How close can the rudder be to the hull? Is wave action between the
rudder and hull a consideration or does the rudder only need to have
enough clearance to operate with out hitting the hull?

I've also been thinking about lee boards on the actual lee side of the
lee hull and was wondering if they have been tested on a harryproa?

--- In harryproa@yahoogroups.com.au, Rob Denney <harryproa@...> wrote:
>
> On Fri, Nov 9, 2012 at 8:08 AM, rob_rassy techsmart@... wrote:
>
> > **
> >
> >
> > Rob I do have more questions, but don't encourage me too much
> >
>
> The more the merrier!
>
> > ****
> >
> > I'm still confused how the foils can be liftable. When you say
"centre of
> > rotation is mid chord" do you mean the actual pivot point is mid
foil
> > thickness as well? (ie: The hinges will be recessed into the foil)
or
> > are the pivots mid distance along the chord and mounted outside the
foil. I
> > realise the foil will have less camber on the lee/hinge side, but
unless it
> > is negative the chord will lie inside the foil (won't it - correct
me if
> > I'm wrong).
> >
>
> The foil slides in a case. On the hull side of the case is a
> gudgeon/pintle arrangement. Means increasing steering loads as the
> rudders are turned, exacerbated if the blades are not swept back
and/or
> connected. If the loads are too high, the rudders will kick up. The
> gudgeons/pintles are mounted on a substantial shaft to allow this to
> happen.
>
> > ****
> >
> > My thought was to cant the rudder (tilt the bottom towards "under"
the lee
> > hull) to put the offset pivot point mid way on the longitudinal (Top
to
> > Bottom) of the rudder, the cant angle would be quite small to
achieve this
> >
>
> True. Definitely worth a try if the current setup doesn't work.
although
> the top will have to be firther away from the hull so that the blade
can
> rotate through 30 degrees each way without hitting the hull.
>
> > ****
> >
> > I reckon you might be right about the Blind Date crew wrestling with
the
> > rudders, if the direction of travel hadn't changed and the rudders
turned
> > it would be difficult if not impossible to force them round.
> >
> One of those things that comes with practice. BD crew in the videos
are
> first timers and apart from the helmsman and photographer, non
sailors.
> Interesting to compare them with first timers tacking or gybing a 15m
cat
> or mono, particularly one with an overlapping headsail.
>
> rob
>
>