Considering loads, wouldn't it be better to make it more oblong?
Rectangular certainly makes it easier to make straight and to attach
a rudder shaft compared to round.
I prefer this system as the foils can be tucked under the beams when
going through waves.
I was thinking about having the tiller on a horizontal pivot so that
it can face aft coming and going
Robert
--- In harryproa@yahoogrou
>
> G,day,
>
> The shaft is square, so the line can be lead up through a
pulley/fairlead
> on the front of the rudder shaft and through the bog which makes it
round.
> Pull up should not be necessary as drag and buoyancy should do the
trick.
> May need a line or piece of shock cord to get it clear of the water.
>
> Starting to feel a little irritated with myself that I spent a couple of
> grand on engineering for the two pin kick up system! KISS!
>
> Regards,
>
> Rob
> On Sat, Jun 7, 2008 at 6:45 PM, Robert <cateran1949@
>
> > If the shaft was a bit thicker with a hole down the centre to
allow a
> > pull down chord, I can't see any problem having a similar set up to
> > Harriette. If the bearings were above the structure of the the top
> > plate, there would only be a fairly small hole in the structure.
> > I was considering using some polypipe down the centre with a 90
> > degree hard plastic bend added at the point where the end of the lever
> > arm meets the shaft. This should provide a low enough friction to pull
> > the rudder down and it could then be cleated off on the tiller, or
> > even the tiller extension. Kicking up should be almost automatic.
> > It may be possible to have a lift up chord as well, providing the
> > rudder stayed with tiller steering.
> > Robert --- In
harryproa@yahoogrou
> > "Rob Denney"
> >
> > <harryproa@> wrote:
> > >
> > > oops, try this one.
> > >
> > > Robert,
> > > Good thinking. Also makes the beams 10% lighter (the weight will be
> > in the
> > > hull instead, so no nett gain) so easier to carry about. I will
> > change it
> > > when I see how the harriette rudders work and whether they will work
> > on the
> > > bigger boat.
> > >
> > > regards,
> > > rob
> > >
> > > On Sat, Jun 7, 2008 at 10:54 AM, captian_rapscallion <
> > > captian_rapscallion
> > >
> > > >
> > > > Could I take a look at the Rapscallion doc? it seems to be the
Kate
> > > > doc in the folder
> > > >
> > > > --- In harryproa@yahoogrou
<harryproa%40yahoog
> > <harryproa%40yahoog
> >
> > > > Denney" <harryproa@> wrote:
> > > > >
> > > > > G'day,
> > > > >
> > > > > Trailer proa renderings are in the Files section under Maxi
Trailer
> > > > sailor
> > > > >
> > > > > 'The ultimate trailer sailor/racer cruiser' is the
requirement for
> > > > > this boat. As fast as possible, with standing headroom, minimal
> > > > > galley, double bunk and a toilet. Trailering is mostly for the 5
> > > > > mile trip from home to ramp, but occasionally further afield.
> > > > >
> > > > > Windward hull is 7m.24', leeward hull 12m/40'
> > > > >
> > > > > The boat is 6m/20' wide in sailing trim, but telescopes to
3.7/12'4"
> > > > > wide for marinas and 2m/6'8" wide on the trailer. This is easily
> > done
> > > > > with composite beams. The mast and boom travel in cradles on
the lw
> > > > > hull deck, the beams under the cockpit. The trampoline is in two
> > > > > pieces split fore and aft. Each piece has a 25mm dia carbon
or alloy
> > > > > tube sitting in hooks on the hull and the beams. In the
middle is a
> > > > > thicker tube for each piece. When telescoping for marina
use, the
> > > > > lee hull tramp is lifted out of it's hooks and as the hulls
slide
> > > > > together it slides over the windward tramp, so you can still
walk
> > > > > across to the other hull. For light air races, it can also
be sailed
> > > > > like this. For trailering, the tramps and the telescoped
beams are
> > > > > quickly and easily removed and stored under the the cockpit.
> > > > >
> > > > > The mast is telescoped to 9.2m for stepping/unstepping
long
> > > > > pole, with a 4;1 blocjk and tackle on one end is inserted into a
> > hole
> > > > > in the deck next to the mast. The heel sits in a cup next to the
> > mast
> > > > > step. The blocks are tied around the mast at it's centre of
gravity
> > > > > approx 3.7m from the base and it is lifted up until the heel is
> > above
> > > > > the deck, then guided into the top bearing and lowered into
place.
> > > > > Unstepping is the opposite. Very quick and very safe.
> > > > >
> > > > > The reefing drawing shows sail areas incl mast of of 47
sqm/505 sq',
> > > > > 35 sqm/376 sq' and 22 sq m/236 sq m. Storm sail is 2 sq m/22.5
> > sq' of
> > > > > mast. Lots of sail up high for the light stuff, no drag or
weight up
> > > > > high for the heavy.
> > > > >
> > > > > Weight in sailing trim is 420 kgs and the payload 330
kgs/726 lbs.
> > > > > Overload could be as much again without it affecting anything
> > but the
> > > > > speed.
> > > > >
> > > > > Construction method for the hulls is partially glassed
panels joined
> > > > > and compounded, with flat panels for the rest.
> > > > >
> > > > > Bruce number empty is 2.34. With normal payload, 1.9. Hull
flying
> > > > > wind speed 10 knots, lower with the crew sitting to leeward.
> > > > >
> > > > > Inside the ww hull is a double bunk at one end and the
galley and
> > > > > toilet at the other. The galley space is large, but not all
of it is
> > > > > accessible. It will probably end up being accessed through a
deck
> > > > > hatch and used for storing fenders, etc.
> > > > >
> > > > > The cockpit is sheltered with a folding pram hood which will
ensure
> > > > dry sailing.
> > > > >
> > > > > The rudders could not be mounted on the telescoping beams,
so are in
> > > > > daggercases in the hull. Rather than use long tiller extensions,
> > > > > there is a short athwartships tiller (magenta in the renderings)
> > with
> > > > > an extension (green) attached to the tiller and a car on a
track on
> > > > > the deck. The car is pulled fore and aft by lines running to
> > > > > whipstaffs (vertical tillers, red) on the leeward end of the
> > cockpits.
> > > > > The lines are cleated on the whipstaffs so can be released and
> > easily
> > > > > replaced and retightened when the rudders are lifted and
lowered.
> > > > > This is a far easier system than wheel steering where the
lines must
> > > > > be released off the quadrants to raise the rudders.
> > > > >
> > > > > Comments, suggestions, criticisms welcome.
> > > > >
> > > >
> > > >
> > > >
> > >
> >
> >
> >
>
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