Autohelm ST 4000+ - crazy steering

[dunedin]

Recently gave up on the old wheel drive for the ST4000+ after many repairs to the clutches andguidee wheels and invested in a new model wheel drive - which should be a plug in retaining the old control units.

As time short the yard fitted it but could not do sea test. Since then it has been driving me crazy

Initially was driving like a drunkard in any slight waves, unusable under sail and even doing huge swerves under engine. A bit exciting at 6knots Read the flippin manual and tried adjusting the sea state control to 1 = Auto and rudder gain down from 5 to 2.

This reduced the drunken swerves - but now hardly alters course when do +10 etc. This is not a huge issue as can alter by hand and reset.
Big issue is that it now is constantly nudging back and forward a tiny bit every 1 to 2 seconds even motoring in a millpond - ended up switching off and simply locking the wheel as driving me mad

Any ideas ?

 

[jimi]

I had exactly the same problem and its a setting , I can't remember it at the moment but I've got it written in the back of the book. I'm down the boat at the weekend and will dig it out!

 

[FWB]

Failure of Rudder Reference Unit ?

 

[Boathook]

When I fitted my new wheel autohelm earlier this year the sea trials also set the autohelm up and calibrated it, etc. Even though you seem to be using the control units the whole system may still require a recalibration ?

 

[snowleopard]

I had this problem for several years and it drove me potty, especially as the hydraulic drive is a noisy beast. In the end I spotted what was causing the trouble. The hydraulic ram that operated the rudder to which the helm position sensor was attached had come loose at the static end and had worn slots in the mounting plate. Each time the pilot ordered a change of helm the pump activated but the rudder didn't move until all the slack had been taken up so it was applying more helm - meanwhile the other rudder was moving correctly. The result was large swings from side to side, 10°+ either side of the course.

Your problem won't be exactly that but the symptoms suggest either slack in the drive train or incorrect input from the rudder sensor unit. Firstly check the ram and sensor unit are moving correctly when the helm moves, then suspect the sensor. If the sensor is integral to the drive unit it may be more of a problem.

Hint: when getting into the steering compartment, don't damage your knee. (don't ask!)

 

[slipknot]

I have exactly the same problem. ST4000+ and just retrofitted the new wheel drive unit.

Mine does exactly as you describe. Have done the recalibration bit. I dont have a rudder reference sensor fitted (shouldnt need one) My best result is when I set gain to 2 and the constant correcting is eased, but then doesnt hold couse well.

I occasionaly get the head unit beep, give no data and then the reading is circ 60 deg off.

My next visit to the boat will involve an inspection of the inners of the fluxgate compass along with re making all connections at the head unit and at the fluxgate compass

I will let you know if I have any success. Likewise please let me know if you have a breakthrough!

 

[dunedin]

Thanks for all the very helpful replies - though doesn't sound there are any silver bullets, will work through some more options when get back to the boat

One bit puzzles me though - what is the rudder reference unit referred to and does it exist on a wheel pilot ?

 

[sailorman]

Thanks for all the very helpful replies - though doesn't sound there are any silver bullets, will work through some more options when get back to the boat

One bit puzzles me though - what is the rudder reference unit referred to and does it exist on a wheel pilot ?

http://marine.eshopsale.com/Simrad-.-Rf300-Rudder-Feedback-Unit

 

[FWB]

Part number M81105 I would have thought essential for 4000+ wheel.

I've had 2 fail....in exposed position so not their fault... when they fail symptoms are as you describe.
You can see if you have one by looking at the display, it will show the rudder angle.If it doesn't move with the rudder then it's faulty.

 

[haydude]

Part number M81105 I would have thought essential for 4000+ wheel.

I've had 2 fail....in exposed position so not their fault... when they fail symptoms are as you describe.
You can see if you have one by looking at the display, it will show the rudder angle.If it doesn't move with the rudder then it's faulty.

Or whoever replaced the wheel drive accidentally disconnected one of the rudder sensor wires? Check all the wiring over.

 

[snowleopard]

Or whoever replaced the wheel drive accidentally disconnected one of the rudder sensor wires? Check all the wiring over.

I had the link from the sensor unit to the rudder come apart. The autopilot slammed the helm hard over and we started going round in circles.

I'm not sure which a/p systems actually have a separate rudder position sensor. Presumably mechanical systems can get their information from the ram mechanism. No idea for wheel/belt drives.

