Does the ST4000+ require GPS?

[mz4wheeler]

Just curious:

After a great weekend of sailing/motoring using my newly (to me) installed autopilot, which worked flawlessly, I powered down my MFD (to stow it).

To my surprise, my ST4000+ started a small to large "S" pattern... I was under the impression the external compass connected to the AP would keep me going straight.

Is this normal behavior, or do I have more calibration to do? I do have a rudder sensor installed. Does the St4000+ NEED COG (from GPS)?

 

[centerline]

no gps required.. it has the option to interface with a gps unit if you choose to do so, but the fluxgate compass will allow it to steer a straightline course if its working properly... it may need to be recalibrated.
any magnates or magnetic objects within 3-4 feet could have an effect on the system... this includes small things such as steel zippers or snaps on jackets/shirts, eyelets on boots or anything else that may be stowed near the compass....

 

[centerline]

but then... if you just powered down the device that was telling it what to do, without you setting it manually, it will wander like a lost puppy... it needs input to know which direction it is supposed to be going. use the manual buttons after you take the interface away...

 

[mz4wheeler]

but then... if you just powered down the device that was telling it what to do, without you setting it manually, it will wander like a lost puppy... it needs input to know which direction it is supposed to be going. use the manual buttons after you take the interface away...

I tried a couple of things.

First, I placed the AP in standby, turned off MFD, reengaged AP, result: S-turns

Second, I recycled power, reengaged AP, result: S-turns

 

[kloudie1]

Was it in "Track " mode and if so, did you turn that mode off after turning off the MFD?
Seems like ya have to hold Auto and Standby together to get into mode then scroll through to Track mode and toggle off.

 

[rardiH36]

Do you have the manual? Performance is variable depending on user set-up and calibration.

The pdf's of manuals are maintained within this site at:

http://sbo.sailboatowners.com/downloads/Hunter_gen_96382241.pdf

and

http://sbo.sailboatowners.com/downloads/Hunter_gen_42654057.pdf

Also I've attached a pdf of the ST4000+ repair manual below:

 

[mz4wheeler]

Was it in "Track " mode and if so, did you turn that mode off after turning off the MFD?
Seems like ya have to hold Auto and Standby together to get into mode then scroll through to Track mode and toggle off.

No, it wasn't in track mode. Just aim, press auto, lock drive clutch. I'll go through the calibration again and give it another go.

 

[mz4wheeler]

Do you have the manual? Performance is variable depending on user set-up and calibration.

Yea, I'll give it another go. It might make sense to calibrate the unit without the GPS to see if that makes any difference.

 

[Bill Roosa]

If memory serves you can set a primary course device and a secondary. If GPS is the primary it might be having issues "thinking" about no GPS and wandering off course till it is pretty certain that the fluxgate is correct and a course correction is in order. If the flux gate is the primary then there are algorithms that the computer uses to "smooth out" the course corrections. Also check the settings on, I think it is called "response" Higher numbers makes the computer try harder (rough weather setting) to hold a straight course.

 

[Ken Cross]

I haven't tried this with my ST4000 but on tiller pilots my cell phone messes them up big time if it's within a couple of feet. Was your phone near the fluxgate?

Ken

 

[mz4wheeler]

If memory serves you can set a primary course device and a secondary.Also check the settings on, I think it is called "response" Higher numbers makes the computer try harder (rough weather setting) to hold a straight course.

I don't recall seeing a primary course device. I'll definitely check that out. Also, yes, I dod discover the rudder gain, which made a huge difference.

Thanks for all the suggestions. I'll report back once I give it another go.

 

[Maine Sail]

This typeof behavior is most often:

#1 Bad flux gate signal

#2 Lack of rudder signal

#3 Course computer on last legs. The ST-4000 was not one of Raymarine's more reliable AP's and they no longer service the head/course computer...

 

[mz4wheeler]

#1 Bad flux gate signal
#2 Lack of rudder signal
#3 Course computer on last legs.

Thanks for the suggestions. Both the fluxgate and rudder sensor is brand new, and the ST4000+ was recently blessed by Raymarine when it was sent in for repairs, but the issue turned out to be another problem (previous owner told me this).

I'll re-check all of this. It was tracking straight as an arrow for many hours last weekend, and I don't mind having a GPS on (it always is anyway).

I just heard of folks using these units stand-alone, although all the experiences I've had on other peoples boats where the autopilot was working fine, then it suddenly goes out of whack. These experiences were with an older AutoHelm-type units (ST4000), not the ST4000+.

Thanks to all!

 

[mz4wheeler]

Here is an update: I'm happy to say that I finally got the ST4000+ performing perfectly! This includes basic motoring --AND-- under sail. I am absolutely amazed how well it performed under a 15 knot wind while sailing close hauled. How did I fix it?

Well, for one thing, I discovered the "Catalina cocktail", which apparently also works for Hunters as well [grin].

The "Catalina Cocktail" suggested by Raymarine is:

Rudder Gain 2, Response 2, Auto trim 2, Drive type 2 (hydraulic).

I tried that, which vastly improved the tracking (with/without GPS), however it would STILL get out of whack on occasion, (little S turns, over-correcting to large S turns). It didn't happen THAT often [grin]. I'm my mind, the ST4000+ was "good enough".

I then (later) I discovered this website, which was really a guy who managed to create his own rudder transducer using an old transducer made by VDO.

http://northernlight.vermontficks.org/rudder_sensor.html

I read this, only because I like this sort of clever creative thing. But the thing the caught my attention was this comment he made:

"Without the rudder reference transducer, the ST4000+ autopilot display appears as follows."

"After installation of the rudder reference transducer, each time power is applied the autopilot recognizes the presence of the transducer and displays the rudder bar at the lower edge of the screen."

I thought for sure my rudder transducer was being recognized by my ST4000+, but I was flat WRONG! I thought this because in "Auto" mode, the curved rudder bar was there on the bottom of the display.

In STANDBY, the ST4000+ *MUST* display the rudder bar, but mine didn't! That was the "A-Ha" moment. Suddenly, this link became much more credible and I totally followed what this guy said, and followed the procedure he outlined to get the ST4000+ to "correctly" recognize the rudder transducer.

After this, along with the "Catalina cocktail" settings the performance of the ST4000+ was simply astounding.

Folks, the ST4000+ absolutely *NEEDS* the rudder transducer. It is really NOT an "optional" item. You need to trust your autopilot, and not accept that "for the most part", it performs well but "occasionally" it goes out of whack... NO NO.

It now steers the boat just as good as human, motoring or sailing.

Next time you power on the ST4000+, check to make sure the rudder bar is there in STANDBY.