New Rudders for My X

[sailboatmike]

One of my high priority winter jobs is making some new rudders for my 1995 X

I still have the original horrible things and to say the steering is turn the wheel and hope would be an understatement,

That being said I have learnt to live with them somewhat and learnt to live with the constant stalling of the rudders, and backing off when she keep ploughing straight ahead instead of bringing her bow around.

So a few months ago one of the members sent kindly sent me an outline of the M rudders, for comparison.

Today I started the project, My original X rudders are hydrodynamically horrible, and certainly not NACA 12 foil design (thickness of 12% of chord length at 30% of the chord back from the leading edge)

Working off the M rudder template and pictures of the aftermarket performance rudders available for the X I have decided to narrow them down to 10 inches from the original 12 and increase the length by 6 inches. This gives me close to an additional 25% area, reducing the drag by going narrower from leading to trailing edge and increasing the efficiency by having the rudders deeper in the water that isnt disturbed and will give me the ability to build them to NACA 12 thickness.

Just for those geeks, the original rudders have a 12" chord )leading edge to trailing edge) so should be 12% of that thick at the thickest point, which would be around 36mm or 1 1/2" thick , yet the rudders are actually 1 1/8", I know whats 3/8? or 10mm between friends, but having them thinner is what would be used for high speed dinghies, in other words our 6Knts is just to slow for the rudder design, hence the constant stalling

[dlandersson]

You may want to look into the whole steering thing. I have the original 98X rudders, plus a spare set and they seem to work pretty well. I turn the wheel, the boat turns.

I still have the original horrible things and to say the steering is turn the wheel and hope would be an understatement,

[sailboatmike]

Originally before starting the process the steering was so bad it was dangerous, the channel I have to navigate to get in into open water is only about 25 meters wide, shared by other boats coming and going, boats moored on poles (bow and Stern) both sides that create a wall and generally a cross wind, lets just say getting down the channel wasnt a relaxing experience.

I went around the steering and took as much slack out of all the pivots as I could, this greatly improved the situation but you never feel the helm has real authority, it does come around slowly as long as you dont have too much rudder input, the motor helps turn I think more than the rudders.

Under sail with no motor being able to tack as low speed is problematic because you cant turn the rudders enough before they stall, so small inputs, of course that means it takes longer to cross the eye of the wind so you lose momentum going around or stall out and have to do a gybe instead of a tack after you back wind the jib to get out of irons. At speeds around 5 knts, just the mass of the boat gives you enough momentum to tack, not with great authority, but it does come around.

I realize that our boats are no nimble racers and to enter into a tacking duel would be ludicrous, but it is frustrating when you go for that extra bit of helm and she just plows straight ahead because the rudders have totally stalled and are now just creating drag.

On the positive side, the new template has been cut out and bow I have to go back down to the boat just to make sure I have clearance required to lift them without hitting somethibg

[dlandersson]

What shape are your old rudders and brackets in?

Thinking of selling them?

[sailboatmike]

Cost of sending them to the USA would be prohibitive, they are not light things as you know.

I will be reusing the original brackets, the will be strengthened of course, I have some nice 5mm Aluminium plate laying around which will make excellent bracing for the brackets

[Rick62]

looking forward to hearing about your results. Rudders a very important on boats
Keep up the good work!

[tp56ihs]

I just broke both of my 1996 26x rudder heads and was trying to decide what to do. My rudders was chewed up a little by the prop as well. (caught in a storm on Neuse river mouth). I was wondering if there are other options. Should I replace with same heads and repair rudders? Upgrade to stainless heads and new rudders? Or fabricate something new entirely like a Hake slide up and down system? Any opinion's?

http://www.windwager.com

[sailboatmike]

I have been using this page amongst many others for my info

http://www.paceship.org/how_to/rudder.asp#theory

After reading it you can see why the steering isnt as good as it could be