I agree Rob's original design is probably the best solution. After all he did go out and do the actual testing and didn't lose sight of his goal of lightweight and simple. They are proven to work and achieve all the desired features (lift able, kick up, reversible, serviceable) with a minimum of fuss
My only concern with the original design is the lower pivot mount, which I feel is to, low and will become a hand break when the boat is pushed. I have considered other ways of mounting them higher but the problem is the same as the beam mounts they get heavier the further they are from the water
My most recent thoughts are trim tabs on (close to) both ends of the lee hull bottom to counter the asymmetric thrust /drag forces of the Harry (weight to windward) design. They would be semicircular self-retractable (spring loaded), and set in slot at a fixed angle or could be in a drum for extra adjustment and complication.
If the rounding up forces were removed or reduced the beam mounted rudders would come into calculation for me. At the moment I feel the beams mounts are not wide enough apart to perform this job with out being to large.
I am open to being convinced otherwise though
Rob Rassy
--- In harryproa@yahoogroups.com.au, "von Balluseck, Fedor" wrote:
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> Nice discussions!
> Think the drum 'outside' is going to be in size comparable to the first generation of rob's rudders - if not bigger - like on Visionary.
> Keep in mind those rudders are fairly big - and to get the balance right the rudders have to be either angled or the moved about15-20% back (longitudinal? ) So the drum is big - not sure but would guess 60-100cm's on Visionary.
> Maybe you can reduce the size of the rudders if you go for additional leeway protection measures - but that stirs up the 'additional boards question.
> Browse back in the posts - there was a long discussion on multiple boards or a lee-board that could pivot. Rick W makes a point that against intuition and leeboard on the WW side of the lee hull would be most efficient.
> I believe Arttu's Ono visionary has added 2 boards to the original 2 rudders - and he has shared some comments on how this is working (but no protection against grounding)
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