autopilot broken mid mozambique channel

[whipper_snapper]

this is mrs w_s

w_s is on a cat in mid mozambique channel and the auto pilot has just broken

he says the 3 soldered wire connections fell off the linear rudder position sensor on the autohelm ST6000, and he needs to know the wire colours / connections

Can anyone help?

Thanks

M W S

 

[Guest]

There is not much to go on but from the manual for the ST6000 but they mention
Red
Green
Blue

If these are the colours he has then using the setup instructions it says to reverse the direction of the rudder display the red and green should be swapped.

From this I assume that:
Blue is Signal
Red is positive
Green is negative
(Shield is shield)

I assume since the computer end is not soldered he means the linear end of the wire.

So he must find out which of the three connections is the "wiper" of the linear variable resistor.

The blue must go to the wiper.

Just connect the other 2 anyway around. When he goes through the setup and finds the rudder indicates the wrong direction then just reverse the Red and Green in the computer connector box as per the instructions.

That the best I can do since I am so far from the boat. I hope it helps.

 

[whipper_snapper]

Hi This is mrs w_s again

Thanks for answer which seems to have helped

I passed on your message to w_s and here is his reply

Thanks, that confirms that we rewired it OK and that it is dead. Any
ideas on a mail order place that can DHL to Mayotte ?! The autopilot
seems totally dependant on the rudder angle sensor, it was working
perfectly till that died. We are now trying to work an overloaded cat vs
horrible head-winds with 1 crewman who cannot hold a course ! Luckily he
is a good cook or he would have been overboard!

 

[Guest]

Post deleted by danfoley

 

[rogerthebodger]

I think it would be quicker to DHL from france to Mayotte tham from Durban in my experance.

 

[Guest]

I do not know your installation but some require rudder references because the drive would destroy something if it hit the end stop.

However, Autohelm range have in general 4 drive settings. The 3 and 4 are for rudder reference. Simple models do not need references.

If yours is safe, i.e it will not burn out or pull the back of the boat off; try setting the drive parameter to 1 or 2.

In the manual is refers to "Future use" (it is in the calibration menu).

It is a long shot and assumes that autohelm used the same software as previous models and did not disable the non rudder reference drive modes.

Even if there might be problems with the end stops you could turn down the rudder setting so it worked only a little and never tried to do full lock.

Mad idea but it would be worth a try!

 

[BlueSkyNick]

we had a similar problem last week - the pivot bolt between the end of the hydraulic arm and the rudder control lever sheered off coming up thruogh Raz de Sein. We had a new one made up in L'Aberwrach but then found the cable had been pulled out of the rudder sensor in the process.

So we still had to steer by hand for the rest of the trip.

The current problem is that the rudder sensor is a totally sealed unit, so I am intrigued that w-s has been able to get to the connections.

On mine, I am looking at causing damage to get it apart, then a major fiddle to put it back together because of the spring. Only alternative is a new unit at £140ish.

Anybody know the trick to opening and reclosing this unit?

 

[whipper_snapper]

Hi all

I am now in Dzaoudzi, Mayotte after an epic trip. Details to follow! In the end a faiilng autopilot was the least of our concerns. We are however still waiting for the new sensor, sent from UK some 10 days ago and will leave for Kenya as soon as it arrives. Forecast is perfect of course, watch that change when we are ready to go.

How to get into this sealed unit _ desperation!! We eventually got to the sensing unit itself _ its neat how it works _ but ours doesnt.

W_S Stranded in paradise.

 

[Richard10002]

[ QUOTE ]
we had a similar problem last week - the pivot bolt between the end of the hydraulic arm and the rudder control lever sheered off coming up thruogh Raz de Sein. We had a new one made up in L'Aberwrach but then found the cable had been pulled out of the rudder sensor in the process.

So we still had to steer by hand for the rest of the trip.

The current problem is that the rudder sensor is a totally sealed unit, so I am intrigued that w-s has been able to get to the connections.

On mine, I am looking at causing damage to get it apart, then a major fiddle to put it back together because of the spring. Only alternative is a new unit at £140ish.

Anybody know the trick to opening and reclosing this unit?

[/ QUOTE ]

Nick,

I opened mine up, (cant remember why), and got it back together with a lot of fiddling with the spring, and it's worked fine since.

Very simple inside... red green and blue wires soldered to a potentiometer IIRC.

Probably worth prising it apart if you have nothing to lose, soldering the wire/s back on, and see how you go.

Raymarine have an answer with some details on the transducer here:

http://raymarine.custhelp.com/cgi-bin/ra...amp;p_topview=1

Hope this helps

Richard