Can an autohelm linear drive unit be user cleaned?

[Raven]

I have a Raymarine autohelm system that has not functioned since I bought the boat. From the beginning, I suspected that the problem was sticking brushes in the type 1 linear drive unit. I finally got around to giving the unit a couple of smacks (the bigger hammer approach) and things freed up inside. The autohelm began functioning again, albeit somewhat intermittently. Two questions:

1) How quiet is a type 1 12v linear drive unit typically? (Mine sounds a bit like an electric motor that isn't quite getting all its juice.)

2) Is the drive unit something that can easily be serviced by the user? (I suspect that Raymarine would say no, but I'd like to hear user experiences. In particular, I'd like to get at the brushes and make sure they are making proper contact.)

[Talbot]

How old is the system. If it pre-dates the S1 system (i.e. sold as ST6000) then the new linear drive will be a stronger and more robust drive - thus worth the purchase to replace.

Raymarine customer service in UK have been very helpful in answering questions in the past so worth an email.

[Raven]

Originally Posted by Talbot

How old is the system.

I'm not exactly sure, but the date on the manual is 1999. It was sold as an ST6000 Plus (whatever the "plus" means?).

So, would the recommendation be to not open the unit up and clean up any corrosion?

We have an ST-6000 system on our 28 foot heavy displacement sloop. 1999 is probably the updated version, same as ours. The "Plus" means it has a stronger drive unit. Ours is the non-plus version and is very quiet.

-robert

[Raven]

Originally Posted by learningcurve

The "Plus" means it has a stronger drive unit. Ours is the non-plus version and is very quiet.

-robert

So, what I'm hearing when the drive operates (rather weakly) is probably the result of corrosive forces that have either made for faulty electrical connections and/or the unit is mechanically inhibited, again due to corrosion? When it does operate, it seems very eratic and weak. Ultimately, it gives a "Drive Stop" message and stops driving the rudder. This all happens under no load, flat, calm conditions.

I'm trying to decide whether to open it up myself, or send it to Raymarine for service.

I would think corrosion is the most likely culprit. I suspect that the electronics sense how much current the drive unit is drawing. If it draws too much (like motor working very hard) the electronics shuts the drive down. That is my guess anyway.

On wether to open it up or not, I would take a peek inside if it is easy to open. Besides, it is obviously out of warranty. If you send it to Raymarine, for repair, they might just send you a new (or refurbished one) anyway (after some $$$). I dont think the drive unit is the most costly (theirs) of the setup. It is just a shaft with a worm gear and stepper motor (probably).

[Raven]

Originally Posted by learningcurve

If it draws too much (like motor working very hard) the electronics shuts the drive down. That is my guess anyway.

I've looked at the current draw when it is operating. It's somewhere in the vicinity of 2 amps, which seems reasonable. The sound it makes is akin to an on/off noise that seems like something is barely making contact, to the point where it ultimately stops and the "drivestop" message appears.

Next comes the hard part - twisting myself back into its mounting and removing the unit. At 6'1" and 200lbs, I may have to solicit someone with a smaller body to perform the task. (One time I got myself so hopelessy "caught", hanging from my ankles and suspended head-first in the engine compartment, I though I was going to have to have a line tied around my ankles and be winched out off of the boom.)

[Talbot]

I suspect that the new linear drive is slightly more powerful, but you could always go for the next size up if you are getting a replacement.

As to open heart surgery - if it doesnt perform at the moment, what do you have to lose.

I understand that these motors are not too fond of salt water, so if your compartment containing this motor does get the occasional salty bath, that may be the problem.

[DeepFrz]

Kevin;
If you do take it apart and clean it, how about posting some pictures and your observations.

I just love Raymarines statement "there are no user serviceable parts in any Raymarine system". For seagoing equipment, does that make sense to anyone?

Of course you could always build yourself a hydraulic drive.

Phil.

[Raven]

Originally Posted by DeepFrz

Kevin;
If you do take it apart and clean it, how about posting some pictures and your observations.

I'll try to have the camera handy.

Originally Posted by DeepFrz

I just love Raymarines statement "there are no user serviceable parts in any Raymarine system". For seagoing equipment, does that make sense to anyone?

Sounds like a good selling point for wind-vane steering systems.

[S/V Elusive]

I have the older version of that linear drive unit (didn't have to upgrade when I replaced all the other components of the system). My drive is very quiet and seems to handle the boat well - except when downwind with quartering seas - the boat skews around so much that it exceeds the 'out of course' range and drops out to Standby. I suspect that the 'smarter' course computer 'learns' and eventually is able to handle that?

I've found RayMarine CS to be spotty - fortunately, I found one of their systems guy at a boat show, got his card and through him got the name and number of their chief technician at the factory. They have refurbished units that they sell at a substantial discount. The way *I* tapped into it was they told me to send in the whole system and they will check it out and then let me know what they can do, and the cost to do it. I was a bit unsure of this approach, but it turned out okay. The long and the short of it ... I would contact them (regular CS should work for that) and send the unit in - during the course of their evaluation, they may accidentally fix it or not, but the cost of a refurbished unit may convince you to upgrade.

Good luck - and keep us informed!

[Talbot]

I have done exactly the same. First time they fixed it within the limit I had set. The second time they explained exactly what the problem was, and why they were unable to fix that unit, and offered "trade-in" for a replacement system. - the old one was 20 years old so didnt owe me anything.


The newest Raymarine systems can have an optional rate gyro fitted (the G in S(1)G). This senses the speed of course alteration, and adjusts the steering to compensate.

[jstevens]

Kevin,
As one who has gone through a series of Raymarine autopilot problems and who is over 6'1" and is not a narrow body, I "feel your pain".

First of all when you say it doesn't work please describe the symptoms. Does it work for a period of time and then drop into standby or does it just refuse to go into Auto, so something else.

Without any further information I recomend you check all of your electrical connections between the drive unit and the course computer and the comuter to battery. Corrosion or loose connections can increase the electrical load to the drive unit and shut down the computer.

I don't believe the drive unit is easily user serviced, but the drive motor can be replaced. I just had a technician replace a presumably more expensive Type 2 motor in Gibraltar for about $250. I might have done it myself, but then I would have to deal with getting the motor from Raymarine, customs, VAT, etc. Your are only a few miles from the Raymarine factory in NH, so that shouldn't be an issue for you.
If the motor doesn't fix the problem i'm afraid it just gets real expensive after that - a new computer.
That was my final result.
John

[Tom51]

Kevin, did you resolve your autopilot problems.....I have identical situation and was advised by technicien as to what was wrong.

[Raven]

Rain, rain, rain here in the northeast. Brightwork is behind schedule along with every other project. Haven't pulled the linear drive out yet . . . . . . but hope to post some photos of the unit with its likely gummed up brushes once I get caught up and open it up.