Servo Rudder autopilot

[Phil Y]

Not sure if I have the title of this thread right, but I know what I mean. There seem to be wind vanes on the market. Although not many. And fully mechanical self steerers. And every now and then you come across someone who has retrofitted a tiller pilot to his windvane gear, and reckons it works a treat.

I reckon that makes sense. Fully mechanical systems draw a lot of power, and are fiendishly expensive. Wind vanes seem to be great for long distance cruising, in steady air, and where a few degrees off either way as the wind veers is of little consequence. But have problems downwind.

Even second hand Aries and the like to seem to fetch a couple of thousand dollars in this part of the world-and many of those are 20 or 30 years old.

Maybe what I am looking for is a "make your own" guide. What I'd like is what I think is called a servo pendulum rudder, driven by a small tiller-pilot. The tiller pilot senses a change in direction, it moves the servo rudder, the water kicks the bottom of the rudder to one side, that drives a quadrant which pulls on a rope, which is attached to the main steering wheel, which moves the main rudder. Low current draw, but plenty of power, from the force of water passing the servo rudder. The complex bit must be a two way swivel at the top of the rudder.-the rudder has to be able to turn on a vertical axis, like a normal rudder, but also kick up sideways. But not move fore and aft.

This is for 50' boat in my case. 20 tons.

Any ideas/references/experience/photos?

[wizbang 13]

Trim tab on the rudder attached to a tillerpilot. The trim tab works like a backward tiller, sometimes you see them quite a bit aft of the rudder, like a long tiller!
20 tons is a big boat for self steering.
I have hooked up a tiller pilot to my monitor. In the past, to get more power from the monitor, I have made a bigger paddle and allowed the vave part to tilt over more.
Do you have an inboard rudder? Cuz if you do, some boats put on a second rudder for the trim tab.
I just picked up 2 useb Autohelm tiller pilots for $75 at a swap meet. Folks buy them and find they are too small. hahaha

[ahp]

Did not Hestler have such a thing on his modified Folkboat "Jester" for the first single handed transatlantic race? I recall it looked very simple and he claimed it worked well.

[wizbang 13]

Blondie Hassler is credited with inventing the first servo pendulum gear. This boat has one of Hasslers gears. Very old and rare, works a charm steering this heavy 50'er. But a new servo vane is very 'spensive. I think a new Monitor is about 6 grand!! And a powerfull auto pilot is big bucks!

[Phil Y]

I have 2 rudders-both well inboard, so I can't do a trim tab. The boat used ot have an airies, but a PO removed it. Now has an electric autopilot, but it uses a lot of power, and is noisy. Plus at the moment it has an electronic gremlin-needs resetting I think-when I turn it on it turns the boat 90 degrees, and then won't hold a course. Mechanical stuff I can usually fix, electronics are black magic as far as I'm concerned. I do have a tillerpilot in a box in the shed-picked up cheap on ebay or somewhere a while ago.

[ahp]

The self steering system the Hessler used on Jester was not a pendulum. It could only be used on a boat with an outside rudder like the Folkboat The servo tab, like a rudder on a rudder, was attached to a shaft that ran up through the aft end of the tiller, aft of the rudder stock, and then had a wind vane. The angle between the wind vane and the servo tab could be adjusted, which determined the course of the boat relative to the wind. Very simple. It seemed like something that you could make yourself.

[wizbang 13]

You can still use a trim tab to a third rudder from the transom. Use /lock you main rudders to carry the windward helm.
ahp, sounds like you are talking trim tab . a servo push /pulls side to side.it is not attached directly to the rudder.

[ahp]

You can still use a trim tab to a third rudder from the transom. Use /lock you main rudders to carry the windward helm.
ahp, sounds like you are talking trim tab . a servo push /pulls side to side.it is not attached directly to the rudder.

I am talking trim tab, like airplane.

[wizbang 13]

[Phil Y]

Thanks wiz-I reckon that could be the answer. Gives me emergency steering too-which i don't have at the moment-my rudder stocks come up through the hull, to a quadrant, and are then connected by chain to a central quadrant on a vertical axis, connected by chain to the steering wheel shaft. I have nothing down below where I could attach an emergency tiller if any of that breaks. I don't quite get the connection between the trim tab and the tillerpilot. The trim tab will be moving about a bit on the free rudder, while the tillerpilot is fixed to the boat. Would you use something like a morse cable maybe?

[PeterSibley]

Phil ,do you have a copy of "Wind Vane Self Steering" by Bill Belcher?

It seems quite applicable to your boat . Lots of diagrams and detail and twin rudders doesn't seem to be a problem.

[wizbang 13]

Yes, a wee cable, like an automotive choke cable or something from a bicycle. Then the tillerpilot can be mounted in a safe place. Also the "tiller" on the trimtab sould be backwards. Details. One could knock out pronto types with dingy rudder fittings and ply. Your complicated main steering sounds like this WOULD be a ticket for you.

