Autopilot choices

[qsiv]

The new boat is now in build, and I need to finalise the electronics choices. The main instruents will be B&G. Plotter/radar, Raytheon. The remaining item is really the autopilot (which must be easy to to at least disconnect from the quadrant if not leave ashore). As I see it there are 3 choices B&G (it will integrate better and the steer to true wind / VMG is a key asset), Raytheon (are the new G series as good as they say), or NKE (I love the radio remote and MOB function - but B&G have one coming).

I'd welcome peoples opinions on any of these. I've previously had ST6000/7000 systems, which have never let me down, but their ability to control a boat downwind is woeful.

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[sailorman]

i belive that Oyster fit 2 x rams on raytheon.
one either side of the quadrant, this is supposed to speed-up reaction down wind+ u have a spare already "plummed-in".

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[Talbot]

I have bought the S1 system from Raytheon but without the gyros (can be added if needed) Not yet fitted, but there are good comments for the gyro version from a lot of racers. The S1 has an uprated linear drive from the old ST5000+. I would recommend Datayacht at Lymington for a quote.

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[HaraldS]

My boat was originally fitted with a type 300 from raymarine, with an ST6000 and an ST7000 controlhead. The drive unit is from Whitlock and fits the Mamba steering. While the drive unit is very robust, however the clutch (magnetic field) alone eats a lot of power (30W).
The type 300 course computer had trouble supplying clutch and all the instruments with its built in 24->12V inverter and so it played up a couple of times.
Two years ago I fitted a 400G which has more power and also has the giro controled heading refernce. It has worked fine since.
With respect to downwind sailing, my boat tracks quite nicely, so even the 300 did ok, but certainly the 400G is better, and the NMEA heading refernce that is giro compensated and sent our 10 times a second was a big improovement stabilizing the Simrad Radar on course-up or north-up.
The only problem with the 400G is, that track mode isn't implemented very well. Means if you engage it while just very slightly off track, it kind tries to force the boat there no matter what; so I rarely use it in that mode. Maybe a software update will help, I need to check that. The good news is that this is the first unit from ray that has flash rom, so updates should be quite easy.
I also used steering relative to the wind and the results were mixed, in more difficult situations I found it better to keep it on heading. Though I must say that I use it with the ST6000+ and ST7000+ heads and not the 01 types that have new software to enable some of the functions like sailing to true wind. The default is apparent and that changes with acceleration and decelleration of the boat.
In general a good unit.


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[qsiv]

Thanks

The 400 G sounds the only viable unit. The new boat will definitely need TWA steering as speeds of 25 knots are quite on the cards. Stability downwind will be non existent - the boat apparently handles like Eurofighter at speed, highly responsive.

The key asset that the B&G pilot will bring (other than TWA) is that the pilot has acces to the polars, and can steer to optimum VMG both up and down wind - leaving crew to trim sails accordingly, which could be useful when racing short handed. The one thing they DONT have at the moment is the radio remote - only NKE do that at the moment.

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[AlanPound]

I have the (older, rather cryptic) NKE gyropilot on a Mystic 60 (ft) ketch - it copes well with the control forces, and is miles better than the Cetrek pilot it replaced (although I kept the hydraulics - they preceded the Cetrek pilot, and is an old Neco unit, made in fact by Hydraulic Projects).

The radio remote is comfort on a lone watch in bad weather...

But my demands on it are simple - I really only use a fixed heading - none of this TWA stuff, I am not sure how it might be interfaced to do that (although there would probably be a way of driving it using Maxsea - it seems to do most things...)

Alan

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[qsiv]

I've always thought the NKE interface to be unusual - and the ergonomics somehow quaint - but the French love them, and the Open Classes thrive on them (although B&G and Raytheon both seem to be making inroads).

If B&G ARE producing the radio remote, then I suspect that will offer everything desired. I just wish TackTick produce a full on performance sailing version of their kit, but it doesnt look as though it has plans to launch anything along those lines in time for next season.

Now, all I need is a name for this thing!

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[HaraldS]

Never sailed an Eurofighter! But think that equally important to the right course computer would be the proper references, means exact heading and roll information. The fake giros, like in the 400G help with correcting the heading, but I haven't seen wind instruments factoring in the rolling motion of the boat, but the swinging masthead adds quite an error to the proper TWA calculation. They all seem to fix that by averaging over some time, but that would be responsive enough for your Eurofighter.
Maybe a combination of a satellite compass (GPS based with three antennae) and a good wind sensor at masthead might do the job. Singularly both would be available from Furuno.
As a course computer the 400G seems a good base, and it has a real powerfull 32 bit micro, but then it's all a matter of programming;-)
Haven't missed radio control yet, otherwise I'd have build myself one. Sending the right coammands into SeaTalk isn't difficult, have reverse engineered most of those when I had some strange trouble with magnetic variation.
Where do you need the remote control, versus a bunch of control heads in convenient places? Just curious as I made a long cable to go up to the first spreaders with my 600R for coral waters, but so far never used it.

Must be fun sailing your 25kn rocket!


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[qsiv]

I'm with you on roll induced pollution of AWA - that's something that is being worked on, not least by someone else on the Forum. B&G can already do that (in particular <A target="_blank" HREF=http://www.sailmath.com/special_projects.htm>SailMath's Wave Processor</A>), which replaces the B&G Performance processor, and adds even faster gyros.

As for the remote - anywhere forward of the cockpit basically. Having been the victim of a gust or two when dropping the kite, the ability to bear away would be nice. As for climbing the mast the concept of climbing a thin carbon stick makes me go cold - now doubt it would be do-able in extremis - but only in calmish seas. thank you. The GPS compass sensor is far too heavy (and I'm not sure that it would add much if anything to performance that a good 3 axis solid state gyro wouldnt).

The one trick that the NKE pilot + remote has is the ability to auto heave to if you fall overboard (crew members can wear transmitters without controls for the same reason). You'ld want to make sure the hatches were battened down as the boat would wind up with it's spreaders in the water - but I suppose that makes it easier to climba back aboard...

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