Another autopilot question - rudder position sensor?

[neil1967]

My AH6000 autopilot has given up the ghost and I intend to replace the control unit etc and retain the Raymarine Type 2S linear drive. The current set up does not have a rudder position sensor, but worked fine. I am told that the linear Raymarine and Garmin/Jeffa drives are more or less interchangeable. The Garmin website says that to use the Garmin GHP Reactor autopilot with a Garmin linear drive does not require a rudder position sensor, but if a third party drive is used, then a rudder position sensor is needed. Anyone have any experience of this? Is a sensor actually needed when using a Raymarine linear drive with a Garmin autopilot, or are Garmin just covering themselves in case there are some drives that are otherwise incompatible?

Neil

 

[RupertW]

I find it useful on the display (but can otherwise see how far round the wheel is going to see sails unbalanced or over-pressed) but I did think that autopilot software can learn sea-state more quickly with a rudder sensor.

 

[Foolish Muse]

I have always strongly advised against mixing systems. When (not if but when) something goes wrong, neither supplier will be able to fix it. They will both blame the other. I have direct experience with this nightmare. So unless you have a very compelling reason, stick with one.

 

[dom]

As I understand it on Jefa drives the rudder feedback can be integrated for Garmin, NKE and Raymarine autopilots albeit with slightly different parts and that the is surprisingly little:
http://www.jefa.com/steering/products/drives/linear.htm

Jefa are very helpful so prob best to email them and also Raymarine directly as it may depend on the individual systems.

 

[pvb]

My AH6000 autopilot has given up the ghost and I intend to replace the control unit etc and retain the Raymarine Type 2S linear drive. The current set up does not have a rudder position sensor, but worked fine. I am told that the linear Raymarine and Garmin/Jeffa drives are more or less interchangeable. The Garmin website says that to use the Garmin GHP Reactor autopilot with a Garmin linear drive does not require a rudder position sensor, but if a third party drive is used, then a rudder position sensor is needed. Anyone have any experience of this? Is a sensor actually needed when using a Raymarine linear drive with a Garmin autopilot, or are Garmin just covering themselves in case there are some drives that are otherwise incompatible?

No, for best operation, a rudder feedback is needed with most modern autopilot computers. The Garmin linear drive is just a Jefa drive with integral feedback (I have one).

 

[neil1967]

Thanks - I'll dig deeper. I note that the Jeffa site states that their drives for Garmin have a built in position sensor, so perhaps I just have to bite the bullet and add one separately. The reason I want to reuse the existing drive is simply cost - why replace the drive when it is serviceable? Cactus list the Garmin GHP Reactor corepack at 1025UKP + VAT and the equivalent Raymarine unit at 1925UKP + VAT, hence why I would like to use the Garmin, plus my existing instruments are Garmin.

 

[knuterikt]

As far as I know Garmin can supply a separate rudder sensor.
reusing the existing drive unit seems like a sensible solution, linear drives don't have any complicated interface with the AP.

 

[nauticalnomad]

I bought a Garmin head unit because the Jefa drive motor i purchased, i was told that you dont need a rudder feedback unit if its paired with a Garmin headunit. As the Jefa is built on the Garmin head unit and there is an inbuilt sensor.. Well thats complete BS...
I sailed from the Uk to Portugal and the new autopilot started to send the boat round and round in circles...
I then pull into Portamao and ring Jefa to be informed that "This happens all the time and that Garmin wont let them use non Garmin parts".. So they tell the customers to replace the internal rudder feedback sensor with the aftermarket one.. They didnt mention any of this pre-purchase.. What if i had of been half way accross the atlantic.

 

[tjbrace]

When I replaced my NKE ap. with Garmin I reused the linear drive and rudder sensor. All works so far (5 years).

 

[danielefua]

1) autopilot computer + drive unit of different manufacturers.
As far as the two units are compatible there is no serious reason to avoid this case. The main points to check for compatibility are i) kind of interactive command i.e. solenoid-like, PWM, or else, and ii) voltage and power compatibility. Consider also that most of the manufacturers of autopilot computers do not produce drive units anyway.
2) Rudder Feedback.
Having a RF installed is always advisable although, in principle, some smart autopilots might be able to do without it; personally I would never trust completely an autopilot without a hardware rudder feedback. The RF and the autopilot computer should be built by the same manufacturer unless one is able to deal with electronics. Whether the RF is integrated in the drive unit or it is an external unit makes very little difference.

Daniel