Joe posted several messages and pictures of his boat in 2005. I reproduce them here because he seems to have a novel and elegant (and working!) solution to the rudder problem.
Starting with message #11570:
Joe Creecy:
Have any of you seen Joe Creecy 's rudders on the first proa file?
Michael Schach:
Thanks for the reminder, Joe. This is a very neat way of using Hobie
rudders to steer a proa. They kick up, too. Find diagrams and lots of
pics in the Photos (not files) section.
http://photos.groups.yahoo.com/group/proa_file/lst
MIchael
Dean Dibling:
Joe,
What are the last two pics in your file? Looks like a tensioning line
acting on some kind of lever with a pulley in the middle.
Thx
Dean Dibling
Joe:
Dean,
This is a little more than you ask for but your answer is in it. Look at
the first of my pictures. The first picture is a diagram depicting the
rudders using control lines between not one but two steering wheels. The
top steering wheel in the diagram steers the boat. The bottom wheel in the
diagram controls the shunt. When the boat is sailing along on one
tack/shunt the, shunt wheel is locked in position (locking system not
shown). You will notice by studying the diagram that if you turn the top
wheel with the bottom wheel locked that the rudders will turn in opposite
directions. (cw for one and ccw for the other or vice-versa). This action
steers the boat. Upon shunting you must turn the bottom wheel and that will
make both rudders turn in the same direction. That is to say cw or ccw. The
shunt wheel must be turned to its other stop (not shown) where the rudders
will have turned turned 180 degrees plus or minus a few degrees (I'll
explain later. I thought up this idea and built my proa to experiment with
it. But after I built my proa I realized I didn't have the resorces to set
it up so I decided to figure out how to get the same results with levers and
rods etc. instead. That is what the second picture depicts. Also if you
study the photos you can see how it works. But I will explain it again
here. There is a rocker arm that pivots in its center mounted to the end of
another arm. The rocker arm has, pivoted to each end, tiller extensions
which extend to the tillers ends. When the rocker arm rocks the rudders are
made to move in opposite directionsl. This action steers the boat. Upon
shunting. the other arm on which the rocker arm is mounted must be released
from its lock and swung 180 degrees (plus or minus a few degrees) to its new
locking position. Notice the locks in the photos are spring loaded using a
bungy cord.
In explaination of the plus or minus a few degrees I will say that you might
find that while sailing along that you want to be able to have your foils
aimed upwind a few degrees of the centerline of the boat in order to allow
the hulls to travel straight through the water while the foils take a little
bight. Some boats are set up to have their boards 'jibe' when they tack for
the same purpose. On the other hand you might want to aim them off to
leeward a degree or two. Don't laugh. The surface water that the hull is
going through is traveling down wind and the water lower down that the
rudder or board is going through is stiller. Anyway, my rudders on my proa
are adjustable by simply loosening two wing nuts for each direction. I
haven't determined how to adjust them for optimum performance yet but I
think that it will not be just one position.
Regards,
Joe
Dean,
Sorry for the long explanation. I thought you were talking about the first
two pics or diagrams.
The levers of which you write are the locks for the arm to lock in. They are
spring loaded together using a bungy cord. Please notice the square end of
the arm protruding out from under the rocker arm. That end snaps into place
at the ends of its travels in the square notches on the sides of the levers,
one at a time of course. The thing in the middle is the pivoting end of the
arm. Under the swing end of the arm is a caster that supports the weight of
the arm. I hope this clears it up for you. If not please tell me. If you
are thinking of using it I might be able to help.
Regards,
Joe
Kevin O'Neill:
Joe
That's just beautiful. Very very clever, thanks for
showing it to us. Your solution is quite a bit more
elegant than mine is.
Are those Hobie 16 rudders and cases?
Kevin
Joe:
Thanks guys for the kind words. Those are indeed Hoby16 rudders that I
bought from a used sailboat hardware shop. The tiller version is not quite
fool proof yet but it works well if when you shunt, you bring the 'arm on
which the rocker is mounted' half way through its travel, then get the sail
around, then get the boat moving on the new shunt, then move the 'arm on
which the rocker is mounted' the rest of the way to its new lock-in
position, there is no problem. I only sailed it three times and I haven't
debugged it completely yet. I do believe that the original version (first
picture) should prove to be fool proof but I can't say for sure as I've
never tried it. Maybe some of you might.
I am in Portsmouth, Virginia USA which is on the Elizabeth river which flows
into the Chesapeake Bay which is ten miles away. I hope some of you are
near here but I don't know as I have never seen another proa in this area.
Where are y'all from?
Best regards,
Joe
Pictures follow, originally posted in Yahoo group proa_file Photos section. All pictures belong to Joe Creecy.
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