Wednesday, February 29, 2012

New Rudder

After many years and different incarnations of kick-up rudders, I've changed to a variation of the cassette dagger rudder.  Thanks to Michael Storer, and the people he got it from, for the inspiration.
My chief complaint of my pivoting kick-up rudders was the difficulty steering when it partially kicked up.  I had a locking pin to use in known deep water but that is still not ideal.  Shallow water control was impossible.
The cassette I built has an open back with two wraps of bungy cord.  Initial sailing trials show it to be rock solid, but I have yet to see how it does over ten knots.  At most, I'll have to add extra bungy.
Besides being able to set the rudder depth for good shallow water control, it also kicks up in either direction for those times when you have difficulty getting launched off a windy lee shore.

7 comments:

Jim Finch said...

I really like this, maybe a similar concept could be used for daggerboard, too. Would you mind commenting on your rudder hardware? Thanks.

Wade Tarzia said...

Nice idea. I'm thinking of going back to a quarter rudder. How long is that blade? It looks very long, but maybe that is ther wide-angle lens? --Wade

Anonymous said...

Looks like a really good option for a Proa where you want to leave both rudders down a lot of the time. Hoe hard is it to haul the blade up and down?

Tom

Gary.Dierking said...

The hardware is standard off the shelf parts with a piece of 5/16" SS rod through everything. See the new photo.
The blade is 44" long and 8" wide, 0012 section.
You need to be leaning right over the blade to pull up or push down. I'm thinking about carving a polyethylene car that would slide up and down the aft edge of the rudder with the bungy passing over it. That would make the sliding easier and save wear on the bungy.

Rotorhead said...

Gary- My concerns with a cassette vice kick-up are for when I'm tooling around the shallows - if I go over a coral head or shallow rock, my kick-up will kick-up, where with a cassette, something's gotta give. Would the bungee stays give before the rest of the hardware?
-RH

Gary.Dierking said...

This is an open backed cassette and it kicks up like any other kick-up type. The bungy stretches as the blade goes back 45 degrees or so and it snaps right back to vertical after you've passed over that sandbar or coral head, unlike a conventional kick-up that requires user input to get it back down.
Michael Storer swears by them and they've been in use like 40 years down here.

Skip Johnson said...

The polyethylene block worked very well for me on two different setups was actually better on a bidirectional rudder, less of a sharp edge for the block to bite into. a detail; it helps to have some sort of stop on the back of the rudder that keeps the block from sliding higher on the rudder in a fully extended kick up situation. If not the block has a tendency to slide higher on the back of the rudder requiring a little manual push to get bungie back down, at least in the geometry I was using.