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New Rudder

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yjacket
Deckhand

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USA
7 Posts

Initially Posted - 03/19/2008 : 18:14:04

We just added a replacement rudder on Grace, a 1995 wb 250, and is it sweet. Still doing a little tweeking but the helm issues have all but gone away. Weather helm, just a tad, turn on a dime--you bet. Better off the wind as well. More to follow--Made by Blair Wind and Wood Boats, Clarkston Wa.

Edited by - on

Russ.Johnson
Commodore

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USA
855 Posts

Response Posted - 03/20/2008 : 11:42:02

Which rudder did you have before? Was it the 2nd generation kick-up rudder?

Yjacket, here is one of the pictures you sent me.
It appears your old rudder was a 2nd generation fixed rudder.
The new rudder looks much more balanced than the original.

Old rudder left, new rudder center, paper cutout of 3rd generation rudder right.
The paper cutout looks like the 3rd generation water-ballast rudder (5-feet).
The 3rd generation wing-keel rudder is about 6 feet.
The water-ballast rudder is shorter to match the depth of the centerboard in the raised position.

Edited by - Russ.Johnson on 03/25/2008 01:38:42

Dave Bristle
Master Marine Consultant

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Djibouti
10005 Posts

Response Posted - 03/20/2008 : 12:38:41

"A tad" of weather helm is just what you want--racing or cruising.

Edited by - on

PDXSteve
Deckhand

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20 Posts

Response Posted - 03/20/2008 : 12:48:03

Please add info on this rudder, thanks..photos, price, web site, etc. I've finally replaced my OB (now have a honda 9.9) and Im looking for a next gen. rudder before i work on my hard link set up.

Edited by - on

yjacket
Deckhand

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USA
7 Posts

Response Posted - 03/20/2008 : 18:34:58

[quote]Originally posted by Dave Bristle
 "A tad" of weather helm is just what you want--racing or cruising.
True, I have only had her out in 10 to 12, was great, want to go play in about 20 and see how she handles
More to follow--

Edited by - on

yjacket
Deckhand

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USA
7 Posts

Response Posted - 03/20/2008 : 18:47:45

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by PDXSteve
 Please add info on this rudder, thanks..photos, price, web site, etc. I've finally replaced my OB (now have a honda 9.9) and Im looking for a next gen. rudder before i work on my hard link set up.
<hr height="1" noshade id="quote"></blockquote id="quote">--- This rudder ran about $800 I will get some photos coming as well. Randys e-mail address is trijuanon@webtv.net-- More soon--

Edited by - on

jlannutti
Navigator

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USA
102 Posts

Response Posted - 03/21/2008 : 09:46:11

Yjacket, I have a '98 WB called, coincidentally, Gracie.
I suspect that we have an identical setup. I'm not sure what "generation" rudder I have.I too fight weather helm at 15 knots and up. Did you take your old rudder in, did they sail your boat before making you a new rudder, or was this a stock item. They do not appear to have website. I'd like to get as much info as possible before contacting them. I'm about 3000 miles away from them so it's not like I can just run it back to them if it's not right.

Edited by - on

willy
Captain

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USA
422 Posts

Response Posted - 03/21/2008 : 14:31:53

Joe,
If you are ahopping for Rudders, don't foget to also look at the IDA Kick-up. It dramatically reduced weather helm for me, and gave me the advantage of being able to motor through about 24" of water. Their latest version has gas struts!
Willy

http://www.idasailor.com/catalog/product_info.php?cPath=33&products_id=584

Edited by - on

JohnMD
Navigator

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USA
207 Posts

Response Posted - 03/21/2008 : 16:54:45

I agree about the IDA rudders. Got rid of almost all the weather helm and stays down all by itself due to the gas struts. The rudder will kick up if it hits something. The boat shown in the link is mine. I replaced a third generation 'balanced' rudder (balanced, yea right).

Edited by - on

bill bosworth
Navigator

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USA
172 Posts

Response Posted - 03/23/2008 : 06:35:34

An inexpensive modification that I made to my 3rd gen rudder was to add a wing to the base of the blade. This 1/4" lexan blade seems to effectively lengthen the blade giving it more grab on the water without increasing the helm. Some might like to give it a try before spending nearly $1000 for a new rudder. The cost for this fix including 3M 5200 adhesive to attach it to the end of the blade was about $10.00. The blade in the picture was made of 1/8" aluminum.

Bill c250wb #134 Serendipity
on beautiful Kerr Lake, N.C.

Edited by - on

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/23/2008 : 08:15:10

Bill,

Interesting rudder mod. What are your thoughts/observations in relation to drag?

Edited by - on

bill bosworth
Navigator

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USA
172 Posts

Response Posted - 03/24/2008 : 06:18:11

Don;
The wing is very thin, and is generally in line with the water flow. I can't detect much in the way of drag and feel that if the rudder is working more efficiently, requiring less rudder angle to keep the boat under control, that the drag should be considerably less. As I understand it, the 3rd gen rudder supplied for the WB boats are shorter by at least a foot than those supplied for the wing keel boats. I would guess that the drag from a short rudder blade with a wing would still be less than that of a longer rudder blade. I should point out that the wing is only about 8" X 14" it looks larger in the picture because of the angle.I haven't found the wing to cause any strange steering problems. I have switched between the 3rd gen rudder with the wing and to my 2nd generation rudder several times for comparison. Both my wife and I prefer the 3rd gen rudder with the wing. We both enjoy sailing with a bit of wind and heal and know that something more than the standard 3rd generation rudder is needed when the wind comes up. The boat will still round up on very high angles of heal, but no more so than any other fin keel boats that I have owned.