 

[Boathook]

I had the link from the sensor unit to the rudder come apart. The autopilot slammed the helm hard over and we started going round in circles.

I'm not sure which a/p systems actually have a separate rudder position sensor. Presumably mechanical systems can get their information from the ram mechanism. No idea for wheel/belt drives.

It was an optional extra on my spx5? at the beginning of this year. The on/off/calibration for it is in the menu. The comment that if the display does not move it is busted would be quite valid and possibly making the autohelm take the helm hard over to rectify.

 

[dunedin]

Thanks for the input

I will take another look when back at the boat but had not previously noticed any rudder sensor being present. Ditto was not aware that the ST4000+ showed the rudder angle at all - though may be on an optional page

There was no risk of dislodging wiring when replacing the wheel pilot as the one cable attached to the old wheel drive unit was simply plugged back into the new one. All done above deck

Will have a look

 

[FWB]

The display will not show rudder bar if there is no reference unit fitted.
Fitting one will improve the autopilot performance enormously.

 

[SAMYL]

My wheel pilot, same model, does not have a rudder reference unit and works perfectly - but don't put a mobile phone anywhere near the head unit......

 

[haydude]

Thanks for the input

I will take another look when back at the boat but had not previously noticed any rudder sensor being present. Ditto was not aware that the ST4000+ showed the rudder angle at all - though may be on an optional page

Will have a look

The rudder position is shown with vertical segments at the bottom of the main screen, no special page.

 

[snowleopard]

I will take another look when back at the boat but had not previously noticed any rudder sensor being present. Ditto was not aware that the ST4000+ showed the rudder angle at all - though may be on an optional page

A small pic but you can see at the bottom of the screen a scale with 0° in the centre. Underneath is a series of bars to show the rudder position (the example is showing 7° stbd helm). I don't know whether the bars or the scale as well will be missing if there is no rudder reference unit.

With my hydraulic steering I can't mark TDC on the wheel so I find the display invaluable.

 

[slipknot]

My system does not have a rudder reference unit fitted. It is an option which does not routinely need to be fitted on a 4000+. When one is fitted and the head unit settings are set to use it's output to display the actual angle of the rudder, sensed by the rudder reference unit.
Fron the manual, the scale at the bottom of the display is named 'rudder or steer direction indicator.
As my unit does not have the rudder reference unit fitted and not set to take readings from one, my unit still displays the amount of rudder angle needing to be applied on the display which I assume the unit calculates due to the extent it is off course, and not taken from the actual amount of rudder applied taken from the sensor.

Having attempted to discover the cause of my problem, I understand that it is not uncommon for the system to work perfectly well for many years ( without a rudder reference unit) then the crazy steering kicks in. So I am of the opinion that the rudder reference unit is not the problem. I still plan to carry out the check of all connections as per my previous post and hope to post good news. I often sail shorthanded and have to have the system working reliably, so it must be fixed and will update when resolved.

 

[dunedin]

So resurrecting this old thread ..... as basically not had a working autopilot these last 3 years !

The local agent fitted a rudder sensor .... but that didn't help at all, and been round and round evey setting and resetting to no avail.

A friend kindly has lent me a spare ST4000+ head unit which we recently fitted. Physical installation a dawdle, as all wiring beautifully colour coded on units and just two wheel nuts to hold (great design by Raymarine).
But setup has me a bit confused as to how to get this working right. Been through all the dealer setup options to check settings, and to change from Tiller to Wheel mode.
But two odd things
(a) Compass reading is showing miles out - was never very precise but now about 190 degrees out! The compass sensor is unchanged, so resumably sending out the same signal, so how is it appearing to be swapped north to south?
(b) Rudder position is shown as off the scale to port. swapping round connections, as suggested in manual, simply has off the scale to starboard.
Quick patch suggested for (b) was to simply disconnect rudder sensor again. Not ideal but done

On a quick test was marginally better - steered Ok under motor in flat water. But veering 30 degrees either side of course under sail, still in flat water - vastly over steering.
Resorted back to simply locking the wheel

Any suggestions before I bin the whole lot

 

[jimi]

the setting I had which worked for me in a Beneteau 331 were:
Gain 2
Response 2
Autotrim 2
Drive Type 2
Rudder Damping 4

Good luck!