Raymarine ST1000+ and External Compass

[UKDEN]

Has anyone used an external fluxgate compass with a ST1000+ tiller pilot?

My St1000+ works fine when I am sailing, but if I start the outboard it hunts constantly. The rotating flywheel with magnet certainly affects the built in fluxgate on the Raymarine unit.

Problem is the outboard is permanently sited in a well and the tiller is directly over it.

I am thinking about an external fluxgate compass.

Anyone any experience of using one with a ST1000+?

Thanks in anticipation

 

[nigelmercier]

I don't have the same model, but assuming there is an external fluxgate option, there should be no problems. Mount it as central and as close to WL as possible, and put a warning sticker on the door if mounted in a locker; a set of headphones can really confuse them!

 

[awol]

I have an Autohelm steering compass display with separate fluxgate compass connected to a ST2000+ via Seatalk. The ST2000+ display mirrors the compass display and waving a magnet over the autohelm doesn't cause any change so I guess it works ok.

 

[wooslehunter]

I was given an old Raymarine fluxgate & display a while ago which I haven't yet fitted. So, I haven't tried it. However, Raymarine told me that the tillerpilot will use the external fluxgate if it's present on the Seatalk bus rather than its own internal compass.

However, before investing in an external compass, you may like to look at confirming the source of the interference. It could be caused by noise that the motor is putting onto the power lines. Check out two things.

1. Power your tiller pilot from a temporary battery. If the problems go away, then you may find that you have noise on the power lines from the engine.

2. Power the tiller pilot from the normal supply but move it physically away from the engine. You will be able to push the Auto button & if you move the tiller manually & change course, the pilot should respond. Alternatively lash the tiller to keep the course & then move the pilot. If it works fine, the the interference is via the ether rather than conducted via the power lines.

These tests won't be conclusive but will tell you something before you spend on an external compass.

Having said all of this though. It may simply be the way you have the pilot set up. Boats often have a different dynamic response under motor or sail. They can often be a little more sluggish under sail because the sails & wind strength have a major effect on the course - the cause of waether & lee helm for instance. Under motor only, the rudder is the main factor assuming a fairly flat sea. So, if you have the pilot set for nice tight control under sail, it may be a little too sensitive under motor which can cause the control loop to hunt. So to test this, start up the motor but leave it in neutral & sail. If the pilot starts hunting, then it's interference. If it makes no difference, then you'll have to play with the rudder gain & damping settings in the setup menu.

 

[UKDEN]

I believe Seatalk is going to be my only option.

Anyone any idea what the minimum kit is that I can get away with?

I do not need a compass display, I have a perfectly good conventional compass.

 

[UKDEN]

However, before investing in an external compass, you may like to look at weather the interference is caused by noise that the motor is putting onto the power lines.

With the battery disconnected from the engine (removed charging plug on outboard) the interference is still there.

Also, with the engine stopped, if I slowly turn the flywheel by hand, I get large swings on the heading readout on the ST1000+.

I am pretty certain it is magnetic interference.

 

[shaunksb]

My St1000+ works fine when I am sailing, but if I start the outboard it hunts constantly.

I have exactly the same problem, I think.

I say I think because the previous owner of my new (to me) boat described that symptom exactlty. I thought it may be that it was just broken as i'd not heard of that before and presumed that with lots of boats having outboards in wells Raymarine would have fitted some kind of suppression.

Does anyone have any idea how you would actually wire the compass to the tillerpilot as I don't pariculary want a compass display?



_______________________

 

[Kylora]

I can't answer the ? but can confirm that the ST1000+ is very sensitive to external magnets - much more sensitive than a bulkhead compass.

I could never get a satisfactory deviation on mine and eventually realised that it was being effected by the seasearcher magnet (fitted with the bar) which was stored about 1.5M away.

I also read a post on here where the OP felt that his TP compass was being badly effected by the vibration from the engine.

Ash

 

[awol]

All the data I have gives a 7 wire connection for the fluxgate compass, of which 2 are NMEA, for connection to a compatible display, course computer, etc. The ST1000+ accepts course data via NMEA. What I can't find though is what NMEA words are involved.
My ST2000+ set-up accepts heading, wind direction and boat speed via Seatalk with GPS track, WPT distance, Xtrack error via NMEA.
Good luck!

 

[UKDEN]

1. Power your tiller pilot from a temporary battery. If the problems go away, then you may find that you have noise on the power lines from the engine.

2. Power the tiller pilot from the normal supply but move it physically away from the engine. You will be able to push the Auto button & if you move the tiller manually & change course, the pilot should respond. Alternatively lash the tiller to keep the course & then move the pilot. If it works fine, the the interference is via the ether rather than conducted via the power lines.

.

I am fairly certain it is the rotating magnet in the flywheel which is causing the problem.

I have tried disconecting the charging line from the engine (simple plug on outboard), it makes no difference.

If I rotate the flywheel slowly by hand, I get large deviations on the ST1000+ heading readout.

PS. this is the second time I have tried to post this message, the previous attempt (over a day ago) appears to have got lost!