Raymarine S3 Giro choices.

[Seven Spades]

I have an S3 auto-pilot without a gyro fitted. I have been looking on eBay and there seems to be two different makes of Gyro's for sale. One is call "Ray Giro" by Seymo Technologie and the other one is called "Yaw Gyro" by JLC Enterprises.

Can anyone throw any light on the differences between them and was their an OEM Raymarine original gyro?

 

[Keith-i]

If you don’t mind tinkering with a little bit of electronics then you can quite cheaply add your own with just a couple of components. I did by following the experiences on www.portanna.org although sadly it looks like that site has gone. If you’re interested I’ll see if I can dig out a schematic.

 

[Yngmar]

The original one was called Autohelm/Raymarine/Raytheon Gyro Plus (later Gyro Plus 2). Part numbers can be found on the Seymo site. Someone with some electronics knowledge probably opened up one of the £700 Raymarine units, figured out one with almost the same functionality could be made for under £10 and started making and selling them for £200, making a nice profit and showing what a joke marine electronics pricing really is. The copies are likely both the same internally.

We have a Seymo one which I got for not much money from a fellow forumite. I fitted it on our older Type 300 autopilot, which greatly improved its ability to steer straight in big seas. It only uses it when switched to response level 3 (the highest on these units - I think your later model has 10 response levels instead of 3 and uses the gyro in levels 7-10 or something like that - the manual will confirm the details, which I'm a bit fuzzy on).

You could also build your own. CF thread here: http://www.cruisersforum.com/forums/f13/raymarine-gyro-sensor-upgrade-for-25-a-53175.html

Web Archive copy of the Portanna article Keith mentioned: https://web.archive.org/web/20160502121517/http://portanna.org/tip/153-gyro-raymarine

As that was some time ago, it may now be difficult to find the matching parts, as gyro sensors have evolved a lot recently (thanks to the immense popularity of quadcopters).