If i recall, russ brown's proa, inigo's proa and the big green french proa all have autopilots - look them up in the web

--- In harryproa@yahoogroups.com.au, Paul Wilson <opusnz@...> wrote:
>
> The book "Pen Duick" by Eric Tabarly has a chapter devoted to wind vanes
> for high speed sailboats. It is quite technical but it has a good
> write-up on the issues involved. Also "Self Steering for Sailing Craft"
> by John Letcher is an awesome book, the bible on wind self-steering, IMO.
>
> I have also seen windvanes on multihulls but the ones I have seen would
> probably rarely get over 15 knots. I think the problem is the shift in
> apparent wind with varying wind speeds but also the foil design. I
> think it is a real challenge to have a foil large enough for slow speed
> but small enough that it doesn't fly apart at high speed. At high speed
> (>15 knots?) you can get severe vibrations, cavitation, and over
> steering since the amount of rudder deflection required to turn the boat
> is much less at high speed. It is also always a trade-off with
> windvanes between being light (delicate) but responsive and heavy
> (strong) and unresponsive. This is big challenge with heavy
> monohulls, but an even bigger challenge with high speed multi-hulls.
>
> As far as electronic autopilots go, use a tiller pilot if you can.
> They are much less money and more reliable. Wrap them in a plastic bag
> to keep the spray and water off and they will last much longer since the
> seals on some are pretty poor. The flux gates inside are fragile and
> have tiny wires that are easily damaged but if you treat your
> tiller-pilot like eggs and don't bang it around, it should last many years.
>
> My personal experience is that the new Raymarine wheel pilots are
> junk. The old ones like in the old Autohelm 3000 were poor but the new
> wheel mounted units are even worse. The engineers have gone for tiny
> motors in order to get the current draw down but it is a poor trade-off
> in reliability. The tiny motors burn out, the belts regularly fail and
> they are made almost entirely of crappy plastic parts. Raymarine does a
> great business in selling parts for them. If you get WD-40 near the
> plastic, it will fall apart. The motors are actually cheap hobby motors
> that are less than $5 from China but Raymarine glues a gear on that is
> impossible to get off and then charges you well over $100. Needless to
> say, I am not a fan.
>
> If you have wheel steering and can't use a tiller pilot, it is much
> better to have the type that fits direct to the quadrant via a ram or
> direct to the steering cables with an electric motor. The hydraulic
> units are OK too but can be noisy. All these options are expensive and
> relatively power hungry.
>
> Cheers, Paul
>
> On 7/9/2011 7:40 AM, Michael Fischer wrote:
> >
> > I have seen windvanes on multihulls.
> >

> > On Fri, Jul 8, 2011 at 2:27 PM, bjarthur123 <bjarthur123@...
> > <mailto:bjarthur123@...>> wrote:
> >
> >
> >
> > i have been told by the manufacturer and read accounts online that
> > self-steering wind vanes do not work on multihulls:
> >
> > http://www.selfsteer.com/windvanes101/index.php
> >
> > they could not explain why. i'm guessing it has something to do
> > with the large difference between true and apparent wind due to
> > the high boat speeds, as what else is different with monohulls.
> > but it is not clear to me why that would be a problem.
> >
> > has anyone had experience with such a system? or have any idea why
> > it doesn't work on multihulls?
> >
> > they draw NO (zero) power! a beautifully clever idea.
> >
> > ben
> >
> >
> >
> > > what kind of autopilot would you recommend for a harryproa?
> > >
> > > which types have been used successfully?
> > >
> > > energy draw?
> >
> >
> >
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