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Rudder support

PostPosted: Fri Jul 30, 2010 12:26 am
by Bigjake
Is a support/hinge at the bottom of the skeg allowed by the rules? I couldn't find anything about it.

PostPosted: Fri Jul 30, 2010 11:29 am
by Rick West
I am not clear to where you mean. A "skeg" is a fin or unmovable part of the keel. The extention of the keel where the rudder shaft enters the hull is call the princess fairing. The straight drop down the keel where the leading edge of the rudder meets the keel is the rudder fairing. These are terms passed down in our history.

The rudder is supported by the shaft as it passes into the hull and secured as shown on the building site. Some have placed a strut over this shaft and glued it to the hull. This shaft also extends down into the rudder about 60% and angles aft at 60-45 degrees. This stabilizes the rudder and prevents slippage.

Older boats do not have the half round fairing that envelopes the leading edge of the rudder. This can be made and has on many older boats till builders worked this into the hull mold. I have never seen a supporting hinge for the rudder on the EC12.


...94 [8D]

PostPosted: Fri Jul 30, 2010 12:09 pm
by s vernon
I think he meant on the bottom of the rudder - like on a Newport 12.

Scott

PostPosted: Fri Jul 30, 2010 1:48 pm
by Bigjake
Thank you, S Vernon. That is excatly what I mean - a support for the bottom of the rudder.

PostPosted: Sun Aug 08, 2010 11:02 am
by Bigjake
So nobody has an opinion? Ideas?

PostPosted: Sun Aug 08, 2010 11:10 am
by Rick West
I think the ideas were sorted out some time ago, Jake. I have not seen any fastener at the base of the rudder on the 12. I personal see no need. Damage to the rudder alignment has been rare and distortion in the water to pressure not suspected.

...94 [8D]

PostPosted: Sun Aug 08, 2010 11:12 am
by s vernon
My opinion is to look at every single racing EC-12 that has ever been built and realize that it is probably illegal to put a plate and a pin at the bottom of the rudder whether you can determine what rule outlaws that or you cannot determine what rule specifically outlaws that.

Scott

PostPosted: Sun Aug 08, 2010 12:57 pm
by Columbia
I don't see anything in the rules that addresses your question so my opinion is that it is legal. I don't see the need but then again you might be on to something. Either way I say knock yourself out. I like to see other people's approach to the EC 12 as long as they are withing the rules and spirit.

Joe

PostPosted: Sun Aug 08, 2010 7:27 pm
by RMDJBD
As a Hull manufacturer, and tinkerer, I have looked into doing a lower rudder support bearing but can not design one that does not interfear with Rule 3.3 or 7.3 and 7.4.

I find no need for a lower support if the upper support bracket is installed correctly and a properly sized shaft, I build my rudders with 3/16 S/S shafts.

Bob Dudinsky
R.M.D.MARINE

PostPosted: Mon Aug 09, 2010 12:20 am
by Bigjake
Bob, I have a design that conforms to the requirements of the rules. In my design, an aluminum tube will be used as a rudder shaft. Because there won't be any bending on the upper (present location) support, it will be a simpler and lighter installation without all the beefing up which is needed today. The lower support will not protrude below or to the siade of the existing shape of the hull or rudder.

The whole thing started when, as a retired aerospace design engineer, I looked at the EC12 drawing and didn't like the rudder installation (it doesn't make sense having such a long, tall rudder cantilever abaft a parallel, full height and beefy keel.)

Having said that, as a novice to the class I am not going to argue with experience and will go (this time...) the "traditional way" with a 3/16 SS shaft and cantilever rudder... I want to sail, not build boats!

PostPosted: Wed Oct 27, 2010 6:20 pm
by James L. Pardee
I have been running a bottom bearing on my 40 year old boat(the hull came from Buddy Blacks original mold)for years.

Rule7.3 states: "The rudder can not be thicker than the widest portion of the aft section of the keel."

This (to me) infers the rudder width, from top to bottom, can be as wide as the widest portion of the aft section of the keel.

Rule 3.4 states: "Notwithstanding rule 3.3, the aft edges of the keel may be faired into the rudder."

This (to me) infers that the aft edges of the keel can be faired into a rudder who's cross section (at the vertical center line of rudder shaft) is, in effect, a rectangle who's width is, as wide as the widest portion of the aft section of the keel.

Therefore; It is my opinion that a bottom bearing can be installed, legally,and it will make your EC 12 a more bullet proof boat at the expense of the added work and thinking you might require to accomplish this desirable feature. [:)]

JLP

PostPosted: Wed Oct 27, 2010 8:20 pm
by greerdr
And he always fast.
This skipper and his boat will give you a run EVERY time.
But I agree that we protect the rudder in transport and at rest, so it is an added item unlikely to add speed or much over what we have in insuring rudder alignment by using RMD rudder & shaft.

R.C.Greer