Auto pilot/auxillery Rudder

Joe · Feb 7, 2010

Why on earth would you want to do that? If you want to mount a tiller pilot on a wheel equipped boat you could probably just rig it up using your emergency tiller. Normally, on wheel equipped boats, an emergency tiller is attached to the top of the rudder post in case a steering cable snaps. You can make one out of a piece of tube stock and the appropriate connector to the tiller post.

higgs · Feb 7, 2010

Hermit - Are you doing this to hook up an auto pilot?

sailingdog · Feb 7, 2010

A lot of emergency tillers are not appropriate for use with a tiller pilot. Many require cockpit gear to be moved or rearranged. One such setup I've seen actually requires that the wheel be removed for the emergency tiller to be effectively accessible. Also, the loads on many emergency tillers is higher than most tiller pilots would effectively handle.

Joe said:
Why on earth would you want to do that? If you want to mount a tiller pilot on a wheel equipped boat you could probably just rig it up using your emergency tiller. Normally, on wheel equipped boats, an emergency tiller is attached to the top of the rudder post in case a steering cable snaps. You can make one out of a piece of tube stock and the appropriate connector to the tiller post.

Joe · Feb 7, 2010

sailingdog said:
A lot of emergency tillers are not appropriate for use with a tiller pilot. Many require cockpit gear to be moved or rearranged. One such setup I've seen actually requires that the wheel be removed for the emergency tiller to be effectively accessible. Also, the loads on many emergency tillers is higher than most tiller pilots would effectively handle.

I agree with you on that point.... the question should be, "have you considered using the emergency tiller?" Of course, I would just save up the money to get the appropriate wheel pilot instead of installing a second rudder, tiller and additional brackets to try matching up to a less expensive tiller pilot. Having to lean over the pushpit to install or remove a rudder would be entirelly a pain in the stern cheeks. Even a kcik up rudder on a boat that size would pose more problems than it's worth. Removable/kickup rudders for dinghies and beach cats are one thing, but a 30 foot cruising sailboat with a pushpit is another.

The loads are naturally higher, that's why wheels are installed.... so the tiller doesn't have to be 10 feet long... but my tiller pilot connects about 2/3 of the way up from the post anyway.. it doesn't use the full length of the tiller... so I'm sure a reasonablel modification is possible.

sailingdog · Feb 7, 2010

Joe—

I'd point out that my 28' sailboat has a kickup rudder...

Of course, it also has a board up draft of 15"... and is a trimaran...

Stu Jackson · Feb 7, 2010

Trim tab

hermit, I searched for "trim tab" and only came up with this, not the specific one you were referring to, but I do remember that thread.

http://forums.catalina.sailboatowners.com/showthread.php?p=282790&highlight=trim tab

If you can find that old thread, how about a link to it?

Ed Schenck · Feb 7, 2010

Still wondering why? Or maybe you answered it with your reference to a tiller pilot. So you are trying to use a less expensive tiller pilot instead of a wheelpilot. And you are not planning to add a wind vane that could have a tiller. A wheelpilot is a little more money but only takes an afternoon to install. And it leaves your transom clear for swimming or adding davits.

Bill Roosa · Feb 7, 2010

Aux rudder vs trim tab

That trim tab you saw with a wind vane is not a rudder for steering. It is controlled by the low power wind vane and produces the power needed to move the main rudder.
There are several ways to get your boat to steer herself without something sticking in the water. Most require surgical tubing and some light lines run to the jib. Pretty easy to set up BTW, and cheap.

higgs · Feb 7, 2010

My experience with tiller pilots is they have enough trouble steering when they have a full size rudder to work with. A trim tab type rudder, it seems to me, would offer a slower response time, which would mean corrections for gusts etc. would happen too slow to keep the AP happy.

DannyS · Feb 7, 2010

Hermit,
Here's a link to how a windvane system works.
http://www.youtube.com/watch?v=VIGqNJiS7yA
The servo pendulum rudder is probably what you saw and thought was a kick up rudder.
The servo pendulum is not designed to steer the boat by itself.

