Vetus hydraulic steering is 'slipping'

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Balbas

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Symptoms - straight ahead isn't always at the same point on the wheel - on a passage what was straight ahead will eventually work it's way around - only noticed because the wheel has a dent in it(!).

And when on her moorings I have lashed the wheel in amidships, but come back to find the wheel still lashed and the rudder hard over.

The steering works as expected in all other respects, but obviously something's not quite right. I can't see any obvious leaks, but I will have a closer look tomorrow when I'm at the boat (and check the hydraulic level). Aside from looking for leaks, where should I be looking? Are there any obvious failure points?
 
Balbas said:
Symptoms - straight ahead isn't always at the same point on the wheel - on a passage what was straight ahead will eventually work it's way around - only noticed because the wheel has a dent in it(!).

And when on her moorings I have lashed the wheel in amidships, but come back to find the wheel still lashed and the rudder hard over.

The steering works as expected in all other respects, but obviously something's not quite right. I can't see any obvious leaks, but I will have a closer look tomorrow when I'm at the boat (and check the hydraulic level). Aside from looking for leaks, where should I be looking? Are there any obvious failure points?
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You will get some slippage in hydraulic steering as there would be a small seepage across the seals on the cylinder piston. This is why you cannot drive the wheel with a self steering wind vane.

It its excessive the cylinder piston seals need replacing.
 
Rogershaw said:
It its excessive the cylinder piston seals need replacing.
Click to expand...

Hmmm, well in which case how does one describe excessive?

Rogershaw said:
You will get some slippage in hydraulic steering as there would be a small seepage across the seals on the cylinder piston. This is why you cannot drive the wheel with a self steering wind vane.
Click to expand...
Which leads me to my next question. I want to add self steering - but I'm not in a position to spend £1,500 to do so. And from preference I would quite like a non battery intensive system.

What - if any - are my options?
 
Balbas said:
Hmmm, well in which case how does one describe excessive?

Which leads me to my next question. I want to add self steering - but I'm not in a position to spend £1,500 to do so. And from preference I would quite like a non battery intensive system.

What - if any - are my options?
Click to expand...

What is excessive only you can decide.

I have a monitor self steering which normally drives the wheel. I am adding a secondary rudder driven from the monitor pendulum vane.

I must admit I do tend to use my SIMRAD autopilot mare than my self steering gear as it takes less watching and adjustment.

The hydrovane also have a secondary rudder but no pendulum vane

Windpilot also have a double rudder system that is suitable.
 
Depending on your rudder, a trim tab off the trailing edge, operated by a tillor pilot, would be low consumption and could be operated by a windvane. You might need to put a valve across the pipes to the ram, so you can open it and allow the fluid to short circuit, rather than try to turn the wheel(s).
 
I also have a hydraulic vetus system. It slips a bit but not as much as yours my wheel might gain a quarter turn in 24 hours. I have a Raymarine autopilot that works very well, apart from quartering seas in anything above a F5 with two to three meter swell. Power wize it is not too hungry.

I'm looking at a Hydrovane long term, well over the £1,500 you are thinking about.
 
Balbas said:
Symptoms - straight ahead isn't always at the same point on the wheel - on a passage what was straight ahead will eventually work it's way around - only noticed because the wheel has a dent in it(!).

And when on her moorings I have lashed the wheel in amidships, but come back to find the wheel still lashed and the rudder hard over.

The steering works as expected in all other respects, but obviously something's not quite right. I can't see any obvious leaks, but I will have a closer look tomorrow when I'm at the boat (and check the hydraulic level). Aside from looking for leaks, where should I be looking? Are there any obvious failure points?
Click to expand...

Your system doesn't include non return valves and is working exactly as expected.
 
Sandy said:
I also have a hydraulic vetus system. It slips a bit but not as much as yours my wheel might gain a quarter turn in 24 hours. I have a Raymarine autopilot that works very well, apart from quartering seas in anything above a F5 with two to three meter swell. Power wize it is not too hungry.

I'm looking at a Hydrovane long term, well over the £1,500 you are thinking about.
Click to expand...

Your system includes non-return valvesn and will need a by-pass valve to work with a non-hydraulic external steering system.
 
PCUK said:
Your system includes non-return valvesn and will need a by-pass valve to work with a non-hydraulic external steering system.
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The Hydrovane he's considering has its own rudder, it doesn't try to move the main one. The main rudder should be locked in a neutral position (which might not be exactly amidships if there is weather helm).

