. Those Brits like to tinker.
www.mistervee.com - Home
I believe plans are available from that link.

yes, QME. That's what I envision. Thanks for that.

Originally Posted by mitiempo

Most of the self steering systems that survived have developed into powerful reasonably maintenance free systems that work very well. The one I'm looking at is the Norvane, made in the US and quite affordable compared to the more popular names like Monitor. NORVANE Self-Steering Wind Vane. Stainless steel, servo-pendulum. Powerful, sturdy and reliable for sailboats 20’ to 60’
There is also a Windvane Forum that might be useful.
Cruising Sailor • View forum - Windvane Forum
Hope this helps
Brian

Thanks. Yeah, Norvane is a nice rig. Did you choose it for the added ability to have an emergency rudder attached? The pain is still in the $1900+ shipping and duties . Will be pouring over that windvane forum for more knowledge...

[byr0n]

Originally Posted by negrini

byr0n, electronic steering has become very reliable, so it's the easiest installation.

Yes, however an electronic steering system keeps you on a course, which is not necessarily on the wind. The wind is a fickle thing which in many places is just plain undecided so course-keeping vs wind-keeping is the big difference. Both systems will run you aground if not attended, and both will run you into obstacles without a thought if the captain is not paying attention.

Originally Posted by negrini

About your force calculation, mostly steering system is moved by water force, not wind. Wind will determine it's direction but enough force to move a tiller/wheel comes from the water passing through the system, and that already include some sort of purchase ratio. So, installation is always complicated and disturbing to your stern platform ....

yes, water is a major force... on in-water systems. (also, my calculations were in no way scientific or accurate. I simply was using bold variables to achieve a point) I am hoping to discuss the merits of above-the-water systems achieving some of the same goal that the big, sturdy expensive systems use.

[byr0n]

Originally Posted by sailingdog

You really need to read the classics on this subject, like Lechter's Self-steering for Sailing craft... etc...

Thanks Sailingdog, I am on the lookout for this book, as it is out of print, yet referenced a great deal in my googling for information of the subject of self-steering options