Challenge: Self-Steering

[barnakiel]

Except if your boat is 44 then the Navik is smallish.

b.

[Brent Swain]

My trimtab moves the rudder from side to side, the rudder is left free. There is no way you could get enough power in the trim tab alone, to steer the boat in rough conditions. I don't know why you'd want to, given the power and simplicity of using the trimtab to steer the rudder. Airplane folks can explain the principle .

[obrienkev]

This video explains how to use a 100 AMP alternator as a welder:

https://www.youtube.com/watch?v=ZKSXgTEx3mQ

[NevilleCat]

Originally Posted by barnakiel

Except if your boat is 44 then the Navik is smallish.

b.

They did used to make a Super Navik for big boats. It dispensed with the trim tab arrangement of the Navik but still used the bell crank mechanism rather than gears.

[obrienkev]

Here is another video showing how to weld with an alternator:

https://www.youtube.com/watch?v=fcExTf2bVUI

[NevilleCat]

It seems to me that, once you have a trim tab arrangement set up on your rudder you could also use a horizontal axis vane to drive it, either via crank or using a small quadrant.
This is how James Wharram's simple design works on his catamarans which have a similar rudder arrangement to yours.
One advantage is that the vane can be remotely mounted if you have a real estate shortage on the stern.
Of course you could do this using a vertical axis vane as well, but I believe horizontal vanes are favoured for more power and accuracy.
Wharram's website has the design available for simple construction.
You can see it in operation HERE

https://youtu.be/HwEejk7bhCw?si=Ij-qNdIn2fUwmFLO