[Rhodes22-list] Curved Rudder | 84 Rhodes 22

[ROGER PIHLAJA]

Hi Chris,

There were a couple of very significant changes in that time period.  The IMF mainsail became available and very popular.  The centerboard was changed from the original high aspect ratio hydrofoil blade to the present “Diamond Board”.  Both changes would tend to increase weather helm.  I’m not convinced a few degrees of forward tilt on the rudder blade would fix these issues.  But, the rudder blade has a lot of wetted surface area to generate side force and its moment arm relative to the hull’s center of lateral resistance is several feet.  So, small changes in the rudder blade tilt angle might be noticeable in the weather helm/lee helm balance.

Two questions, do you have the IMF mainsail and do you have the Diamond Board?  S/V Dynamic Equilibrium has a conventional mainsail and the older style blade centerboard.  As my thesis advisor in grad school always admonished me, “Theory guides; but, the experiment decides.”  I can always be persuaded by good data.  Unfortunately, Sanford Lake is not scheduled to be refilled until the summer of 2024.  So, I don’t have a good venue to run this experiment.

Roger Pihlaja
S/V Dynamic Equilibrium 

Sent from my iPhone

> On Dec 4, 2022, at 4:47 PM, Chris on LBI <cknell at vt.edu> wrote:
> 
> Todd,
> 
> In thinking about it further, I'll probably not put a stop in place ... at least not for a full season. I still want to convince myself that any permanent change would be worthwhile. There is a lot of flexibility in using the up and down hauls to control the angle of the rudder.
> 
> Chris
>