Raymarine ST2000+ tiller pilot problems

[CPD]

I have had one for nearly 2 years and have started to have problems in that the main drive shaft seems to unscrew itself from the workings within. If that doesnt happen, then the plastic "nut" on the end of the shaft unscrews from the shaft. Either way, loss of control is the end result. In the recent past I have put a drop of threadlock on the female thread to keep the innards attached. Yesterday the shaft parted from the innards, and within a couple of hours after re-assembly, the grey nut worked loose. The problems seem to surface when the unit is being used in "heavier" seas - flat water with no waves seem not to be a problem. The unit is well within boat weight spec, and other than these issues, I have to say, it has been an excellent bit of kit. Has anyone had a similar experience, or any comments in general ?.

 

[DaveS]

I have two of these, one to act as a spare when the first breaks down - which it occasionally does! I haven't had your particular fault, but have had:

1. intermittent erratic steering. Turned out to be a broken O ring that had got itself jammed into the compass gimbals

2. mechanical failure when the plastic bracket that holds the "inside" shaft bearing sheared - an interesting cone shaped break. An attempted fix with glue failed instantly, and I now have it reinforced with an aluminium plate that I made up: took time, but I think it's now stronger than with the original arrangement.

3. electronics failure from water ingress. This is a commonly reported problem, but (a) you get prior warning (condensation inside the window), and (b) it's time consuming, but fairly easy, to fix by taking it apart and drying everything out. This happened to me again a few days ago after some very wet weather and I am currently thinking of making it a little canvas raincoat with a transparent patch over the buttons and display...

Having said all of that I still think it's basically a good machine.

On your symptoms I would have thought securing the plastic ram end should be fairly easy either using glue or just screwing it tighter (taking care to only grip the part of the ram that stays outside the seal when fully "in". The inner end coming undone sounds more worrying, and I wonder if there is any possible link with my problem 2. above?

 

[Ruffles]

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1. intermittent erratic steering. Turned out to be a broken O ring that had got itself jammed into the compass gimbals


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I had that on mine
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3. electronics failure from water ingress.


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Methinks 1. and 3. are related. The 'o' ring is from the shaft seal. I haven't replaced the one that failed on mine - I should do so. Perhaps a letter to raymarine might produce some replacements. I suspect that the shaft needs to be kept lubricated to prevent it shredding the rubber.
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I am currently thinking of making it a little canvas raincoat with a transparent patch over the buttons and display...

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If the failed 'o' ring is the cause then the water will be running down the shaft into the unit. Hard to prevent this with a cover unless it extends up to the rudder.

 

[AngusMcDoon]

I made a raincoat for a ST2000, posted a pic here, and everyone laughed because they said it looked pink. Harrumph!

 

[DaveS]

Sorry about possible confusion. My broken O ring came from the inside end of the shaft - beside the bearing that was released when the bracket sheared, i.e. there are grounds to suspect that my mechanical faults 1 and 2 may well have been connected.

The seal that the shaft slides through, and which is meant to keep the rain out, is integral with the seal between the two casing halves: it's all a single piece of "rubber" which forms separate lip seals on the shaft and casing parts.

 

[DaveS]

That's almost exactly what I had in mind! How do you find it works?

 

[Ruffles]

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Sorry about possible confusion. My broken O ring came from the inside end of the shaft

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That sets my mind at rest! I couldn't find where the thing had come from!!

Sounds like a cover for the autohelm is in order then. SWMBO will think I'm mad. She laughed at the bag I made for the washboards.

 

[john_filer]

I've had the exact same problem.
The 'O' ring secures the inner end of the thrust arm to a sliding block. i.e. the arm is pushed through a hole in the block and then the 'O' ring locates in a groove in the end of the arm to prevent it being withdrawn.
The block slides along two parallel bars and it's purpose is to resist any lateral forces applied to the arm.
The 'O' ring in my unit disintegrated and I suspect this was because it is abraded if the arm is manually rotated around its axis.
The 'O' ring is within the unit and is not any part of the surface waterproofing. A flexible rubber gasket between the two halves of the unit also includes an orifice through which the arm passes.
To help the gasket resist water you could apply a coating of silicone grease ('O' ring sealant) , the cheapest source of which is the pipe sealant sold for plumbing.

A replacement 'O' ring direct from Raymarine (www.raymarine.com) is around £3 plus post and packing.

 

[Wai_Tapu]

Well, I hope number 3 is the cause of my very badly timed failure on Saturday morning. A HUGE swell whilst entering into Weston Bay (wind against tide) came straight over the sprayhood and half filled the cockpit and instant non functioning of autohelm. Still displayed course but no actuation of motor. Made subsequent tacking across the channel to Barry quite exciting single handed /forums/images/graemlins/tongue.gif! Will be taking apart tonight to see what's what. Thanks to all above for info.

 

[Wai_Tapu]

Well, got the tiller pilot apart last night, and although there was a few traces of damp inside, the cause of failure was actually that the drive belt had jumped off. Must have been the shock of a ton of water landing on it. Have dried out and reassembled but not had a chance to try on the boat yet, so fingers crossed.
Does seem rather easy for the belt to slip off, though. /forums/images/graemlins/frown.gif

 

[DaveS]

Good luck with the fix - I've not had the belt jump off yet, but others posting here have.

Have you checked, e.g. tasted, your internal moisture (no smutty remarks, please!)? If it was a big dump of sea rather than rain that caused your problem you might just have salt water inside which is much more serious. If so you really should rinse it all out well with clean fresh water (or a fresh water / alcohol mix if you're in a hurry) before thoroughly drying out. I would have a look too at the PCB and gently rub off any encrustations before the final rinse.

 

[notyet]

I think I have suffered from number 3 also, we had persistent rain during the delivery trip a few weeks ago - the thing made a strange beeping sound and stopped working. Thnking back I do remember condensation in the window.

I have ignored it since as there were more pressing issues but last weekend I tried it out again, it all seemed to be ok until I set it to auto when it just sat there and did nothing.

I'll try dismantling it later, fingers crossed it is something obvious/cheap to fix!

 

[Plum]

Great picture of raincoat. I have made one too and will post a picture if I can find out how. How do I post a picture like you did?