This is pretty well what I have come down to. I would probably have gone with
the older cassette rudders as most of the time I would be sailing in plenty of
water but plan to incorporate the rudders into the flare. I was also considering
having a sacrificial tip.
I worked out a curved blade for the cassette type that would remain balanced at
all depths but it would have been a pig to make and would have had some
interesting torques on it




--- In harryproa@..., "Rudolf vd Brug" <rpvdb@...> wrote:
>
> Hi,
>
> BD had the kick up dagger rudders. To be able to steer them you need balance.
> The old BD rudders worked, but only when fully down (2 m draught)
> The balance you need by canting the blade forward is gone when it's partially
retracted.
> That's why BD's new rudder is on a shaft in bearings hanging from the beam.
> Bearings are on a tube through which the shaft can be pulled up. That way
balance doesn't change.
> Kick up function by having shear pins holding the bearings in place.
> This seems to be a difficult problem in bigger boats. The rudder boxes on BD's
beams are big and heavy.
> I'll post some photo's soon.
> Regards,
>
> Rudolf
>
>
>
>
>
> ----- Original Message -----
> From: George Kuck
> To: harryproa@...
> Sent: Friday, July 10, 2009 4:30 AM
> Subject: Re: [harryproa] Re: MODERN NAMES of things/ Rudders
>
>
>
>
>
> Hello Robert ,
> I think it should be possible to have a daggerboard rudder that can
kick up. It would work on a ruder that can rotate 270 degrees but would be a
problem on 360 degree rudders. All that is needed is a kick up dagger board
case. This is what is used on the F32. Take a look at the F32 rudder upgrade
plans.
> http://www.f-boatmart.com/home.php?cat=255
>
> I think the original rudder on Blind Date is a dagger board type but I
do not know if it can kick up. What ever happened with the new rudder for Blind
date ? It should be possible to make a kick up case that the dagger board can
go through. That would allow you to raise dagger rudder part way up for shallow
water and it can still kick up.
>
> Rob, what type of rudder is on the current 12 M Harryproa plans, Is it
a dagger board rudder ?
>
> Happy sailing,
> George Kuck
> Chestertown, Md.
>
>
>
> --- On Thu, 7/9/09, Robert <cateran1949@...> wrote:
>
>
> From: Robert <cateran1949@...>
> Subject: [harryproa] Re: MODERN NAMES of things
> To: harryproa@...
> Date: Thursday, July 9, 2009, 7:33 AM
>
>
> Sounds like you've got the winter blues. You certainly have got
stuck into the rebuilding but can imagine it can seem interminable at times. I
am pretty impressed at the rate of progress.
> There is a plant biology paper on Hypolithic Cyanobacteria in the
Tanami Desert ticking away (green slime that grows under rocks living on the
light that manages to get through the quartz) but mainly I am organising some
house plans for moving back down to Eden. It is to be a mud brick house in the
town so it may cause a bit of a stir, but should be reasonably cheap and very
energy efficient. I was hoping the admiral was going to retire next March so I
could get back to being a beach bum again but she was give a promotion and
decided to hang in for another year or so. She is in the same line of business
as Rob's wife. We plan to visit Rob when he moves up to Qld and get some sailing
in.
> I have not changed what I want in a Harry for a while now, but am
still not sure what what to go for in the rudders. It's is easy to have kick up
or retracting but difficult to get both. I have played around with telescopic
rudders and a shaft that moves up a little way. I have looked at rudders that
kick up by pivoting on the shaft and by the shaft letting go at the bearings.I
am tending to go for the shaft letting go at the bearings and allowing a small
amount of retraction and maybe a sacrificial tip. - In harryproa@yahoogrou
ps.com.au, Doug Haines <doha720@ > wrote:
> >
> > hi robert
> >
> >
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