Re: Moving rudder & its effects
In a light boat the center of resistance is not fixed. You can
easily add more weather helm or lee helm simply by moving forward or
backward in the cockpit which in effect changes the center of
resistance. You can, in fact, steer the boat without a rudder simply
by changing your position fore and aft. Try it the next time you are
out sailing in light winds and need a little bit more of a challenge.
easily add more weather helm or lee helm simply by moving forward or
backward in the cockpit which in effect changes the center of
resistance. You can, in fact, steer the boat without a rudder simply
by changing your position fore and aft. Try it the next time you are
out sailing in light winds and need a little bit more of a challenge.
--- Inbolger@yahoogroups.com, "Joe Cronley" <joe@c...> wrote:
>
> In my continuing study of the His & Hers/Singlehand Schooner, I
have come to
> the following conclusions:
>
> 1) I will not scale the boat up, 19 feet is long enough for four
boys and an
> adult. I am reconfiguring the cockpits to make more of an open
racing dinghy
> style sidedeck/gunwale (think of a 470 or 505, even the
spectacular Flying
> Dutchman) . Current plan is to groove plywood in order to make
longitudinal
> curved sections and bend them into place in cockpit fore & aft of
mainmast
> step & bulkhead. Will experiment with some 1/4" ply first. This
would also
> be sealed (airbagged if I can do it economically) in order to
provide
> flotation and would be positioned to float the boat high on its
side and
> minimize swamping.
>
> 2) The rudder structure is too complex. While the (sic) foil
itself is very
> straightforward, it's mounted in a lifting trunk that comprises the
> rudderhead, shaft and foil on a lifting stage to allow beaching and
> trailering. A simpler solution is to create an outboard rudder:
simpler to
> construct and mount, can be constructed as a folding rudder,
allows more
> cockpit room. In appearance, it would be rather like a tiny Nova
Scotia
> pinky schooner: outboard rudder on a double ended boat with long,
curved
> tiller.
>
> While I haven't scaled it, this would place the rudder perhaps as
much as a
> foot aft of the current design. Due to the sternpost rake, the
bottom of an
> outboard rudder would nearly meet the bottom of the designed
rudder. My
> thought is to duplicate area of the rudder.
>
> Question: While the placement of center of effort and daggerboard
is
> critical for helm performance, how could I predict how this action
would
> affect handling? Ast the center of effort and center of resistance
are
> already defined and remain fixed, the rudder should just be a
trailing foil
> and not affect balance. Would likely affect control response under
sail and
> may even allow a smaller rudder, but I can't see it inducing
weather or lee
> helm. Perhaps it would limit control under short sail (reefed
main) as CE
> moves forward? Not even sure I would reef this boat, just drop
foresail and
> proceed under somewhat balanced main & Jib.
>
> Joe Cronley
>
> 678-352-8983
>
> cel 404-295-5712
>
>
>
>
> [Non-text portions of this message have been removed]
>
In my continuing study of the His & Hers/Singlehand Schooner, I have come to
the following conclusions:
1) I will not scale the boat up, 19 feet is long enough for four boys and an
adult. I am reconfiguring the cockpits to make more of an open racing dinghy
style sidedeck/gunwale (think of a 470 or 505, even the spectacular Flying
Dutchman) . Current plan is to groove plywood in order to make longitudinal
curved sections and bend them into place in cockpit fore & aft of mainmast
step & bulkhead. Will experiment with some 1/4" ply first. This would also
be sealed (airbagged if I can do it economically) in order to provide
flotation and would be positioned to float the boat high on its side and
minimize swamping.
2) The rudder structure is too complex. While the (sic) foil itself is very
straightforward, it's mounted in a lifting trunk that comprises the
rudderhead, shaft and foil on a lifting stage to allow beaching and
trailering. A simpler solution is to create an outboard rudder: simpler to
construct and mount, can be constructed as a folding rudder, allows more
cockpit room. In appearance, it would be rather like a tiny Nova Scotia
pinky schooner: outboard rudder on a double ended boat with long, curved
tiller.
While I haven't scaled it, this would place the rudder perhaps as much as a
foot aft of the current design. Due to the sternpost rake, the bottom of an
outboard rudder would nearly meet the bottom of the designed rudder. My
thought is to duplicate area of the rudder.
Question: While the placement of center of effort and daggerboard is
critical for helm performance, how could I predict how this action would
affect handling? Ast the center of effort and center of resistance are
already defined and remain fixed, the rudder should just be a trailing foil
and not affect balance. Would likely affect control response under sail and
may even allow a smaller rudder, but I can't see it inducing weather or lee
helm. Perhaps it would limit control under short sail (reefed main) as CE
moves forward? Not even sure I would reef this boat, just drop foresail and
proceed under somewhat balanced main & Jib.
Joe Cronley
678-352-8983
cel 404-295-5712
[Non-text portions of this message have been removed]
the following conclusions:
1) I will not scale the boat up, 19 feet is long enough for four boys and an
adult. I am reconfiguring the cockpits to make more of an open racing dinghy
style sidedeck/gunwale (think of a 470 or 505, even the spectacular Flying
Dutchman) . Current plan is to groove plywood in order to make longitudinal
curved sections and bend them into place in cockpit fore & aft of mainmast
step & bulkhead. Will experiment with some 1/4" ply first. This would also
be sealed (airbagged if I can do it economically) in order to provide
flotation and would be positioned to float the boat high on its side and
minimize swamping.
2) The rudder structure is too complex. While the (sic) foil itself is very
straightforward, it's mounted in a lifting trunk that comprises the
rudderhead, shaft and foil on a lifting stage to allow beaching and
trailering. A simpler solution is to create an outboard rudder: simpler to
construct and mount, can be constructed as a folding rudder, allows more
cockpit room. In appearance, it would be rather like a tiny Nova Scotia
pinky schooner: outboard rudder on a double ended boat with long, curved
tiller.
While I haven't scaled it, this would place the rudder perhaps as much as a
foot aft of the current design. Due to the sternpost rake, the bottom of an
outboard rudder would nearly meet the bottom of the designed rudder. My
thought is to duplicate area of the rudder.
Question: While the placement of center of effort and daggerboard is
critical for helm performance, how could I predict how this action would
affect handling? Ast the center of effort and center of resistance are
already defined and remain fixed, the rudder should just be a trailing foil
and not affect balance. Would likely affect control response under sail and
may even allow a smaller rudder, but I can't see it inducing weather or lee
helm. Perhaps it would limit control under short sail (reefed main) as CE
moves forward? Not even sure I would reef this boat, just drop foresail and
proceed under somewhat balanced main & Jib.
Joe Cronley
678-352-8983
cel 404-295-5712
[Non-text portions of this message have been removed]