[hpv-boats] Activity

[Bob Stuart]

Leaping Lizards, Larry.

I'm not quite sure what you were describing, but suddenly I'm  
wondering about a fin that moves vertically, instead of having to  
react against another fin.  With the right linkage, the legs could  
tilt it for steering, or run it in short strokes for shallow draft.

A lot of fin drives use flex to accommodate changes in direction, but  
that usually gives the foil the opposite camber to what you want.   
Rigid fins on a hinge with limited motion are an improvement, like  
the symmetrical wing sections of an aerobatic aircraft.  However, it  
is possible to get beneficial camber by using spars fore and aft,  
with a flexible material in between.

Bob Stuart
Sent from The Country Formerly Known as Nice.

On 2-Jan-12, at 12:55 PM, Larry Smith wrote:

> Hi Bob, Curt, All,
>
> I'm still linked and receiving the rare contribution, but have been  
> inactive for quite awhile myself.
>
> At 71, diminishing years and energy have found me putting my boat- 
> thoughts/efforts into somewhat larger sail/powered craft, but I'm  
> still appreciative of the efforts of Rick and others who are  
> pushing HPB envelopes.
>
> I wish the main body of discussion had not so completely moved to  
> other venues, but maybe the increased level of technology and  
> required mathematical and computer literacy made that inevitable.
>
> Part of the fun for me was leaning against a figurative tree  
> watching the early "back-yard" inventors fumble forward. I've  
> learned a lot, but improving my knowledge was a low bar, compared  
> to  getting to the level of today's fore-fronters.
>
> Bob, ever since Harry Bryan's first fin-drive showed up, the  
> graceful swishing of a fin drive and the natural looking magic of a  
> boat moving under "fish power" has intrigued me.
>
> Slow moving/turning parts with surprising resulting movement are  
> fascinating to me. (In my mind, I still carry the image of my first  
> sight of Knapp's Sea Saber pulling smoothly away with its  
> relatively slow-turning 18"(or so) prop.
>
> I would like to see the result of extended, concerted efforts by  
> such a community as used to exist on this site, directed toward a  
> state-of-the-art fin set-up.
>
> I used to think some split-fin arrangement might best answer the  
> yaw issue, with the fins sweeping opposite directions at a given  
> time (think swim fins on a diver swimming on his side).
>
> I also imagined a forward turning rudder-fin actuated in phase with  
> the (single) fin's stroke to "lift" the bow to the appropriate side  
> to counter the fin's yaw force. Additional drag, of course, but a  
> fixed forward fin also has drag, but offers less correcting "lift"  
> due to restricted angle of attack, no?
>
> Anyway, tossing ideas into the midst of this group has always been  
> fun. :-)
>
> Very nice to hear you are still out there Bob!  "High tech" wood  
> and rope. I like it!
>
> Best wishes and Happy New Year to all,
>
> Larry
>
>
>
> On Jan 2, 2012, at 7:52 AM, Bob Stuart wrote:
>
> Didn't you get a flurry of activity from Rick Willoughby recently?   
> I have not had my own keel wet in six years.  I realized that my  
> boat work was probably not building a sustainable, useful  
> technology, and lost interest.  HPBs appeal to simplicity, while  
> metal and water demand complexity.  I'm still interested in the  
> possibility of fin drives, made from carved wood and rope.  A high- 
> tech version could be as fast as a propeller.
>
> Bob Stuart
> Sent from The Country Formerly Known as Nice.
>
> On 2-Jan-12, at 8:38 AM, Curt Chambers wrote:
>
>> Hello.  Hello,  out there.  Is anybody there?  Is anybody doing  
>> anything
>> worth reporting?  Or is my receiving faulty?  I have not gotten  
>> anything
>> for months (years?).  Just for the record, Nauticraft is still  
>> here; we
>> had a reasonably good year considering the economy and hope to have a
>> better one here in 2012.  Well, anyway, a Happy New Year to everyone!
>>
>>
>>
>> Curt
>>
>>
>>
>> Curtis Chambers
>>
>> Owner/Pres.
>>
>>
>>
>> Nauticraft Corporation
>>
>> 5980 Grand Haven Rd.
>>
>> Norton Shores, MI  49441
>>
>> 231-798-8440
>>
>>
>>
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>
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