Possibly, rather than bypass valves to let the rudder move, it might need some arrangement to lock it more positively in position? Depends how much slip there is in just the steering ram and the autopilot pump, since presumably the wheel pump is isolated by non-return valves to let the pilot work.

Pete
 
On my system I have duel steering pumps and a autopilot pump. All 3 have pilot operated non return valves and this in my case holdes the rudder in place.

With my modified monitor I can balance the boat using the main rudder to allow the monitor to work better and not require a lot of force to keep on course.

If you try to use a wheel driven wind vane allowing the cylinder to move using a by-pass valve there will be too much friction/oil resistance to operate nicly. You need to reduce the friction in a wind vane system to have the sensitivity needed
 
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prv said:
The Hydrovane he's considering has its own rudder, it doesn't try to move the main one. The main rudder should be locked in a neutral position (which might not be exactly amidships if there is weather helm).

Possibly, rather than bypass valves to let the rudder move, it might need some arrangement to lock it more positively in position? Depends how much slip there is in just the steering ram and the autopilot pump, since presumably the wheel pump is isolated by non-return valves to let the pilot work.

Pete
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Ah, right didn't know that. In that case his system will be fine.
 
Just to add to the possibilities. I fitted an unusuall type of wind vane (to me..) It had tubular sockets bolted either side of the top of the rudder, into which slid two tubes, cross braced, extending back past the transom. A vertical tube on a ball joint mounted on the transom passed through the loop at the end of the tubes and had a vane/paddle on the end. The tube was twisted by a vertical pivoted wind vane, so the paddle turned the rudder by swinging port or stb, as controlled by the wind vane. Sounds a bit Heath Robinson, but they left for the Azores and reported back that it worked well.
Point being, boat was around 60ft, had hydraulic steering and a poop extension that well overhung the actual transom. I had to extend the tubes to get the system to line up. Rudder was under the boat, not transom hung.
As for cost of such a system, there was nothing there that I could of not run up in a couple of days, very low tech.
There is a website. I will ask the owner if he can send a reminder.
 
I think I'm more confused than ever. I'm not sure whether I have a non return valve or not, or how I tell. Nor what type of self steering I should be looking at.
 
Balbas said:
I think I'm more confused than ever. I'm not sure whether I have a non return valve or not, or how I tell. Nor what type of self steering I should be looking at.
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Does the rudder back-drive the wheel? Ie, if a wave or whatever moves the rudder, and you're not holding the wheel tightly, will it move on its own? If so, there are no non-return valves - the fluid can move either way so either the wheel moves the rudder or the rudder moves the wheel.

If you add an electric autopilot that works by a hydraulic pump, part of the installation process will involve adding valves. Otherwise, when it pumps fluid trying to move the rudder, it will just spin the wheel instead because that moves more easily and the fluid can go either way.

An electric autopilot that works by directly turning the wheel won't need any hydraulic changes - it moves the wheel just as if you'd done so by hand and nothing else changes. I'm personally not keen on this kind of pilot though because it adds no redundancy - normally a below-decks pilot provides an alternative to at least some of the wheel-steering system.

An electric pilot that operates directly on the rudder stock is a third possibility; it would need the hydraulic system to be back-drive-able either by spinning the wheel (no valves) or by adding a bypass valve to let the fluid shortcut most of the system when the pilot was driving. I don't know how much drag a typical backdriving hydraulic system creates and hence how necessary the bypass valve would be.

For mechanical self-steering, you want one that doesn't operate on your main wheel, because of the creep. The Hydrovane fits that bill nicely; the system described by DownWest would do too, though I don't think it's a commercially available product (I have seen pictures of the same approach on a smaller boat, but suspect it's probably a plan in some 70s book that a handful of people have made one-off versions of). I think there's another type that has both a servo pendulum and its own rudder and again that would work.

I have no personal experience with windvanes but I like the look of the Hydrovane as a compact self-contained unit that doesn't need lots of "rigging" around the boat - the working mechanism has an air of "engineering instrument" where some of the others have "contraption" (even if they're efficient and generally reliable contraptions). It's been around without major change for many decades and still seems to sell well.

Pete
 
DownWest said:
But that still leaves having to lock the rudder to avoid the 'creep'. So valves in the hydraulic pipes, within easy reach.
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No because the non return valves would keep the rudder in place unless there is excessive creep or no non return valves.

This is how mine works my rudder stays put when left alone, creep does happen when the steering is operated but not when stationary.

We do need to know if the OP system has non return valves or not
 
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