Autopilot steering off course

[V-Dog]

1st post, please be gentle.

Currently moving a new to me boat down the Chesapeake; boat has Raymarine e95 MFD and p70 Pilot Controller. When I engage autopilot the boat turns to hard to starboard ~30 degrees from current heading but autopilot display still shows desired heading. When I press standby on autopilot the true course heading will then display. I deleted any GOTO waypoints and old routes. Only current work-around is tried and true hand steering.

Is there an easy button that I’m overlooking?

Thanks,
Andrew

[Dsanduril]

Andrew, welcome to CF. And to Raymarine APs. Does the AP have a rudder reference sensor? This will show up on the P70 as a red/green bar across the top (with default display settings). If so, when engaging the AP it will always turn the rudder so that the rudder angle is zero. If you have a bit of weather helm (sailing) or the rudder sensor angle is just off then you get a big turn. Eventually it will work out that zero rudder angles doesn’t mean you go straight, but it can take a while.

We have a similar setup and twin engines, but usually only use one. So, when motoring we always have about 5 degrees rudder angle, can be to port or to starboard depending on which engine is running. The Ray always turns to zero rudder angle when engaged. We’ve learned not to engage in narrow places so it has time to work things out. Option B is to disconnect the rudder sensor, if it doesn’t know where the rudder is it can’t turn it to zero. The guys who programmed these would fail Automation 101.

[Captain Bill]

Have you tried redoing the calibration procedures? Some software updates require you to recalibrate after the update is applied.

[V-Dog]

Hi Dsandural,

The autopilot does indeed have the rudder reference sensor. I tried engaging AP when at rudder sensor was at zero but it still pulls to starboard.

Option B may be on tonights agenda at our next anchorage.

Andrew

[V-Dog]

Hi Captain Bill,

Thank you for responding. I have not recalibrated. It looks like my honeydew list is getting longer.

Thanks,
Andrew

[Dsanduril]

Well, the only other thing I have up my sleeve is track mode, in track mode the Ray AP (at least the SPX series) will turn exactly 30 degrees if the XTE is > 0.01 nm until it gets XTE down to 0.0. This is so bad that it makes track mode almost useless. Doesn't sound like you're using track mode, but when I see 30 degrees in reference to a Ray AP, well, might as well mention it. I've had a bit of conversation with Ray about both of these "features" and they are pretty unapologetic, while acknowledging that they do exist.

Before disconnecting the rudder sensor I'd probably run through the calibration as Bill suggests. It's pretty simple and may sort out the problems.

[V-Dog]

Thank you for your help Dsanduril. At least I don’t feel like a complete idiot now.

I will run the recalibration tonight. If that doesn’t work I’ll give Raymarine a call.

Thanks,
Andrew

[Dsanduril]

If you do speak with Ray they'll want to know what course computer you have. The P70 and the E95 are the front end, but somewhere buried in the boat is the black box computer and heading sensor. I can't remember if there's a way to get that information from the P70/E95.

And one last thing to check, find the heading sensor and if it is a fluxgate compass make sure no one has placed some big chunk of ferrous metal nearby (or worse, one leg of a DC electrical circuit).

[V-Dog]

Will do, thank you.

[edsailing]

Originally Posted by V-Dog

Will do, thank you.

Raymarine APs will generally try to put you on the track line rather than the course to destination. If you have crosstrack error it will do a hard course alteration to get you 'back on track'.

[Nicholson58]

Originally Posted by Dsanduril

If you do speak with Ray they'll want to know what course computer you have. The P70 and the E95 are the front end, but somewhere buried in the boat is the black box computer and heading sensor. I can't remember if there's a way to get that information from the P70/E95.

And one last thing to check, find the heading sensor and if it is a fluxgate compass make sure no one has placed some big chunk of ferrous metal nearby (or worse, one leg of a DC electrical circuit).

+1 on the flux gate. I also wondered if the flag gate might be faulty.

[Stu Jackson]

Welcome, good first question and well presented, which does its usual magic of getting fine and concise assistance.


It's pretty amazing that these days they can still kludge a simple algorithm, agree with input that it should be corrected or at least provide a work-around the fault (which should at the very least be an option, right?), and still do nothing for a product that to keep up cries for and already has a way to update the software.


But most of it works and folks have them and like them, with good reason.


Good luck, hope to see more of you here.

[V-Dog]

Thank you Ed and Nicholson58 for your replies, and thank you Stu for the kind welcome.

The collective knowledge on this forum is amazing. I was just about to break out my trusty hammer to lightly coerce the autopilot into submission before reaching out. I’m still sorting the issue out but I am sure to be back to pick your brains on future problems.

Andrew

[sailing_gal]

Years ago with an older RM autopilot, I ran into a situation where the AP would not track. It turned out to be the computer, which I tested with the assistance of the RM help desk. At the time that it failed, I was in the Bahamas and had to get back to the U.S. I found that, while the AP would not track, I could get it to sail off the wind at a wind angle. Not helpful if you are motoring, but at least it saved me some hand steering when there was wind.

[Smokeys Kitchen]

That was my thought. If there are selections, make sure it is in compass mode and not wind or track modes so it steers to the compass Heading displayed