On 2008-08-13 15:10:20 -0400, Ryk said:

On Wed, 13 Aug 2008 12:12:52 GMT, in message
2008081308125316807-jerelull@maccom
Jere Lull wrote:

Yes size helps, but Xan's original rudder was scimitar-shaped with slab
sides and a center of effort about 10" behind the pintles. The rudder I
built had the same wetted surface, but was SO much better, very little
"helm" until we were well heeled.

I think the 28 rudder was the same shape as the original Tanzer 26
rudder, with the same problem. Did you build yours based on the T26
changes, or just common sense? I actually liked the load on the old
T26 rudder, as the main sheet in one hand (6:1) and the tiller in the
other balanced.

Ryk

Johanne Tanzer gave all his boats about the same rudder, so the problem
was endemic amongst the fleets.

When I built our replacement about 15 seasons back, I only had the T22
"new" class rudder and NACA 0012 foil as patterns, so I guess my answer
would be "common sense". The 26 rudder came later, as I recall. I
didn't move our leading edge forward in the first incarnation, so found
a need to re-do the blade to add balance. I screwed up the construction
at the time, so had problems with expansion and cracks most years since.

Just this spring, I finally got an IdaSailor blade. It's obviously a
relative to what I and Rik Hall created years back, closer to mine than
Rik's, as it happens, but I believe they built it too deep. I may chop
about a half foot off between seasons as we've more than necessary
authority.

While I could probably comfortably sail Xan with the old rudder for
short times in moderate conditions, my wife had difficulty pushing it
while we were motoring. It took a LOT of effort to push the tiller over
even when we were flat.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/