Compass alignment on Raymarine C80 et al

[WayneS]

Looking for help guys.

We have a C80 plotter with a GPS, Radar, Smart compass, Gyro, 4000Mk II autohelm, ST60 Wind and ST60 Depth/Log.

All was fine and dandy last year but this year we are suffering major compass alignment issues. The normal steering compass is fine but the heading on the C80 can be as much as 90 degrees out.

We have gone through the Linearise process and aligned the compass, both processes seem to work properly.

When we aligned the compass on Sunday we were almost due north and it looked fine, till we turned around and it went out of alignment again. Turning back north it came back into alignment.

Nothing was added or moved on the boat between last year and now and there are no metal objects anywhere near the compass sensor.

I have spoken to Raymarine and they say that we must get an engineer our which I will do, but does anyone have any suggestions?

 

[CSFenwick]

Most obvious is that something metallic is near your fluxgate. I know you said there wasn't but I was getting some dodgy headings (not as bad as yours to be fair) and it turned out that my wife had put a storage rack (the type that you hang in a wardrobe and they concertina up) in the wardrobe in our cabin which also houses the fluxgate. The thing is made of fabric so I didn't suspect it at all. Then I moved it and watched the orientation of the boat on the display and sure enough it was affecting the fluxgate. Turns out that there are small metal bars in it. You can hardly feel them through the material but it was enough to affect the compass. So, the first thing is to move everything that’s within 50 cm of the fluxgate (including behind the wall it's on!) away and see if things improve. If not then next step is to take the fluxgate out and send it to Raymarine for checking. You should also send your course computer as in my experience that’s a bigger source of errors than the fluxgate. If you pay a bit extra Raymarine will look at it straight away so you should have it back reasonably quickly.

 

[saltwater_gypsy]

Have you done the sailing slowly in a circle thing to recalibrate the fluxgate compass??

 

[WayneS]

Thanks Orenda

I did remove things that that I though would affect it but your experience suggests I should remove everything and try again.

 

[WayneS]

Saltwater_gypsey, can confirm that I did that.

Cheers

Wayne

 

[TonyS]

I had a misalognment problem last year. You can read about it here:-
http://www.ybw.com/forums/showflat.php/Cat/0/Number/1528897/page/0/fpart/1/vc/1
May be some help.

 

[hairbox]

Access the advanced dealer calibration and change the VESSEL TYPE to an alternative setting (i.e. from DISPLACE to PLANING), press and hold the STANDBY key to save settings... power cycle the system then return to the dealer calibration and change back to the original VESSEL TYPE; this will instigate a reset and hopefully, resume correct compass readings

hope this helps
from Ray Eng