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Reply to: Nacra 5.2 Rudders

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[quote=memphisnacra]First I shortened the tie by by an inch. I didn't have any more adjustment one direction. Fixed that problem. Then I re-drilled the pin holes in the tie bar ends to accept the next size up pins to have zero play. Now the tie bar to tiller arms are completely play free. Then I re-drilled out the gudgeon holes and the casting holes to 11mm with new 11mm shafts. Zero play in those now. Then I filled the pivot bolt holes in the blades. Then used a straight edge lined up with the gudgeon pin centerline and kicked the rudder 1 3/4 inches past the centerline at the furthest most point on the front edge of the blades. Aka just raking the blades under the boat more. Then redrilled the holes. Added the 2;1 system on the rudder down haul. Replaced the pivmatic cleat things with cam cleats or even less pulling the line back.

Now the boat always pulls to the right on any tack or wind condition. Lifting the port rudder completely fixes it. Lifting the starboard rudder changes nothing. With both rudders down I get BAD weather helm on starboard tack. BAD lee helm on port tack. But if you lift the port rudder the helm goes neutral. Lift the starboard rudder and you still have the same lee or weather helm. AKA the boat always pulls to the right. The toe adjustment was just set on the money about half way down the blades. The rake seems to be nearly identical. Oh and I also raked the mast back 2 holes on the forstay. I didnt notice any gains so I will put it back. But I can't imagine that is the issue.

Since then I have brought the port rudder back for close inspection. After looking very hard it looks like the rudder is cocked sideways in the casting in a manner that would make the boat always pull to the right. So I pulled the blade out of the casting. I put a long bolt in the pivot hole in the blade and just looking at it you could see majorly that the hole was not straight on both axis. As in looking from the top of the rudder down or looking from the back to the front. So I once again filled the hole and this time mocked up the rudder in my mill using levels and such. I re-drilled the hole absolutely perfect to the line where the two halfs of the blade where they are glassed together meet. Hard for me to explain but the hole is now dead on straight on both axis. So I bolted the blade back in the casting. Still looks cocked in the casting exactly the same. Now very frustrated I pulled the rudder back out again and looked at it against a black background and found that the two halfs of the rudder don't even match. The foils and shape to each freakin side are not even the same. So now I question how straight the casting or casting holes are.

Anyways. I discussed this for 4 hours with another expert today and decided upgraded rudders sounded pretty nice right about now :)[/quote]

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