I glue on another piece to form the trailing edge, and shape the rudder.
The entire trim tab is then covered with roving and epoxy, which I hope will keep it watertight.
My old Aries vane took the helm most of the way around the world, but it needs to be rebuilt. I had constant problems with the kick-up coupling to the servo-oar, as well as the mounts. Due to the turbulence behind the main rudder, the vane kept developing play where it connects to the mounting brackets. The soft aluminum kept wearing down and I never found a way of stopping it.
So I have decided to dispense with it altogether and install a trim tab directly to the rudder. This is a far more simple solution to the problem of self-steering, especially with a stern hung rudder. In this case the vane can be directly attached to the trim tab rudder shaft. As the wind vane steers the trim tab, the trim tab steers the main rudder which steers the boat.
That's the theory anyway, now for practice. I'll use a 5/8" SS shaft and
bolt on mahogany boards with four 1/4-20's to form the trib tab rudder.
I glue on another piece to form the trailing edge, and shape the rudder.
The entire trim tab is then covered with roving and epoxy, which I
hope will keep it watertight.
Having learned the hard way about machining costs, I decided to attach
the trim tab using hardwood, which is ash, I think, for the
receipt from the lumber yard said hickory, but it looks like ash
to me ...
I drilled 3/4" holes for
the 5/8" shaft, but filled the insides with epoxy and 12 ounce
roving. Here I have the installation roughed out:
The air paddle is 4mm plywood with a counterweight (for which I used a collar zinc). It is mounted on two hardwood blocks bolted together with hole going down the center for the rudder shaft. The lower bolts (with the round handles) can be tightened to clamp it onto the shaft, otherwise the air paddle moves freely.
