Snaking Raymarine autopilot

Just bought a '02 Mainship 30 with 2017 A series raymarine hooked with 2017 EVO autopilot. works ok at low speed but with any kind of "seaway"j, like 1 foot chop it wanders 5-10 degrees with noticeable snake wake. it is set on cruise mode and is worse on performance mode
I had a Raymarine tech guy come out and redo all the settings. He notice that the installation does not have a mechanical rudder position indicator but said it doesnt need one with new Raymarine setup.

He wants to sell me a new Garmin autopilot.
What to do?
would a manual rudder indicator help?
is it something about the mainship instability?
get a new tech guy?

bruce adornato
sausalito california

adornato said:

Just bought a '02 Mainship 30 with 2017 A series raymarine hooked with 2017 EVO autopilot. works ok at low speed but with any kind of "seaway"j, like 1 foot chop it wanders 5-10 degrees with noticeable snake wake. it is set on cruise mode and is worse on performance mode
I had a Raymarine tech guy come out and redo all the settings. He notice that the installation does not have a mechanical rudder position indicator but said it doesnt need one with new Raymarine setup.

He wants to sell me a new Garmin autopilot.
What to do?
would a manual rudder indicator help?
is it something about the mainship instability?
get a new tech guy?

bruce adornato
sausalito california

Click to expand...

Sounds like a setting thing to me, such as "Yaw" setting to loose. If this tech couldn't adjust the settings and wants to sell you another AP, I would suggest getting another tech to look at.

Does this happen at all points of sail or just going downwind. If downwind then it is probably due to seas pushing the stern around. Common on many trawlers. Don't know about that model, does it come with a gyro feature or only fluxgate compass heading. On my Mainship 34T I added the gyro feature, at the time it was a black box add on and that tamed the S turns nicely.


Maybe a rudder sensor would help. It provides positive data to the autopilot's algorithm of where the rudder is rather than infering it from past movements.


If the RAYMARINE tech guy wanted to sell you a new Garmin autopilot, he clearly wasn't trying to fix your problem. I would find someone else.


David

I believe all the Raymarine EVO pilots are gyro corrected. I've not had one without the rudder sensor, but with one I get no yawing upwind or down on either my trawler or my sailboat. I'd tweak the settings (there are many in the advanced section) and perhaps add the rudder sensor.

What is the exact model of autopilot course computer?

First off, which Evo autopilot is it? I would hope not the EV100 and type .5 pump. The EV150 with a type 1 pump would be the minimum autopilot for your boat.
Secondly, yes , a rudder feedback transducer would help immensely but it's not imperative to make it steer satisfactorily.
What do you mean by he redid the settings? He should've checked for and adjusted the hardover to hardover time in the pump settings. That would make the biggest difference in the boats wandering since it doesn't have a feedback.

I am not an expert on autopilots -- or anything for that matter.

I will note, however, that I chartered a Mainship from Club Nautique in Sausalito (where you appear to be located) on a couple of occasions and found it VERY difficult to maintain a straight course in manual steering with a moderate chop. My assumption was that the relatively light weight of the boat and the shallow draft made for a hard-to-maintain course.

Good luck in getting that figured out. I hope there's an easy fix with the AP.

I installed an Evolution AP a couple years ago. Night-and-day compared to the previous Raymarine AP I had (circa 2006, but I am convinced that unit had an underlying hardware problem I never located). The new Evo is fantastic in comparison. No snaking.

I do have a rudder sensor. (One comes with the AP, but I simply reused the one from my old AP rather than run new cables).

The Evo APs have very few setting compared to previous generations. Basically run it through the learning process and that's that. I don't know that there are many settings to "redo", and coupled with the fact he wanted to sell you a new AP suggests he is not someone I would count on for help here.

Ask Raymarine tech support: Raymarine forum

The Raymarine forum is very good at solving problems.

In the autopilot drive settings you can set: Rudder damping, rudder limit, rudder offset, response level, and hard over time. The rudder damping and response level are the most likely ones to play with, assuming hard over time is set correctly.

You didn't get a Raymarine tech. He was a Garmin tech. Settings need to be tweaked underway. Can't be done at the dock. You don't give enough info about your system to be specific but if you installed the EV-1 gyro with an ACU-200 autopilot and a p70 controller as an example you would need to fiddle with several settings.

I would start with Response Level. A higher number will give you better tracking but the pump will be running a lot more. Rudder Gain should also be tweaked. I would use a rudder indicator in any installation as a standard feature.

You should get an actual experienced Raymarine tech onboard and as tiltrider mentioned, browse Raymarine forum. (And I would start at the beginning and calibrate your EV-1)

Don't think you get rudder gain as a parameter on a EV autopilot. But I agree that the tech was a Garmin salesman.

Agree that the Raymarine should not be giving you problems if the correct size package is installed and all components working as needed.
The snaking is probably a setting issue as Raymarine autopilots have had a good rep for at least 20 years.
Lots of techs are not all that good...the easy way out or a new sale is a bigger feather in their cap rather than just doing what they should.

