[Rhodes22-list] how straight does a rudder need to be?

[Mary Lou Troy]

Happy New Year!

Can you all stand to think about our starboard turning boat again? (There 
is a quick recap below if you don't remember the issue)

We didn't get a chance to try any of the in-water tracking tests previously 
suggested but we've done a fair amount of measuring of the boat on the 
trailer. We can't detect any asymmetries in the hull but did come up with a 
slight asymmetry in the mounting of the gudgeons for the rudder. Our 
question is: is the variance enough and in the right direction to cause the 
boat to consistently want to turn to starboard? We don't want to "fix" it 
and have the boat turn more strongly to starboard.

The situation is that the upper gudgeon appears to be centered and the 
lower gudgeon is 5/16" off-center. This causes a slight slant to the 
rudder. The lower tip of the rudder is about 1" off of center. Is this 
enough to cause the observed turning to starboard?

Thanks again
Mary Lou
1991 R22  Fretless
Ft. Washington, PA /  Swan Creek, MD


Here's the summary of the posts from earlier this fall:

We've had lee helm issues with Fretless since we got her. The learning 
curve learning to sail her and the fluky wind and current conditions on the 
Chesapeake have slowed us down diagnosing the problem.

She has always sailed better on starboard than on port. When we set her up 
this spring we lengthened the forestay and took up the backstays. In a nice 
breeze with a full main and genoa this gave us a small amount of weather 
helm on starboard and less lee helm on port. It also made us really pay 
attention to the difference between her behavior on port and starboard.

Roger mentioned looking at how she sits on her lines and indeed she does 
have a slight list to starboard sitting in the slip (in spite of the 
outboard, 7 gallons of gas and the battery all stored to port. Bill Effros 
said he thought that if the boat was too heavy to port it would turn to 
starboard. These two thoughts seem to contradict each other but we'll work 
a bit more on her trim.

Bill & Slim mentioned heel as a contributor to weather helm but I think we 
heel about the same on port and starboard. Those fluky winds make it hard 
to tell.

Jim Connolly mentioned a similar port/starboard problem but then mentioned 
that he thought he had a spreader problem that might be contributing. As 
near as I can tell, our mast is straight and centered. We tune the rig with 
a Loos gauge and have measured with a halyard to the chainplates. We'll 
take a look at the spreaders though.

Lastly, Steve and Slim mentioned that maybe something was out of whack with 
the keel, the centerboard or the rudder. We've taken a look at those 
possibilities. There's nothing immediately visible with the keel or the 
rudder. The centerboard drops cleanly and does not bind or thump about 
significantly but we've never taken a really good look at it. Fretless has 
an unusual repair (?) to her centerboard trunk (there is a flat plate 
glassed over the forward part of the trunk - between the trunk and the 
centerboard cap) that prevents us from removing the centerboard in the 
usual fashion). Raising and lowering the centerboard has no effect on her 
tendency to want to turn to the right.