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post #1 of Old 11-19-2010 Thread Starter
basssears
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Drop rudder design

Struggling a bit with rudder planning, curious on everyone's opinion.

I have a Nimble 20, current rudder fits the look of the boat nicely, but the "drop" is just a single sided slab of aluminum, which bangs and looks ugly. Want to keep the current rudder but upgrade the drop.

Here's the current rudder:
http://www.pictureofnectar.com/outside/stock_rudder.jpg

Plan #1:
http://www.pictureofnectar.com/outside/plan1.jpg
...was to be like the Meadowlark rudder, use cheek plates on each side of the main rudder attached to the drop. Problem with this is either they're huge cheek plates with lots of turbulent gap between the cheek plate and the drop rudder itself, or I move the pivot point all the way to the back of the main rudder, and I'm not sure how that would work performance wise?

Plan #2:
http://www.pictureofnectar.com/outside/plan2.jpg
...would be a piece of plywood on each side of the main rudder, but then solid (well, epoxied & screwed layers of) plywood at the bottom end, maybe with some strapping / flat bar aluminum or bronze for strength. The plus here is I can keep the pivot point farther forward so the drop rudder is in line with the rest of the rudder. But Iím not sure if that matters, and I'm not sure if design #2 would be strong enough with the two pieces of plywood on either side of the main rudder?

Most of the other Nimble rudders out there:
http://www.pictureofnectar.com/outsi...ble_rudder.jpg
... have a single piece of metal (prob. aluminum) sandwiched in the middle of the main rudder, but short of building a whole new rudder (which I don't really want to do) I don't see how I could gracefully cut a slit in the main rudder, get it sealed up again and then install a piece of metal in there.

Any / all opinions welcomed, as usual!

Thanks.

-- Bass
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