Any Raymarine experts around?

[arto]

My boat has a fairly ancient (ca. 2005) set of Raymarine kit, including an ST6001 autopilot and what I think is a Raymarine S1 course computer, along with a Raymarine fluxgate compass, and a set of pretty standard instruments, an RL70 pathfinder radar and display and so on.

Innocently trawling through the internet (I've almost reached the edge), I came across the novel idea that it is possible to improve the performance of the S1 and autopilot with the addition of a gyrocompass - or perhaps more accurately, a turn rate accelerometer. Back in 2005 it seems the original owner of my boat could have opted for this as an option but didn't. Back then, it was expensive, now less so (thank mobile phones and drones). You can now buy the necessary parts for a few pounds, or a fully assembled complete product for rather more - though still considerably less than the amount that Raymarine would have charged back in the day.

Curious, and by this time hooked, I bought one of these: Seymo Gyro autopilot V 3.06 - a gyro add-on which turns the S1 course computer into an "S1G".

I've installed this, and from a little testing, it seems to work - the autopilot seems more responsive. However, the "Sea Trial" instructions that Seymo (and Raymarine) provide for calibrating the gyro don't work. I start the "Autolearn" process and the boat proceeds to turn to starboard and go around in circles, rather than go from side-to-side as the instructions suggest.

Any ideas as to what might be wrong? Or how I might diagnose the problem? I've a multimeter to hand but I'm not sure what I should be looking for.

Thanks in advance for your insights.

 

[KREW2]

I have just bought a boat with Raymarine gear, of the same vintage. I had to replace the GPS antenna which failed. The replacement antenna available is different and does not wire directly into the Seatalk loom, this caused problems. I could either have the ST4000+ or the plotter working, not both. The problem was Seatalk, are you getting Seatalk failure messages?
I solved the problem by simply disconnecting the Seatalk cable from the back of the plotter.
All works well except the radar and plotter are now a stand alone unit, as is the autohelm, but I'm happy with that.

 

[davethedog]

We have the S3 course computer on our current boat and added the same Seymo gyro and have had no issues at all , was easy to connect with just 3 wires (if I recall) to the course computer. The sea calibration was also veery easy.

Is the unit away from electrical sources etc as in the manual?
Have you connected the 3 wires correctly, you can check this by seeing how many settings you have for sensitivity on the St6001 (3 normal, 9 I think with the added gyro)?

DTD

 

[Graham_Wright]

You need to check that the cable from the "gyro" (I agree with you it is not really a whirly, whirly thing) to the autopilot has low resistance. I had to extend the one supplied with mine and it then failed. Replaing the whole run with lower resistance cables (in my case silver plated and ptfe sheathed I had to hand) fixed the erroneous behaviour.

 

[arto]

Thanks for the comments. The Seymo device clearly works well for lots of people, but my boat's other electronics are old enough that plenty of interesting failure modes are possible.

> Have you connected the 3 wires correctly, you can check this by seeing how many settings you have for sensitivity on
> the St6001 (3 normal, 9 I think with the added gyro)?

Yes, this all works - and the "Autolearn" function only appeared once the gyro was connected.

I've been in touch with Seymo and they have asked for some voltage readings across the connectors which I will do when I next visit the boat.

From other reading, it seems that the three wires are a 12V supply, ground, and an analog rate of turn signal which ranges between 0V and 5V with 2.5V representing the idle state. It seems likely that low voltages indicate a turn to starboard and high a turn to port.

So I have enough information to do some diagnostics - now I just need some time and decent weather. This week is looking a little blowy :-(