Naiad problem

The naiad system on my trawler had been working fine. Yesterday after getting waked from behind they now rotate to one side. In CENTER mode they are centered. When activated they rotate to one side. I thought I may have picked something up on the fins but the problem occurs when the boat is stopped.
Any ideas?


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Greetings,
Mr. M. Is the oil in the reservoir at the appropriate level? What are your gauge pressures? Do you have a manual?

Oil at mark, temp, pressure at correct level. 100 page manual written by engineers for engineers.


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Greetings,
Mr. M. Well....



Sorry...

Not sure what you mean by "rotate".
Do they work when underway? Are you making sure you have them on when underway?
Where are you located? I know a few good Naiad techs along the east coast.

Check for loose wires on the position sensor on the top of the fin.

Meridian

Did you do a re-boot where all power to stabilizers was shot off? What does the manual say under the trouble shooting tips?

meridian said:

The naiad system on my trawler had been working fine. Yesterday after getting waked from behind they now rotate to one side. In CENTER mode they are centered. When activated they rotate to one side. I thought I may have picked something up on the fins but the problem occurs when the boat is stopped.
Any ideas?


Sent from my iPhone using Trawler Forum

Click to expand...

So, to be clear, with the system on and when set to center the fin center?

When underway with the system active the fins work correctly?

When the system is off and the boat is not working the fins flop over to one side?

Hi Bill:
Never really paid much attention to the Naiad positions on my trawler while in the water, but when stored out of the water for the Winter, they did "droop" after a while. One seemed more "droopy" than the other. I figured it was the result of a slow hydraulic pressure release (not a fluid leak) past the hydraulic pump or perhaps there is some non-return valve in each line. Nevertheless, they operated just fine when Summer came around again and all indications were normal.

I have another problem but they may be related. Either the stbd piston or the actuator is leaking. The tank is drained. I'll fix that first then see what happens.

Greetings,
Mr. m. Ahhh...Could it be a seal popped when you were waked? THAT would make some sense.

Never thought of that.


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" I thought I may have picked something up on the fins but the problem occurs when the boat is stopped.
Any ideas?"

The fins flop over to one side only when the boat is stopped?

When you say the boat is stopped, do you mean the engine is stopped or still idling??
Stopped engine means no hydraulic power to activate fins. Idle means you probably have leaking pistons/seals etc preventing sufficient pressure build to set fins.

I once had a Niad hydraulic cylinder piston come loose from the shaft. The fin went over to one side, but wouldn't come back. I could tell oil was flowing because the hose was hot.

Chrisjs said:

When you say the boat is stopped, do you mean the engine is stopped or still idling??
Stopped engine means no hydraulic power to activate fins. Idle means you probably have leaking pistons/seals etc preventing sufficient pressure build to set fins.

Click to expand...

He has pressure or the fins wouldn't center when set to.

Bill:
Not saying he does not have pressure, just that the pressure bleeds away when engine (hydraulic pump) not running or running too slow at idle. Look for leaking seals, valves etc in the hydraulic lines. As previous, our fins did this during Winter storage over the course of a few months.
As for centering, the fins would not center if there is a significant pressure leak but will center otherwise when engine (pump) is running.

Chrisjs said:

Bill:
Not saying he does not have pressure, just that the pressure bleeds away when engine (hydraulic pump) not running or running too slow at idle. Look for leaking seals, valves etc in the hydraulic lines. As previous, our fins did this during Winter storage over the course of a few months.
As for centering, the fins would not center if there is a significant pressure leak but will center otherwise when engine (pump) is running.

Click to expand...

There is zero pressure when the engine is not running. Whether a seal is leaking or not. With the system shut off it is normal for the fins to move around. Unless they are pinned there is nothing to hold them to center.

And you should have full pressure available at idle if the system is working correctly.

"As for centering, the fins would not center if there is a significant pressure leak but will center otherwise when engine (pump) is running."

The only time you have pressure is when the pump is running. So I am not following what you are saying here.

Bill:
I think we are actually agreeing!!
All I am suggesting is that a leaky valve or seal in the fin hydraulic system could cause the fins to flop when the engine is not running or running too slowly to provide adequate pressure.
My fins did not flop normally with the engine off, except over an extended period (Winter).
Is this not what Meridian's concern is??
Or have I got the wrong end of the stick completely??

Well, the engine speed should not be effecting the pressure under normal operation.

And your fins didn't flop over over time because pressure blead down over time.

Bill:
Not sure what your point is!!
I agree with you that normally engine speed not an issue.
This situation is NOT normal! There is a problem somewhere.
Also, why are you saying the fins do not flop because of pressure bleed.
This suggests that they are normally in the flop mode when engine is stopped - simply not correct. Normal position is maintained when engine is stopped for extended period.
Was just trying help and do not want to get into pissing contest, so I am done here!

Chrisjs said:

Bill:
Not sure what your point is!!
I agree with you that normally engine speed not an issue.
This situation is NOT normal! There is a problem somewhere.
Also, why are you saying the fins do not flop because of pressure bleed.
This suggests that they are normally in the flop mode when engine is stopped - simply not correct. Normal position is maintained when engine is stopped for extended period.
Was just trying help and do not want to get into pissing contest, so I am done here!

Click to expand...

Geez, calm down. I'm not trying to have a pissing contest.

The OP never answered my questions directly so I'm still not sure exactly what is going on and when. We don't even know how old his system is or what upgrades he may or may not have.

Fins most certainly can/do move around when the engine is stopped if you don't have the self pinning type. I've seen it many, many times. In fact I've seen it on the boat I currently run. That is one of the reasons for the self centering feature at slow speeds. And it takes hydraulic pressure to keep them centered.

If they don't self pin and the system is off while manuvering the fins can move all around due to the force of the water pressure on them. In fact they can interfere with how your boat manuvers. And out of the water you can rotate them by hand in many cases. They might be stiff but they can be moved.

So I don't know what is normally in the OPs case.

The OP said, "In CENTER mode they are centered. When activated they rotate to one side. I thought I may have picked something up on the fins but the problem occurs when the boat is stopped. "

Does "stopped" mean engines stopped and no system pressure? Or just no motion thtough the water but the engine/s are on and the system has pressure? Do they only go over to one side when the boat is stopped but the engines are on and the system has pressure? Or any time the are set to active/on?

I don't know. Not having a complete picture of what is or is not going on and when makes it hard to give answers that are more then just shots in the dark don't you think?

If they go to center when set to center but move all the way to one side when set to active/on, I would think its not a seal issue.

It sounds more like a gyro or settings issue.