Bill
C250wb #134 Serendipity
on beautiful Kerr Lake, N.C.

Edited by - bill bosworth on 03/24/2008 06:21:46

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/24/2008 : 11:26:06

Bill,

The drag I'm mostly referring to is that caused by different pitch angles. For example, when motoring on my C25, the stern squats and the bow lifts. It would seem a wing on the rudder would be plowing through the water like a powerboat does before it jumps on plane. Since this force would be translated as either an up or down on the rudder, I doubt it would be felt as pressure on the tiller/wheel, but you may see added turbulence.

Edited by - on

John Russell
Master Marine Consultant

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USA
3444 Posts

Response Posted - 03/24/2008 : 15:25:13

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by dlucier
 Bill,

The drag I'm mostly referring to is that caused by different pitch angles. For example, when motoring on my C25, the stern squats and the bow lifts. It would seem a wing on the rudder would be plowing through the water like a powerboat does before it jumps on plane. Since this force would be translated as either an up or down on the rudder, I doubt it would be felt as pressure on the tiller/wheel, but you may see added turbulence.
<hr height="1" noshade id="quote"></blockquote id="quote"> I wonder if it would cause a kick-up rudder to kick-up?

Edited by - on

JohnP
Master Marine Consultant

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1520 Posts

Response Posted - 03/25/2008 : 08:35:48

Bill,

Interesting design with a wing! Modern racing rudders are curved at the front bottom to minimize the induced drag off the trailing edge of the tip. Adding the wing there would do the opposite, inducing more drag from the vortices swirling off these added surfaces. This could both slow the boat and add to rudder area and bite at high speeds.

Do you think the boat is easier to handle in a blow perhaps due to automatic braking? Interesting design for non-racers.

Edited by - on

Arlyn Stewart
Master Marine Consultant

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USA
2980 Posts

Response Posted - 03/26/2008 : 07:31:43

IMO the plate acts in several ways...

It eliminates the flow off the end of the rudder and thereby reduces rudder lift losses.

It eliminates vortice induced drag caused by end flow loss.

When heeling it compensates the depth loss of the heeled rudder with the now increasing vertical section of the wing.

When heeling it retards windage produced leeway especially important at the stern where the force is producing a weather helm inducing yaw.

I continue to use the 2nd generation beaching rudder because it is doing a great job and provides the forgiveness of a beaching rudder I want. If the 2nd ever fails, I do own the 3rd and will add the wing though I might initially make the wing wider, knowing that a circular power saw will cut the aluminum plate without problem so it can be trimmed smaller easily to dial it in.
<hr noshade size="1">
For the more technically interested. Many readers know that I've claimed that the 250 suffers a yaw force produced by its hull form when heeling excessively that is more pronounced that most sailboat designs. To provide good boat handling, this force has to be compensated for. One technique I proposed to do that was with stern mounted twin asymmetrical daggers so that when heeled, the windward dagger would lift from the water and its lift force then would be lost leaving the immersed dagger's lift force to counter the yaw force generated by heeling.

My point in raising that issue here is that it could also be done with the rudder wing. If the wing were given an asymmetrical lifting foil downward, when heeled that foil would lift to weather and counter the boats yaw forces.

Of course... stern mounted daggers with asymmetrical foils could be designed to only be put down in rougher conditions where their drag wouldn't be of consequence in lighter conditions whereas a foil on the winged rudder would be there always. I do agree with Bill, the 3rd rudder on the water ballast is considerably shorter than that on the wing keel, and therefore the rudder has less drag and I'm not sure that a foiled wing would have that large of drag issues compared to the benefits.

What I can say is that the 3rd short produces tremendous drag when it tries to counter the boats yaw forces. It has a very high lift foil section that does not stall easily and will continue to lift at very high angles of attack to the point of tremendous turbulence and drag.

Edited by - on

bill bosworth
Navigator

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USA
172 Posts

Response Posted - 03/28/2008 : 21:27:21

I don't know that pitch angle is a major consideration with the wing, as the boat sits fairly level in the water compared with the extreme pitch of a power boat. As far as vortex losses off the thin section of the wing, well, I'm no navel architect, and a test tank is out of the question so I think I'll have to leave that to you engineers.
The wing isn't my idea, I have a small cat boat which is a Bolger design that has a wing on a very shallow rudder. Even though that rudder blade is only about 10" deep it has excellent control over the boat, with no cavitation.

Bill C250wb #134 Serendipity
on beautiful Kerr Lake, N.C.

Edited by - on

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/29/2008 : 12:55:38

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bill bosworth
 I don't know that pitch angle is a major consideration with the wing, as the boat sits fairly level in the water compared with the extreme pitch of a power boat.<hr height="1" noshade id="quote"></blockquote id="quote">

I wasn't referring to the pitch angle as the boat just "sits" in the water. My boat too sits quite level in the water. I was referring to pitch angle under way. As my boat picks up speed, the bow lifts and the stern squats, changing the pitch angle.

Additionally, again when sailing, a boat is in constant motion, pitching up and down as it interacts with the seas. Now I'm not a physicist, but it would seem that a wing on a rudder would have to have some kind of effect as the rudder plunges up and down with the stern.

Edited by - on

bill bosworth
Navigator

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USA
172 Posts

Response Posted - 03/29/2008 : 22:09:04

Don;
I understand what you are saying, I don't feel that the axis of flow of the water past the rudder changes all that much in that plane. I would wonder if the angle of pitch was a problem, wouldn't it also be a problem for the wing on a keel? The pitch angle would be the same for the rudder and the keel.
Bill
c250wb #134 Serendipity
on Beautiful Kerr Lake, N.C.

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