[ahp]

Wizbang, instead of a tiller pilot simply extend the vertical shaft from the trim tab up, and attach a wind vane. Attach the wind vane so that the angle between the tab and the vane can be adjusted, and then fixed. Hasslers's "Jester" had no electronics at all for self steering. Retain the existing tiller and let it be free to move.

[wizbang 13]

Wizbang, instead of a tiller pilot simply extend the vertical shaft from the trim tab up, and attach a wind vane. Attach the wind vane so that the angle between the tab and the vane can be adjusted, and then fixed. Hasslers's "Jester" had no electronics at all for self steering. Retain the existing tiller and let it be free to move.

Sure, no problem, well, except for the tricky linkage. If you attach it to a wind vane (horizontal or vertical) you have a conventional wind vane steerer.
Phil Y is asking about marrying a cheap tiller pilot to a big boat.
Jester did not motor in a calm either, having no motor.

[Phil Y]

Phil ,do you have a copy of "Wind Vane Self Steering" by Bill Belcher?

It seems quite applicable to your boat . Lots of diagrams and detail and twin rudders doesn't seem to be a problem.

I don't-but as above, can't do a wind vane. hence the tillerpilot idea. I'm liking this idea of a simple transom hung rudder with a trim tab driven by the tillerpitot. My transom is a little out of the water compared to wiz's pic, but thats probably OK-it might put quite a strain on the rudder fittings, and the rudder itself-I think I'd get the boat as well balanced as possible, and tie off the wheel, so as to minimise strain on the self steering rudder. Still plenty of work to do, particularly running or quartering, she can slew around a bit in a sea.

Edit-oops lost a post. I thought I'd responded to Wiz-I can't do a wnd vane as I now have davits, dinghy, solar panels and wind generator hanging off the back of the boat. She used to have an aries, with rope linkages to the wheel. Removed by a PO. (Removed by Greenpeace in fact-they owned her for a short period before the owner before me)

[wizbang 13]

I never thought I would say this , but, how about a big ass window in the transom that you can lean out of for monkeying around with it, under the dingy /solar panels/windmill. A bit tongue in cheek here , but sometimes fact is stranger than fiction. Or maybe get a real monkey trained in engineering?
I get it that you do not seek a conventional windvane.

[John B]

Phil, If you have solar and wind generator, why don't you just fix/ persevere with the auto pilot?

[wizbang 13]

John B,
downwind ,wind power fails.
at night , solar power fails. 50% of energy can be lost in storing it for 10 hours.
A towing generator is the bomb in theory, but they are 'spensive, noisy and not bulletproof.
cold beverages or sleep, that is the choice

[John B]

Those outboard leg style water generators look pretty interesting. The whole tillerpilot to vane method is really interesting to me so I'm enjoying this thread immensely. I often wonder if a tillerpilot can be geared inboard through a device or linkage/ gearing to exert more power for less effort/ less power useage. Ie a tiller operating a tiller but without the water vane.

Playing devils advocate for a minute, some would recognise this boat from my christmas cruise threads.
Contour of Cuthill. she's 3 skins of Kauri, 42 ft Birdsall design and she's cruised all around the world over many decades. South Africa , Red Sea, Canal du Midi, Atlantic and Pacific.
She's got all ' that crap on the back' but that makes her power positive enough to run an electric freezer and seperate fridge plus all the rest and she never actually needs to run her motor. She did all all her more recent world passages with a tillerpilot and one downstairs for spare.



she's 'soft' , very easy on the helm being a centreboarder but still, it can be done.

[wizbang 13]

" I often wonder if a tillerpilot can be geared inboard through a device or linkage/ gearing to exert more power for less effort/ less power useage. Ie a tiller operating a tiller but without the water vane."
whatcha got in mind? simply attaching it further out on the tiller gives more power, but less "throw". wouldn't a gear or lever thingy have the same problem?
the wee tillerpilots' suffer from a heavy tiller pushing back on them. the little arm gets pushed back in and it confuses the brain , burning out quickly, which we probably all know.

[PeterSibley]

The REAL power is the water flowing past the hull, using the tiller pilot to operate a trim tab which tells the rudder what to do seems the way to go .

What am I missing ?

[John B]

" I often wonder if a tillerpilot can be geared inboard through a device or linkage/ gearing to exert more power for less effort/ less power useage. Ie a tiller operating a tiller but without the water vane."
whatcha got in mind? simply attaching it further out on the tiller gives more power, but less "throw". wouldn't a gear or lever thingy have the same problem?
the wee tillerpilots' suffer from a heavy tiller pushing back on them. the little arm gets pushed back in and it confuses the brain , burning out quickly, which we probably all know.

Just a back up pilot. The thing is all the manufacturers are very specific about where on the tiller the thing goes but like you, it seems to me if you just put it further out on the tiller you'll lessen the load significantly,even if sacrificing some gain or scope of movement. Why wouldn't that work for steady conditions or motoring. Maybe you gain power but make the thing work more because its adjusting more?

[wizbang 13]

Exactly,
I attach my monitor lines to the end of my six foot tiller, not at the thirty inch (or whatever) they recommend.
The long keel boat needs more power and less "nervousness" .
These gizmos are made for uppity fin keelers.

