Orlov,
Clever design and nice sketches.
I know you indicate the mock-up dimensions are not to scale. How far out of scale are they? I ask because the surface area of the trim tab seems insufficient to usefully steer the boat. Hopefully there's more surface are than the drawings suggest, or possibly your boat is so well balanced that tiny variations in rudder pressure will induce steerage?
Also, I will wonder aloud about the plan to connect the tiller pilot. As I mentioned previously, most steering vane/tiller pilot
rigs use the power of the vane to steer the boat on a
compass course provided by the tiller pilot, so as to reduce power consumption and wear/tear on the tillerpilot. Your plan seems to be to attach the tiller pilot to the trim tab, and give it less rudder surface area with which to steer the boat. Maybe I'm missing something, but wouldn't that make the tiller pilot work harder?
Finally, I still don't like the idea of mucking up the flow over the rudder with a trim tab and all the pintle/gudgeon mounting hardware. Again, I would want to be able to get the self steering
rig out of the water when I didn't need it.
Sorry to come across so critical - I don't mean it personally. I just see some issues with the plan and thought I'd mention them for consideration. You seem to have a knack for this, so I sincerely hope you prove me wrong on all counts and I look forward to hearing how the project goes.