I have Raymarine system on my boat. The best help you will get is from factory tech support team. I was brave enough to install everything by myself, but all the settings was advised by tech support worked to my satisfaction.
Good luck.

Just got back up to the boat. The boat has a EV200 P70R powerboat pack and EV 200 hydraulic pack and ACU 200 processor installed in 2016. There is a pre existing rudder control indicator in the stern but not hooked up. The fluxgate compass in installed in the main salon in a cabinet not near any motors or pumps.
I am going to see if i can find another Raymarine tech if i cant fiddle with it more this week. What kind of hardover time do I want on it?

adornato said:

The boat has a EV200 P70R ....
I am going to see if I can find another Raymarine tech..

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For what it's worth, I had exactly the same model AP installed 2.5 years ago and all settings were done by the Tech in the slip! The EV200 has been working flawlessly with no additional tweeking. The boat is a 42' Ocean Alexander. Suggest you get another tech who has installed the EV200 in the past.

Codger,
do you have a rudder position indicator on your alexander?

adornato said:

There is a pre existing rudder control indicator in the stern but not hooked up.

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IIRC Raymarine has said in the past that a rudder indicator isn't required but is desirable. Having one reduces the settings that can (or need to) be tweaked in the AP setup process.

adornato said:

Just got back up to the boat. The boat has a EV200 P70R powerboat pack and EV 200 hydraulic pack and ACU 200 processor installed in 2016. There is a pre existing rudder control indicator in the stern but not hooked up. The fluxgate compass in installed in the main salon in a cabinet not near any motors or pumps.

Click to expand...

I think you mean the white EV-1 sensor unit is installed in the cabinet. The black fluxgate compass is no longer used. It's a solid system. An experienced "real" raymarine tech can do the setup at the dock. Anyone else I would expect tweaking during sea trial to make sure snaking is gone.

danderer said:

I installed an Evolution AP a couple years ago. Night-and-day compared to the previous Raymarine AP I had (circa 2006, but I am convinced that unit had an underlying hardware problem I never located). The new Evo is fantastic in comparison. No snaking.

I do have a rudder sensor. (One comes with the AP, but I simply reused the one from my old AP rather than run new cables).

The Evo APs have very few setting compared to previous generations. Basically run it through the learning process and that's that. I don't know that there are many settings to "redo", and coupled with the fact he wanted to sell you a new AP suggests he is not someone I would count on for help here.

Ask Raymarine tech support: Raymarine forum

Click to expand...

tiltrider1 said:

The Raymarine forum is very good at solving problems.

Click to expand...

Agree, Give them a call and/or post on the Raymarine Forum......

SoWhat said:

I think you mean the white EV-1 sensor unit is installed in the cabinet. The black fluxgate compass is no longer used. It's a solid system. An experienced "real" raymarine tech can do the setup at the dock. Anyone else I would expect tweaking during sea trial to make sure snaking is gone.

Click to expand...

If there is an unused rudder sensor from a prior install, there may also be an unused flux gate from a prior install. If the EV-1 was installed in a very wrong place it might cause snaking. So is it the EV-1 (about 4" diameter white disk) or a flux gate (about 2.5" diameter black dome) that you see?

I'd hook up the rudder sensor. It's useful to see the rudder position when maneuvering, even when not on autopilot.

Mine will only snake when running downwind, or whenever my wife waves around an iron skillet in the galley....

I did have to replace a rudder sensor recently after 15 years. They do go bad..

You should have three or four sensitivity type settings they help with the preciseness your probably on the moat sensitive try one of the others. I think its like Power, Pleasure, Tug, ext or something like that. Put it on the least precise setting for a big slow boat and see if that helps, it did a lot for mine. When its on the most precise setting it overcorrects a lot with a bigger slow boat.

Autopilot problems

I have gone through Raymarine, B&G, Garmin on various boats over the years and for me personally I only use Simrad for my AP and Garmin for all else. That’s what works for me.

adornato said:

Codger,
do you have a rudder position indicator on your alexander?

Click to expand...

Yes, and I center the rudder every time before I back out of the slip. Once, it was hard over to starboard when I backed out and when I started down the fairway the boat went hard to starboard. My bow thruster saved my ass from running into another slipped boat.

The EV 200 is a great AP!~
Try this: Note: The Cruise setting will hold a very tight coarse but the AP pump may work too hard depending on the seaway you're in.

On my older RM ST6001 AP it would slowly snake 10 degrees either side of the base course. Very frustrating in the ICW! Turns out the default setting for AUTOTRIM is 2. Going to AUTOTRIM OFF stopped it completely.


Look in your manual for a setting that does this function on your AP:
...You may also need to adjust the AutoTrim setting. AutoTrim determines how quickly the SmartPilot applies ‘standing helm’ to correct for trim changes (caused, for example, by changes in the wind load on the sails or superstructure, or an imbalance of engines).

Fred Fritz in Petaluma was recommended to me by Raymarine when I installed with his help. He has been installing a Raymarine almost forever. I’m sure he can help.

followup for all those who offered advice. we hooked up the old rudder position indicator and re booted the autopilot and there has been a 90% improvement in snaking behavior.

case closed. thanks for all your comments