[John B]

LOL. They're also made with the auto tack feature( which is probably whats gone astray on Phil's boat) which means they need the 34 degrees or so of movement designed into them by the manufacturers. But for a passage.... maybe half that would do I would think.
Mind you , on my UFK, maybe I'd be asking too much of it.

[Phil Y]

John I think you are right. On a long enough tiller a little tillerpilot should be able to keep a big boat on course in reasonably stable conditions. Certainly a handy crew member to have on board around meal times etc. Bt probably not up to tougher situations because it just won't have the reaction stength to deal with major course deviations in a timely fashion.

But my boat has wheel steering, and is basically just pretty bloody big. The helm is mostly well balanced, but in a decent wind and following sea, there's some muscle involved. Why not just persevere with the current autopilot? I will get that sorted-I have a manual and there is a long and complex 2 person process described therein to re-orient the thing. Hopefully that will work. But its noisy, and I don't know yet, because the electrics are a work in process, but I reckon you can never have enough electricity-the less draw the better. The present machine has a pretty big badass electric engine, its always going to be a hungry beast. I really like the idea of a little tillerpilot using a trim tab to steer 20 tons of boat on a couple of amps of power.

[John B]

I agree with you Phil , I spose I'm just thinking aloud myself and the thread has me wondering what I'd do to Riada as back up myself. With her outboard rudder and overhanging boom I cant have a vane and I don't want to mess up my trailing edge with a tab.

If you ever go down the replacement route , look into the Lecomble and Schmitt electric / hydraulic drives. Its a relatively expensive but grunty unit that a lot of the brand autopilots use as their drive and you'll find them on quite a few modern production boats. NKE for example. Mine's being run by the old Raymarine 6000 series computer/ control head. Mix and match.

[Phil Y]

My rudder to wheel connection is all chain, and probably no simple way to add hydraulics. My last boat had a Robertson electric hydraulic autopilot, but she had hydraulic wheel steering so that made sense. The current autopilot seems pretty robust-just has electric gremlins at the moment. I'm sure its fine. But i do want a quiet, low amp alternative. Add emergency steering into the equation and it seems like a real winner.

[keyhavenpotterer]

Have you seen Hydrovane's.

They can be positioned anywhere on the transom and give emergency steering too if you lost your rudder. They're not attached to the rudder trailing edge: they're independent.

They're supposed to be very reliable and well made/ regarded by those that have them in the UK and gone off cruising, consistently getting top marks in questionaires in mags like Yachting Monthly after trans-atlantic trips. I think its regarded as one of the best self steerer's available in the UK (but I'm no expert). No need for electrics of anykind.

http://www.hydrovane.com/

Ed

[Phil Y]

Thanks Ed-yes, they look like a nicely engineered unit.-but they have the problem of expense, and a windvane. I've gone and cluttered up the back of the boat with a set of davits. But I see on their website they suggest the use of a tillerpilot to control the rudder. Expensive solution if not using the windvane at all. It looks like quite a small rudder. Which gets me to thinking I could combine the wizbang idea with the hydrovane idea-fit quite a small rudder to the transom, maybe with or maybe without a small trim tab. Use the main rudders to get the boat nicely balanced, and the small rudder does the steering.

From Hydrovane's website-
HYDROVANE owners have installed such tiller-pilots report strong preference for them over their expensive below deck autopilots: less noise, not under a bunk, small electrical draw, saves the larger unit for a ‘rainy day’ – and a cheap way to have yet another back-up.

• Tiller style autopilot retrofit is highly recommended - for motoring and sailing in the very light winds with sloppy seas
• Needs only the least powerful units as the rudder is balanced and relatively small
• In its levered position further aft it is efficient and quiet
• Other self steering systems have variations on such a retro-fit. Only Hydrovane comes complete with a tiller in place that directly steers its own rudder - makes for the easiest to retro-fit ... and most effective .

Complete steering redundancy is achieved when both steering systems, the main rudder and the HYDROVANE each have separate autopilots.



Hmmm-maybe if I bought their rudder, plus shaft, plus brackets, that would be all I need. Interesting. or make my own.

[andrewe]

Have a read here http://www.faymarine.com/plansite/fa...e_yacht_pl.htm lots of good info, esp if you want to build your own. BTW, I am pretty sure that Blondie Hasler used a servo vane on Jester, not a trim tab. He is credited with inventing the system.
With your crowded stern, it would be possible to use a wind vane off to one side and remotely connected to the bits on the rudder (or even put it on a davit)
Andrew

[Phil Y]

Well, I've bought a Fleming system on fleabay. It'll be a while before it gets anywhere near the boat. I'm in PNG, its in Brisbane and the boat's in Tasmania. But it will happen. Looks like a nicely engineered unit, stainless rather than alloy. And they have an adapter to fit a tillerpilot.

[wizbang 13]

Flemming IS an excellent rig! I think they come in different sizes too, very high quality and robust.
My brain just cannot believe what my eyes are seeing with the hydrovane. Where does it get its' POWER?

[Phil Y]

The hydrovane rudder just looks too small to steer the boat doesn't it?