rudder design

[Brent Swain]

Comparison with other similar boats will give you an idea of what works.
Comparison is a good starting point in any aspect of yacht design.

[larry larisky]

Originally Posted by Brent Swain

Comparison with other similar boats will give you an idea of what works.
Comparison is a good starting point in any aspect of yacht design.

since you never show the plans of the boats you pretend to have designed how do you know the first thing about yacht design since you are not a yacht designer (you own admission).

[ImaginaryNumber]

Originally Posted by Eric Sponberg

Dave Gerr just wrote a series of three articles for Professional Boatbuilder magazine on steering and rudders. They appear in the issues: Dec/Jan 2006, Feb/Mar 2006, and April/May 2006. You can see these issues online at www.proboat.com for free. This is probably the most concentrated material on rudders ever written, and it should answer your questions.

Eric

Does anyone know if these articles are still available online anywhere for free?

Also, does anyone know if this Westlawn student manual is available for purchase?

http://www.westlawn.edu/news/index.a...ayfile=SG2.htm

[Eric Sponberg]

Originally Posted by ImaginaryNumber

Does anyone know if these articles are still available online anywhere for free?

Also, does anyone know if this Westlawn student manual is available for purchase?

http://www.westlawn.edu/news/index.a...ayfile=SG2.htm

You can buy downloadable back issues of Professional Boatbuilder for $5.95 at: http://www.woodenboatstore.com/products.asp?dept=7

I don't know about the Westlawn notes, you'll have to ask them directly.

Eric

[Silver Raven]

Originally Posted by tspeer

Why don't you just put a deeper blade on the existing rudder head? It looks like it already kicks up. The deeper rudder will put more load on the head, so you might have some problems there. But it would be the fastest way to experiment with different possibilities.

Instead of the Vara, I'd just go with a transom hung rudder of the daggerfoil type. Much lighter and simpler, and you can pull it up with the keel. You could also revert back to the original rudder very quickly to be class-legal for one-design racing.

Gooday 'Tom' - Why ?? - "The deeper rudder will put more load on the head, etc etc". Surely if the 'rudder' is designed better in both section, foil shape & profile - - then why would the load on the head - not be much less. All this has been done before - back in the 60's & 70's in 'A', 'B' & 'C' class cats.

Increased efficiency decreases load - top & bottom & makes for better balanced helm & faster boats. Yes/no??? Ciao, james

[philSweet]

SR, check the date on that post by tspeer. The dust on it made me sneeze

[Silver Raven]

Sorry 'phil' Please accept my appologies - - we're a long way behind the rest of the world - way down here. The subject is still relevent however - as it's being discussed in another part of these forums. Please recover from your 'hay-fever' soon & I hope you find enough tissues to last you out the planting & harvesting season. Ciao, james

[ImaginaryNumber]

Originally Posted by Eric Sponberg

You can buy downloadable back issues of Professional Boatbuilder for $5.95 at: http://www.woodenboatstore.com/products.asp?dept=7

I don't know about the Westlawn notes, you'll have to ask them directly.

Eric

Thanks, Eric, for the Woodenboat Store link.

[daiquiri]

Originally Posted by Silver Raven

Increased efficiency decreases load - top & bottom & makes for better balanced helm & faster boats.

What force component (or moment) do you intend when you say "load"?

[Silver Raven]

Originally Posted by daiquiri

What force component (or moment) do you intend when you say "load"?

'Daig' - Gooday - the force c/m we used was the formula we learned in 4th year @ 'HN University' in the applied quantum physics course we took & then applied & used sucessfully to win a few 'world chanpionships' in both 'A', 'B' & 'C' classes. Some of those figures were used directly in formulating the foil section, priofile & weight considerations when we built one of the many 'wing-masts' we built back in the late 60's - which were some 38' high x 14" thick x 60" -fore & aft - at the bottom & 28" x 4.5" at the top x 100lbs (45.359 kgs) x 128 sq ft, c/w all rigging & fittings. - A world leader of over 6 years.

'Daig' - I don't understand your "do you intend when you say load". I do believe that whole statement was a question & should have had a '?' at the end. Yes/no???

I couldn't help wondering if you were 'taking the micky out of me' as they say - here in Australia & New Zealand - where much of the 'cutting-edge' of the leading development in AC 45's, carbon wing-masts, etc etc is taking place, as well as building some of the finest yachts in the current world of racing.

My confusion is probably due to the circumstances that I'm approaching - - ie. - when I get on-board my little toy - 45' x 1750 kgs x cruising tri & put a newer wing mast on it & then go cruising in & around SE Asia - I - like Gary - will try to send you some pictures.

Sure hope that will do & in the meantime - y'all over there do have a grand day & remember to enjoy whatever sailing - that you get time to do. Ciao, james

Oh & to all the rest of you - have a great day & GO sailing (same thing - eh?)