Subject: Re: [harryproa] Re: Proa Squared Development
From: Rick Willoughby
Date: 6/6/2011, 8:06 PM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

The board does not need much rounding on the edges because it is not working through a range of angles like the rudders.


I have been working on a 12% thick section with a 4% camber.  So the leeward face is still slightly convex; not flat.

You should be able to shift area from the current rudders to the board so total blade area is not much more than you have now.

Something that might be useful for producing hands free video is a little camera like this:
http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=10093
It could be mounted on the boat to give a close up view of things.  They will hold about 45 minutes of recording.  You can edit the good bits into a smaller clip. 

Rick
On 07/06/2011, at 9:26 AM, tsstproa wrote:

 

Yeah thats next I remember your discussion on toyote.

Todd

--- In harryproa@yahoogroups.com.au, Rick Willoughby <rickwill@...> wrote:
>
> Todd
> You should test a dagger board in the middle of the hull with the two
> small rudders. Give the board a slight camber so it is lifting to
> windward.
>
> Another observation I mentioned with the drive test is that the boat
> crabbed sideways quite easily. A decent dagger board would prevent
> this.
>
> Rick
> On 07/06/2011, at 6:09 AM, tsstproa wrote:
>
> > Development of Proa Squared along with boards tested.
> >
> > http://www.youtube.com/watch?v=DG1LuSq_CLg
> >
> > In the video the proa squared free sailing version worked fine with
> > the single 4 1/2 sq inch with about 3- 3 1/2 sqinches of board
> > submerged. It actually tending to bear off the wind more than I
> > expected with this single board down. So the bigger boards where
> > not tested in single board down configuration. I proceeded in using
> > the two of the smallest boards for two board down sailing. What I
> > experienced was heavy weather helm no matter how hard over boards
> > were held over they were over powered by the sail the model was
> > uncontrollable shunting, sailing in a straight line etc...Lots of
> > finesse required and even then very frustrating. So I jumped up to
> > the second 1 1/4''x 5'' larger retangular board wha la great
> > success balanced sailing and shunting just a touch of weather helm
> > coming out of a shunt . On on the hard though hands free sailing
> > straight.
> >
> > With this design of craft shunting happens so fast the advantage of
> > leaving both boards down is quit significant maintaining control
> > and predictability allows me to sail faster not the other way
> > around fight helm to maintain control.
> >
> > enjoy
> > Todd
> >
> >
> >
>
> Rick Willoughby
> rickwill@...
> 03 9796 2415
> 0419 104 821
>


Rick Willoughby
03 9796 2415
0419 104 821


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