my ST6001+ steers 30° to starboard when I hit Auto

[uncle stinkybob]

Originally Posted by electronicmarin

the rudder is on the center on the display when you are going strait? the compass alignament procedure gave you less than 7 degrees compensation?
things that people seems not to undarstaind that betwwen the magnetic (filed with liquid) compass, the autopilot compass and cog (from the gps) you have 3 different things and that's normal, is basic navigation, the magnetic compass is without deviation, the autopilot one is in somme way compensating for that deviation (hence a different value) and the gps compass value cog (course over ground) is yet another value that's the true heading of the boat...
My advice: reset again the autopilot and with no modifications (just put the correct rudder type on st6001) see if the autopilot is keeping the heading when you press auto, then will see from there...

Thank you for this post. I have been pissed at the difference's in my reading's between those three ever since I installed my Raymarine autopilot.
The autopilot itself has operated flawlessly though.

[CampDavid]

They will never all match perfectly

St6000+ and compass should be close be sure tbe st60 00 is not set to heading

Sent from my SGH-I337M using Cruisers Sailing Forum mobile app

[allatsea99]

This is probably of no help as I'm not dealing with an ST600. I had exactly the same problem but may be for different reasons - refitted the quadrant and upset my rudder transducer (tells location of rudder).. my system is a Coursemaster though. There was a procedure for switching system on and off and temporarily cutting power to the drive motor, essentially telling the motor it was OK - I was on the right heading no need to move me 30deg. All fixed now.

[Seighlor]

About a year ago I installed a new pilot. For months I suffered with a twenty degree turn to starboard every time the pilot was engaged. Within less than a minute my boat would return to the course that had been input. This was not a terrible thing in open ocean waters but it went beyond the nuisance factor while within the confines of a marked channel. I called Raymarine and was referred to a Mr. Lee. Mr. Lee was terrific. He had me go through a number of procedures while secured in my slip. I'm unable to recall the programming factors we went through but my problem was fully resolved. My suggestion: call Raymarine.

[ramblinrod]

Originally Posted by Brann

Here are a few precisions :
- the control unit version is 15 and the course computer version is ver 227
- my course computer is a raymarine smartpilot s3G ast
- my rudder is centered when I'm going straight


The autopilot worked flawlessly for thousands miles. Two weeks ago I connected it to my tridata to enable the wind mode. One week later (causality or correlation, I don't know), I noticed my compass was off gainst the GPS COG. This is not unusual in Brittany where I'm sailing because of very strong tidal currents, so I don't know exactly when it happened.

Anyway, I followed the calibration process (2 circles at 2 knots). I can't remember the compensation. The sharp turns configuration thing is for gyroscopic versions only, which I don't think I have. I think the pilot was behaving correctly then (but I'm not sure as I might have used my secondary auto pilot to go back to the harbour, I can't remember).

Next time I left the harbour, I had the very strange behavior I described.

To ElectronicMarin, I think I understand the difference between a true heading, a magnetic heading, and a course over ground. In my case I know my autopilot compass is reasonably accurate, as I compared it against other compasses, and even against a known alignement on ground. It is definitely not 30° off. I'll retry calibrating the raymarine to get the compensation it finds as I understand this is a useful debugging information.
When you suggest a reset, are you talking about a compass calibration reset or about a full factory reset ?

Thanks a lot

When trouble-shooting any system, always ask yourself, "What has changed, since it last worked properly". If you can identify anything, start with that.

In this case, the most significant change to a perfectly working system was the connection of the tridata, and then it started working strange.

Step 1:

Disconnect the tridata and see if operation reverts back to the way it was.

If yes, it is likely related to the passing of information the autopilot did not previously have access too. (Is it now compensating for leeway or current drift? )

If no, is it an EMI issue, were proper ferrites installed?

Certified Raymarine Installer / Service Provider

[Brann]

Hi again,
Thank you all for your suggestions. I just crossed the Biscay and I'm grateful my Raymarine was here to steer through the passage.

I've seen than rebooting the Raymarine system completely (ie shutting down the electricity) changes the problem. After one restart I just had a 5° angle, and after another one I had 2°. I didn't dare restart again as I was in a "don't risk breaking the thing you need most right now" mindset.

I wonder whether the whole thing might be linked to the rudder angle when the pilot is started. I'll test the theory and I'll keep you posted.

Also, I contacted raymarine when I posted here, I'm still waiting for a reply.
Cheers
Brann