Off-Centre Windvane Mounting?

[Buck Turgidson]

You clearly don't understand how each of them works. They're chalk and cheese.

They each use a vane to operate a servo tab which drives a rudder. In the case of the Navik that rudder displaces in an arch which drives the ships rudder through connecting lines, in the case of the AH the rudder replaces the ships rudder or the tab is placed on the ships rudder.

The gearing in each case is adjustable based on moment arm on pivot length and line geometry.

They both use exactly the same servo tab principle in one case more directly than the other.

Did I miss something?

Lift = Cl 1/2 rho V^2 S

that doesn't change regardless of whether you use a Servo tab or a servo pendulum.

 

[TimBennet]

Did I miss something?

Yes, you've missed the whole rationale behind the servo pendulum gear and why it made gears like the AutoHelm obsolete.

With the Servo Pendulum, the boat speed and flow of water past the servo arm adds dramatically to the forces the gear can generate.

 

[Buck Turgidson]

Yes, you've missed the whole rationale behind the servo pendulum gear and why it made gears like the AutoHelm obsolete.

With the Servo Pendulum, the boat speed and flow of water past the servo arm adds dramatically to the forces the gear can generate.

As it does with a servo tab. It's the V^2 in the lift formula

 

[TimBennet]

As it does with a servo tab. It's the V^2 in the lift formula

And the leverage between the length of servo arm and tiller lines and the mechanical advantage in the tiller or steering system?

All the details about the design and workings of the various systems are very well documented and have been proven for nearly 50 years.
You essentially are saying that everyone else's work and experience is wrong and you are right.

If you want to know why servo pendulum gears are an order of magnitude more powerful than vane / trim tab / auxiliary rudder systems, then read one one of hundreds of books or articles about the subject.

 

[Buck Turgidson]

And the leverage between the length of servo arm and tiller lines and the mechanical advantage in the tiller or steering system?

All the details about the design and workings of the various systems are very well documented and have been proven for nearly 50 years.
You essentially are saying that everyone else's work and experience is wrong and you are right.

If you want to know why servo pendulum gears are an order of magnitude more powerful than vane / trim tab / auxiliary rudder systems, then read one one of hundreds of books or articles about the subject.

Or do a degree in aeronautical engineering?

 

[G12]

I'm in the process of fitting my hydrovane from my old boat onto my latest boat. She's got a transom hung rudder and I'm having stainless brackets made up so I can have it centrally mounted. I could have gone off centre but didn't fancy the idea of reduced performance upwind.

I found the HV very effective before and look forward to it working away silently once again.