Auto helm going crazy

woodster · Dec 3, 2015

have you checked to see if there is something metallic/magnetic close to your fluxgate compass

kloudie1 · Dec 3, 2015

Also check all the connections at the computer end.. a loose wire or bad connection can do that.. if you don't find something metallic (anchor, cooking utensils, canned food , etc) and don't find a bad or loose connection, next step would be to do a set-up for the autopilot.. If the problem is only while motoring, I'd look at connections very carefully.

centerline · Dec 3, 2015

the prop type or torque on the rudder isnt the problem... the function of the autopilot is the turn the helm whatever direction it needs to go to maintain its heading....
the exception to this is, a faulty motor without enough power to turn the helm, OR... an extremely stiff helm that cant be turned reasonable easy..

the problem will be with the fluxgate compass, either its faulty, or its proximity to other wiring, some magnetic metal or magnetic device in proximity to the fluxgat compass.
a wire loom is an often overlooked magnetic device, that could run close to the compass behind a bulkhead and is unseen.

Joe · Dec 3, 2015

Perhaps the compass in the autopilot is conflicting with chartplotter signal. Have you tried running without the chartplotter input?

Benny17441 · Dec 3, 2015

It seems you have excessive pull on the helm; check for a fouled or unbalanced prop. Not familiar with your auto helm unit but most have a gain adjustment for when encountering rough seas to allow the motor enough force to steer true. Perhaps the gain is all the way down or if not the motor may lack the power to control the rudder. Check the prop and shaft balance.

woodster · Dec 3, 2015

do you have a rudder position sensor installed it seems i read somewhere awhile back that it was better to have one than not and do you get this adverse condition when steering with the wheel only as well

JamesG161 · Dec 3, 2015

MORNING LIGHT said:
Hi yes I did check the flux gate compass and everything is fine.On our previous boat, I had my Garmin chartplotter wired to a Raymarine ST 2000 Autopilot and it worked just fine and when we bought this one , I kept my Garmin chartplotter and wired it up to the Raytheon st4000 autopilot but nothing seems to work.

You must calibrate your fluxgate compass first and then calibrate your ST4000, and finally tune the ST4000 to match your boat's characteristics ( which may be prop torque).
Jim...

PS: The Raymarine tech gave me the advise. I had to read the ST4000 manual which is available on Raymarine web site.

Meriachee · Dec 3, 2015

(If you're in the river, it's likely the crap that was dumped)
Did the autopilot work properly before you tried to integrate the Garmin?

JamesG161 · Dec 3, 2015

MORNING LIGHT said:
I called Garmin twice and had two different opinions on how to wired it up cause Raytheon work with Seatalk and my Garmin chartplotter with Nmea 0183 , so I have to solder some where.

Raymarine has NMEA to Seatalk box to plug and play.
I not sure, but the chart plotter is not part of my ST7000+ ( not 4000 ).
Jim...

JamesG161 · Dec 3, 2015

JamesG161 said:
I not sure, but the chart plotter is not part of my ST7000+ ( not 4000 ).

Let me clarify my own post.

My new Raymarine MFD a98 is connected to my existing ST7000+.
The course set by a route set on the Chart Plotter WILL control the ST7000+ only when....

You push the TRACK button on the ST7000+ display, and NOT done with the chart plotter.

Unless you push that button the chart plotter snoozes.

The Chart plotter can not tune the Auto Helm. In fact if you don't have the plotter and Auto Helm with matching bearings, when you do TRACK you will be off by ≈7° (my Magnetic bearing difference from True bearing). Both devices must be the same bearing standard. I make both Magnetic Bearings.
Jim...

centerline · Dec 3, 2015

MORNING LIGHT said:
We have a 3 blades prop that cause a lot of torque on the wheel when going at 5 knots. Or more that I have to correct by angling the wheel on starboard more than I should have to. Could the auto helm reading his direction being affected by the turbulence on the rudder ? When motoring for more than 5 hours, you can feel pain in your forearms !

if the helm pulls really hard to one side, its possible that you have a fouled or damaged rudder or bent rudder shaft, 'cuz it sounds like more than prop walk, even if the prop is damaged.... and although the motors for the autohelm is a strong and will in most cases power the motor til something slips, breaks or a fuse blows, it might be old and weak and not be able to overcome the pressure of the wheel quick enough...

Meriachee · Dec 3, 2015

This discussion has been had a few times. You need a protocol converter. It sounds like you've tapped into the network, without a thorough understanding of what you've soldered to what, and now it doesn't work.
Maybe put it back the way it was before you started, ensure it still works as original, and spend some quality time in the Ray site figuring out how to properly integrate it.

twalker H260 · Dec 4, 2015

Maybe I'm missing something. You indicate you have an st4000? Both the st4000 and st4000+ have nema in connectors on the control head. - between the rudder and compass connectors. Why did you have to do any soldering? Wire your Garmin nmea out + to st4000 nmea in +, Garmin power - will need a jumper connected to it that is connected to the st4000 nmea in - . Don't forget to change the communication settings on the Garmin out port you used to nmea as the Garmin data out can be set to multiple communication protocols.

Connections from GPS to st4000 are listed on page 67 of the manual. For Nmea outs on the Garmin check the manual for your particular model for the wire colours for your particular device. (Or post model number here!)

If you have a course set in the GPS and hit track does it give you appropriate heading etc? Or is it just the ap doesn't seem to be able to hold the desired course?

mz4wheeler · Dec 4, 2015

If you back off the throttle, does the autopilot still malfunction? Does it work better?

A few folks have said that there is something wrong with either the rudder alignment or prop (or shaft, bent strut, etc), causing over correction of the helm at higher RPMs. It seems that this might be a key to the issue.

Also, you really need a rudder reference sensor. My ST4000 was junk until I installed it.

Auto helm going crazy

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SBO Weather and Forecasting Forum Jim & John

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SBO Weather and Forecasting Forum Jim & John

SBO Weather and Forecasting Forum Jim & John

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