New rudder

[sangria]

Hi guys, I have a jeanneau sangria that needed a new rudder. I am making a small alteration to it and would like your oppinion on how it can effect the
performance, handling. To put down the rudder it had to have a part of the rudder taken off and now i am leaving it without as you can see in picture. Its the bottom part under the end shaft. goo.gl/photos/YzqyHsD9hiP5HvW69 before the rudder used to go a few mm below the shaft end. Now im leaving the gap so it would be easier to remove. Do you think this will effect the manuverability? This is how it was before goo.gl/photos/ZyspxkhMLJonL9hu9

[Trevor]

Hello sangria,

I have tried to work out why that section needs to be removed to allow the rudder to be removed but cannot work it out. Having said that, I don't think the handling would be materially different without that section but I would be concerned that the leading edge is shaped correctly as the mould looks a little blunt to me. I think for minimum drag and consequently humming or vibration, the leading edge should be parabolic so I think the removal of that section will cause turbulence so its shape is important. I have added a couple of URLs that talk about that leading edge. It would be disappointing to launch the yacht, only to find that it has a nasty vibration or humming when sailed at a certain speed.

www.angelfire.com/tn/santana525/rudder.html

sagemarine.us/SCA_articles/SCA_pdf/smalltalk_55.pdf

Regards,

Trevor

[sangria]

Hi Trevor,

Thank you for getting back to me! The lower part had to be removed cause the lower bracket, where there is the end nylon bush, had to come out... I did check on other forums and yes, they also had to cut the rudder to get it out... strange I know... even more strange that the original Rudder was made of wood on a fibre glass boat... 

Here, this is a pic to understand more: 


drive.google.com/file/d/1lN-DTSkrgfUHsJBGLBRQ8N_GEpULPC2dGw/view?usp=sharing

About the leading edge, that is just the shape we took from the original one... the end product is coming out VERY smooth and neat.