Raymarine S1G autopilot help please

nimbusgb

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My S1G autopilot has the usual fluxgate compass attached. Went haywire yesterday swinging all over the place often more than 90 deg off. Tinkered with it, recalibrated and new seatrial. Aligned heading etc. This morning the heading is 20 degrees off. The blasted thing has only about 200 hours on it!

Question: Can I do away with the Raymarine junk compass and feed an aftermarket NMEA compass in to the S1G instead? Will the S1G see and utilise the NMEA stream instead?
 
Yes you can but you do not want to. If you really have the S1G and not an S1 then you want to use the Gyro - allows the auto-learn, better sea-keeping and reduces the power consumption.

I would do try and work out what the problem is - possibly you have a faulty course computer? regardless there should also be an external compass as well as the internal Gyro.
 
Yes you can but you do not want to. If you really have the S1G and not an S1 then you want to use the Gyro - allows the auto-learn, better sea-keeping and reduces the power consumption.

I would do try and work out what the problem is - possibly you have a faulty course computer? regardless there should also be an external compass as well as the internal Gyro.

Gyro is probably internal in the course computer casing. So dumping the external fluxgate and replacing with 3rd party NMEA compass might work without affecting gyro.
 
The pilot has apparently worked fine for a couple of seasons ( holds course better than I do! ) and on this particular run ( Sivota to Gouvia perhaps 4 hours ) tracked just fine for several hours and then all of a sardine it changed course 90 degrees to port ..... violently, then it decided that there was something amiss and changed course starboard. I am watching the e-80 and see the red heading line diverge from the gps track line to starboard 40, 50 then nearly 120 degrees. The binnacle compass and hand bearing agree, the fluxgate input is way off. I don't stop the engine ( I suspected voltage problems ) but do come to idle and out of gear. I go below strip the compass and put it back together ( there's not much to be seen inside) then go back topsides and do a full seatrial re calibrate of the system ( sailing round in circles off Corfu! ) during which all seems OK again but I don't trust the damn thing further than I can see it! ( and that's not far ! ) A dodgy autopilot when single handed is a little worrying!

I do have the S1G. External fluxgate compass and the internal gyro.

The quandry of course it that it works so damned well when it does work!
 
The pilot has apparently worked fine for a couple of seasons ( holds course better than I do! ) and on this particular run ( Sivota to Gouvia perhaps 4 hours ) tracked just fine for several hours and then all of a sardine it changed course 90 degrees to port ..... violently, then it decided that there was something amiss and changed course starboard. I am watching the e-80 and see the red heading line diverge from the gps track line to starboard 40, 50 then nearly 120 degrees. The binnacle compass and hand bearing agree, the fluxgate input is way off. I don't stop the engine ( I suspected voltage problems ) but do come to idle and out of gear. I go below strip the compass and put it back together ( there's not much to be seen inside) then go back topsides and do a full seatrial re calibrate of the system ( sailing round in circles off Corfu! ) during which all seems OK again but I don't trust the damn thing further than I can see it! ( and that's not far ! ) A dodgy autopilot when single handed is a little worrying!

I do have the S1G. External fluxgate compass and the internal gyro.

The quandry of course it that it works so damned well when it does work!

I assume Sivota on Levkas. If so and you went close in to Gaios there appears to be some sort of magnetic anomaly thereabouts which has had my compass going all over the place before.
 
I am watching the e-80 and see the red heading line diverge from the gps track line to starboard 40, 50 then nearly 120 degrees.

I had the same issue. Could see the red line on C80 doing full 360 degree rotations.
I originally replaced the fluxgate compass internals but had the same issue.
In desperation I replaced the replacement fluxgate in its entirety and all was well after that.
If you think the problem is connected to the gyro heading sensor you can easily unplug it from the internals of the S1G. When you take the cover off it's the only two pin plug on the circuit boards back.
 
My S1G autopilot has the usual fluxgate compass attached. Went haywire yesterday swinging all over the place often more than 90 deg off. Tinkered with it, recalibrated and new seatrial. Aligned heading etc. This morning the heading is 20 degrees off. The blasted thing has only about 200 hours on it!

Question: Can I do away with the Raymarine junk compass and feed an aftermarket NMEA compass in to the S1G instead? Will the S1G see and utilise the NMEA stream instead?

NASA do a nmea fluxgate compass at a reasonable price.
 
If you haven't already, check the Fluxgate wiring to the Course computer for broken / loose wires. Also check the cable run to make sure it is undamaged.

I found this via google. Simple and worth a try: https://raymarine.custhelp.com/app/answers/detail/a_id/134/~/advanced-compass-troubleshooting

Thanks but that site has been disabled!

Having stripped and rewired the compass unit it appears to be working OK ...... for now.

I'll see how it holds up but a bit worried since I sail single handed frequently and not knowing if it's going to throw a quick 90 or 180 degree turn is a pain!

I still don't know if the S1G will work with an external NMEA compass though :)
 
Yes, the site appears to be down for maintenance currently.

I found this in the Smart Pilot series Commissioning Guide regarding NMEA compasses:

Connecting SeaTalk or NMEA compasses
You can connect SeaTalk or NMEA compasses to the SmartPilot computer, either
to replace the fluxgate compass or provide supplementary compass signals.
When you connect more than one compass to the autopilot system, the computer
processes their signals in this order of priority:
1. Fluxgate compass
2. NMEA compass
3. SeaTalk compass
This means that if you want to use a NMEA compass as the primary compass, you
need to disconnect the fluxgate compass.
To connect a SeaTalk or NMEA compass to the autopilot system:
• NMEA compass: connect it to a NMEA input on the computer
• SeaTalk compass: connect it to the SeaTalk bus or the SeaTalk terminals
 
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