Autopilot Problems

[RDL]

I have recently installted a new Raymarine C80 plotter and a 6001 Autopilot system with built in Gyro. All items wotk fine on there own, but the Autopilot goes wildly off track when following a waypoint from the plotter. In addition the autopilots compass direction gradually loses its alignment with COG. This loss of alignment is probably the reason for its poor course keeping. Its been calibrated correctly on sea trial, and Raymarine say it may be a fluxgate problem or the course computer itself and suggested bringing the whole unit into them.

Before I rip the whole installation out and take it to Portsmouth, which is not easy when you live 170 miles away from the boat, has anyone else had similar problems with autopilots.

Thanks, Rob




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[Mike21]

Be worth checking that autopilot is set for type of boat, ie planing hull, cruising speed etc. If I remember correctly, Raymarine manual says something about fitting ferrites to cables to stop noise, maybe possible noise pickup causing problem

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[RDL]

Yes, all settings are correct for type of boat and speed, and yes you are right about ferrites, don't know if I have any.

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[djefabs]

Hi Rob
Did Raymarine give you an answer re. their equipment switching off just inshore of the Bar Beacon? Perhaps its a call to mulder & scully?

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[RDL]

No, not a clue, it will need some serious detective work. Just a thought, how does it know when your comming back in to Chi, doesn't do it on yhe why out - spooky hey....!

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[sailorman]

wot about "linerising" the compass.
going around in circles slowly as per the manual

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[sailorman]

wot about "linerising" the compass.
going around in circles slowly as per the manual

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[RDL]

Yep, done that - twice actually. First time 2 Deg variation, 2nd time 8 Deg Variation.

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[amf]

I think I have similar problem. Have a Garmin connected to a Raymarine 6001 autopilot with Gyro (installed about a month ago). Went through the dealer setup and all seemed to function OK including tracking a waypoint. Over a series of trips I can no longer track a waypoint - haven't tried recalibrating yet but the Raymarine compass heading seems to have drifted (or the calibration settings have been lost).

If a go to track mode it keeps coming up with "next waypoint" every 10 seconds or so. Going to auto mode to track a set heading and using the +10 -10 etc works fine.

I am going to try recalibrating next time I'm out but failing that, will be giving Raymarine a call.

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[RDL]

Andrew,

Go into sea trial calibration and re allign the compass heading, you can do that by simply pressing auto on that calibration page, the compass heading will than be taken from the COG from your Garmin. I had to do this several times in one trip on Sunday, as it kept drifting.

Oh well, looks like I will have to take the whole unit out and take it to Raymarine.

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[steverow]

How wildly off course is it??

I doubt very much whether it is an electronic failure.
You could whip this out send it back to RayM and still have the same problem at the end of the day.
Fluxgates and autopilots are things that very much need attention in situ to get to the root of the problem, and particularly with them hooked up to the other bits of tackle that they are working with.

Anyway I'm probably teaching you to suck eggs but here are the things it could be.

1, "swing" the compass for Dev by going round in a 2 or 3 knot circle very slowly.

2, Align the compass heading by checking with a known bearing (or another vessels proven aligned compass).

3, Make sure all components in the NMEA or Seatalk system are working to either Magnetic or true but not a mixture...for a Garmin to work in true usually you have to set Variation to zero.

4, Finally check the siting of the fluxgate and that there is nothing interfering with it. Even ad..hoc items placed near it on the floor (if it is low down in the boat as it should be) can interfere with it as I know from "bitter" experience.
(Not all beer cans are pure aluminium...!!)
In my case a small plate heater about a meter away was also causing a problem.

5, If all else fails call in a decent marine electronics guy to sort it, but it will be best diagnosed in-situ, at least in the first instance.

Steve.


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[pissativlypossed]

Had a very similar problem with the installation on my boat upon delivery, the dealer was unable to identify a problem, and he bought in a local based electronics engineer, it transpired that the boat builders (French) had taken up some slack in the cable conecting the gyro compass to the reciever by wrapping it around the compass.After re-routing the cable and recalibrating deviation is less then 2 deg.

<hr width=100% size=1>"Open Another Bottle"

 

[RDL]

Steve,

Thanks for the reply. All the things that you mention I have done correctly, ie, swinging the compass in large circles at 2 kts, and aligning the compass. As I mentioned earlier the algined compass heading on the A/P drifts, and possibly this is why it will not maintain the Waypoint Track. It does seem to suggest a Fluxgate problem. I do have the old Fluxgate, so maybe re-install that one to discount failure of the new.

I do agree that the best option is to try and fix in situ rather than rip the whole thing out.

Rob

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[jimg]

Where is the boat moored? Surely a local Raymarine agent can look at it under warranty?

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[RDL]

The dealer that supplied the equiment did not install. May get local RM engineer to have a quick look.

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[Oldhand]

I presume you go so fast that you expect the autopilot compass and COG to agree without any influence from tidal current?

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[Wiggo]

Fraid so, mate. Tide or wind having an effect is a sure sign something has broken...

<hr width=100% size=1><A target="_blank" HREF=http://homepage.ntlworld.com/graham.wignall/boats/eulimene600x800.jpg>The old and the new</A>

 

[Moose]

I have problems with my Echosounder and GPS just south of the Bar, apparantly it is something to do with underwater cables to the Bar for their weatherstation, I cant see that this would cause it but who am I to question!

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[RDL]

I'm not talking about a few degrees difference here, as one would expect at 24 kts allowing for tides, the difference is 120 degrees.

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[andyball]

You say all items work fine on their own ....including the autopilot?.... or does the autopilot's compass direction go miles off even w/o connection to the gps?.

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