Subject: Re: [harryproa] Re: Asymmetric Bi-directional Rudders Again
From: Dennis Cox
Date: 8/5/2010, 1:44 PM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

I'm not sure what they do on the Visionarry, but I will have the two controls set to independently control the rudders.  With these bi-directional rudders and their limited angle requirements, I'll switch to an aircraft joy stick mentality instead of a wheel.  I will make it so that you can put both sticks in your hand at once and they would articulate the rudders in opposite directions like Todd has going and thus get maximum turning rate.  Leaving the "forward" one vertical and using the one "closest" to you would only rotate the rudder aft of you.  I'm not sure how'd it feel, but shifting one stick one way and the other the opposite way would allow you to crab or set hull's AOA to zero for hopefully the maximum speed potential.
 
 

From: bjarthur123 <bjarthur123@yahoo.com>
To: harryproa@yahoogroups.com.au
Sent: Thu, August 5, 2010 11:28:25 AM
Subject: [harryproa] Re: Asymmetric Bi-directional Rudders Again

 



> You can do the same with twin rudders on a
> proa. You just need to be able to trim them relative to each other
> to minimise the overall drag on any point of sailing.

>It is VERY important to realise that they need to be able to have relative angle trimming.

there are two ways i see to do this: (1) have the two rudders independently controlled by two separate tillers/wheels. the helmsman would then statically fix the forward (or aft) rudder to counteract the leeway (locking it in position), and dynamically steer with the aft (or forward) one. or (2) the rudders could be linked together such that they countersteer, and the helmsman would have a separate control mechanism to adjust the average rudder angle for the leeway.

questions:

1. which is better in terms of performance?

2. visionarry and harry both have two wheels. do they just redundantly countersteer or do they control the rudders independently?

ben

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