Crazy Autohelm wind sensor

[SvenglishTommy]

My autohelm ST50 wind instrument seems to be going insane. Ever since I bought the boat it's never been right. Original it was 180 degrees out, and everytime I try to calibrate it, it only holds out for a few minutes before it drifts randomly around the place. The wind speed seems to be ok, but I have no idea why the direction is so messed up.

I think the sensor was replaced just before I bought the boat, so has probably never been right.

Any ideas?

 

[earlybird]

Might be worth confirming that the wind-vane is firmly attached to its shaft and not slipping round. It's fixed by a very small socket-head grub screw IIRC.
Perhaps not very likely, since it could well have blown off by now, but at least doesn't cost anything to check.

 

[KellysEye]

We had the same problem last week with a Raymarine ST40, Earlybird has the solution above. The socket head grub screw has probably rattled out. We epoxy glued the shaft back in to ensure it doesn't happen again.

 

[SvenglishTommy]

Thanks guys, is there a way of identifying if this is the problem without going up the mast. I need to go up there at some point anyway, but am doing all I can to avoid it

 

[maby]

You haven't accidently switched it to the "Close Hauled" scale, have you? I came very close to ripping ours off the top of the mast with similar symptoms till I noticed the "CH" label on the display (Tacktick, not ST50 - but most wind displays have similar functionality).

 

[nigelmercier]

My autohelm ST50 wind instrument ...

I'm confused. Is this your autopilot, or your wind instrument? As far as I know Raymarine didn't make either in the ST50 range.

 

[cliff]

I'm confused. Is this your autopilot, or your wind instrument? As far as I know Raymarine didn't make either in the ST50 range.

Duh? Raymarine ST50 Wind Instrument Service kit