With out relying heavily on boards alone you might consider hull depth and shape. With out meaning to step on anyones toes Look at dick newicks trimarans MOXIE is just one of my favorites. V baby V the power of V .... Don't see why a V can't be manipulated to ride alittle higher. If it makes you feel any better Oracle has some V shape in hulls.
Look at the lift on leeward float bow isn't being buried?
http://www.youtube.com/watch?v=oNiJxGnl2f8
I seen 3 really nice composite big steering wheels for 195.$ us at a locol surplus store about 3 foot diameter. Didn't ask the construction but light and stiff with maybe a 1/8 sponge grip wrap. If anyone needs a really nice wheel for steering?
Todd
--- In harryproa@yahoogroups.com.au, Dennis Cox <dec720@...> wrote:
>
> OK!� I am about to drill down to China.� (Hope that expression has the same
> meaning where you're from... I guess not... if you're in China)� I hope I
> can�explain this without putting you to sleep... and hopefully you can slap me
> out of it.� There are two issues I want you to entertain... efficiency and
> strength.� We want to go fast... and we want to stay in one piece.� I think
> those are universal.� We are "thinking" about a HarryProa (nothing else really
> matters)...
> �
> Efficiency
> If you raise the front rudder, you have to kick the back rudder till the angle
> of attack (AOA)�of the entire hull counters the leeward force of the sails.� We
> all know that low aspect foils are inefficient.� And the leeward hull is about
> as low aspect as you can get.� So even though its big and strong, there is a lot
> of side slip going on.� We are aiming for Europe and we hit Africa.� We also
> have a LOT of induced drag.
> �
> Now if we lower the forward rudder, we can get the two rudders (acting as highly
> efficient, high aspect foils) doing all the heavy lifting.� We can now set the
> AOA of the hull to be zero by having positive AOA on the rudders.� In this case,
> the hull is presenting the least drag it can possibly do and the rudders are
> taking all the load.� So we're kicking ass and taking names, until...
> �
> Strength
> ... you start realizing that we need to design for the "lifting windward hull"
> case.� As an approximation... the leeward force is about equal to the windward
> hull's weight.� Split that in two (for the two rudders) and for my
> case...�that's 4000 lbs (17 kN).� (Forgive me Rob... you have the best
> pictures)�http://www.harryproa.com/building_Vis/Vis_img_feb11.htm.� By the time
> you get the moment arms into the issue, the bottom rudder post would be taking
> somewhere around 11,000 lbs (50 kN).� I�haven't analyzed these, but I�think
> these�supports would have troubles with that load.� Fortunately, they don't have
> to in Rob's design!� If you'll note the rudder isn't balanced so the lateral
> forces acting on the rudder are resisted... by... you got it... the helmsman.�
> If I were to take a WAG, I'd say Rob has a mechanical advantage somewhere around
> 100:1 on the wheel.� So to hold that, the helmsman would have to supply... 100
> lbs (500 N) On each wheel... not bloodly likely.� So, Rob has�used the helmsman
> as a force limiting transducer.� Briliant!
> �
> Before I saw Rob's elegant�brilliance, I was going to make my rudders
> (near)�balanced.� I wanted some helm feel, but I didn't want a work out or blow
> the autopilot.� Then I realized using delicate members like Rob, I'd soon tear
> them off while sipping my afternoon tea and steering with one finger.�
>
> �
> Can anyone... tell me how I can have my rocket ship and eat it too?
>