Autopilot Problems

[RDL]

Yes, thats correct Andy, Autopilot will stear a straight course when used on its own, but its compass direction will have drifted, and does not agree with main compass or COG (by miles)

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[andyball]

So when it steers a straight course used on it's own....even though the compass direction is miles out....what is it trying to steer to? not a heading , 'cos that's miles out...so ?.

Only wondered if somehow the autopilot/fluxgate was set to receive nmea/seatalk heading, rather than send it & if problem only ocurred when nmea/seatalk from ap was plugged into the gps etc....perhaps try with the gps unplugged?-

Just that you mentioned it all worked ok separately....but how can the a/p be steering a straight course if the heading from the fluxgate keeps changing?



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[RDL]

The compass heading did not drift that quickly as to affect straight line course keeping accuracy over a couple of miles when using A/P only. Autopilot test only was done to test straight line accuracy after it could not hold a straight line cource when tracking a waypoint. Going from Cowes to Chi, must have re aligned the compass 4 times.

Hey, it may be a loose wire when I am able to get down there and play with it further. It's really frustrating being so far away, and not being able to pop down in the evening.

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[andyball]

hopefully it will be an easy fix.

afaik, the fluxgate/smartheading bit can be independent of the ap (used for clever radar display), so likely this at fault?, shd be possible to unplug the ap & display heading on the main screen (got to be an option somewhere?) + watch to see it change (or not). Then at least it's only one item to remove.



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[Piers]

One point to check is that nothing is anywhere near the fluxgate that might influence it. A friend of mine used to put his laptop near mine, and that's when my heading problems started!

However, try calling Dave Welcome of Raymarine. He's their autopilot engineer guru and has helped countless people from the forum. 02392 693 611 extension 1614.

<hr width=100% size=1>Piers du Pré
http://www.dupre.co.uk

 

[RDL]

Just had a thought, Last weekend heating had packed up so I brought down a convection heater. While not in use I stowed it on the floor between the two bunks in in the aft cabin. The fluxgate compass is mounted just underneath in the stoewage compartment under one of the bunks. Now carn't remember if it started playing up before or after. I will give Dave Welcome a call. Thanks

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[Piers]

Thanks for the feedback. You need a large clear area around the fluxgate. Operationally it's easy to forget!

You will find Dave a great help. He's been developing autopilot software for years. Do let him know it was me that suggested giving him a call.

Let me know the outcome when all is working well. Have fun.

<hr width=100% size=1>Piers du Pré
http://www.dupre.co.uk