Join Date: Nov 2006
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What I ended up doing
I thought I'd close out this thread with a description of the solution I eventually worked out.
Instead of making a trim tab and using a wind vane, I redesigned the rudder blade so that it pivoted forward instead of hanging down vertically. This made it very close to completely balanced. I also made it larger, making it possible to steer the boat while moving at half a knot or so. This made is possible to use the tillerpilot (Simrad TP32) under all conditions, from very light winds to gales, including big quartering waves from hurricane Bertha. I added 75W of amorphous solar cells, which are cheap and work even on overcast days, so that I never had to run the engine to provide juice for the autohelm or the nav lights.
For self-steering while going to windward, I added a mizzen. The boat initially was rigged as a yawl, but the mast and other rigging were lost over time. I added a tapered flagpole for a mast, and a 2" aluminum tube for a sprit, and used the original mizzen sail, which is still in fine shape. When moving to windward, the idea is to trim the mizzen so that it is just luffing, and lash the tiller so that it counteracts weather helm and then some. Then as the wind shifts, the mizzen keeps the boat from falling off too far. But I would like to add a wind sensor to enable the autohelm's sail to wind feature. This will be handy not just when beating, but also on other points of sail on the open ocean, when I want to catch a few winks and don't care about the exact course. In all, these changes worked out very well for me, and I had an easy sail, single-handing from Florida to Massachusetts (except for Bertha, but that's another story). While out on the ocean, I think I hand-steered an hour or so total during the entire trip.
Based on my experience, I would give the following advice:
- Skip the windvane; they are expensive and, I understand, don't always work. My whole solution cost me around $1k.
- Redesign the rudder so that it's close to 100% balanced. I used 2 slabs of 3/4" marine ply wrapped in 3 layers of cloth, and it works fine.
- Use an inexpensive autohelm (the TP32 is around $600) and some inexpensive solar panels to power it.