Joe · Feb 7, 2010

Hermit Scott said:
The rudder post is about 18" behind the pedastal. But that is where I need to stand. I did ask about using the e-tiller in another post. I had a solid model of the cockpit near the rudder post to demonstrate the difficulty but have since reformatted my computer and deleted it. I think Stu mentioned an auxillery rudder with a tiller pilot on it.
Anyway, I sailed by a guy yesterday that had a kick up rudder on his wind vane and started thinking about it. With my main rudder locked, it wouldn't take much of a rudder to keep it on course. I was wondering what the best position for the post in the rudder would be, forward or moved back toward the center?

Is there any rule that says the tiller has to face forward?

Hermit.... the small "rudder" is a servo-oar. It uses the water flow created by the boat to give the sensitive wind vane enough power to control the rudder. It's like a car's power steering except the water flow provides the power instead of a hydraulic pump.

Here's a link that will enlighten you: http://www.selfsteer.com/windvanes101/

Stu Jackson · Feb 7, 2010

Hermit Scott said:
1. Bill, could you please expound on what you are talking about? are you talking about running the jib sheets to the wheel? I have heard of that for self steering, and I am very interested in it.

2. Stu, I think it's this one. http://forums.sbo.sailboatowners.com/showthread.php?p=674506&highlight=hermit

Scott,

1. The links provided explain the concept. I also talked about Letcher's book in some earlier posts on self steering. The book is great and I used his methods with great success on our C25. Still working out how to on our wheel with cabintop mainsheet, would have to be the jib sheet this time.

2. Yes, that's it, great find, thanks.

Joe · Feb 9, 2010

Hermit Scott said:
It looks like it's something that would be fun to build.

Now, there's a project that would be worthwhile and save you a ton of money... as in $3000 plus. The main issue is being able to weld stainless steel and match the design to your boat. My friend on the dock here has a Flicka which he mounted a Monitor windvane on a number of years ago. I think they are about the coolest piece of equipment one can have. In that small, sturdy boat he can now sail anywhere his freshwater supply will take him.

The following link is a discussion of the merits of 3 different windvane makers. In reading it you will also understand the installation problems that may occur... and how very critical it is to match the design to the boat. http://www.cruisersforum.com/forums/f117/monitor-cape-horn-windvane-self-steering-14497.html

You'll note in the articles that some sailors have mounted tiller pilots to the servo... resulting in an all purpose steering system. This might be of particular interest to you, Hermit, because I'm thinking this is what you origianlly had in mind.

Finally, you mentioned that you just skimmed over the article I sent you... so I hope you went far enough down to read about the author's final design. This is the same design on my friend's Flicka.

Stu Jackson · Feb 9, 2010

Joe said:
You'll note in the articles that some sailors have mounted tiller pilots to the servo... resulting in an all purpose steering system. This might be of particular interest to you, Hermit, because I'm thinking this is what you origianlly had in mind.

Joe, that's exactly what I was referring to. Thanks for the link.

Hermit, read up!

Bill Roosa · Feb 9, 2010

Self steering basic concept

Hey Hermit
The basic concept behind sheet to tiller steering is as the wind increases the jib sail clew moves down wind and as it slacks the clew moves upwind. Attach a light line to the clew and run it back to the helm via blocks. Now you have a pretty powerful line that responds to the wind and by inference the boats direction with respect to the wind. Assume she bears off, the wind pressure increases, the clew moves to leeward and, with proper routing, pulls the tiller leeward and the boat heads up into the wind or back on course. The wind decreases due to the lowered pressure and the line moves to windward and pushes the tiller to windward correcting course again. Course a line can't "push" anything so you need a generous mitten full of sirgical tubing to act as a counter spring to balance the control line pull.
google "sheet to tiller"
http://www.jsward.com/steering/index.shtml