Association Forum - Rudder advice

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 250 Specific Forum

Rudder advice

New Topic

Topic Locked

Printer Friendly

Author

Topic

cmvitt
Deckhand

Member Avatar

USA
3 Posts

Initially Posted - 04/11/2007 : 23:06:10

Hello all,
I've been lurking on this wonderful forum for some time, and have read, with great interest, much of the advice, banter and opinions offered. I've recently joined the association and intend to partipate, from time to time, in these lively discussions.

On to the issue at hand...

I purchased a C250 WK (#521) over a year ago, and when purchased, it had an IDA balanced rudder. Overall, I liked the performance of the rudder -- being better balanced, it requires far less helm effort than the original, but at large heel angles, there is not much rudder in the water [it's about 3" shorter than the original], which I believe contributes to the chronic round-up problems I have w/ the boat...

A short time ago, while sailing off the N. California coast, in moderate conditions (20kt wind, 6' swell w/ 2' wind waves), with the main reefed and a 110 jib, I rounded up in a puff, and my IDA rudder broke in half, immediately below the lower pintle. This, of course, left me rudderless, 2 miles offshore and 5-6 miles away from harbor. Happily, I was able to fire up my outboard and struggle home using the outboard to steer (which was surprisingly difficult, by the way).
I contacted Joel at IDA (who said mine is the first IDA rudder to fail on a C250), and he has graciously offered to replace the rudder at his cost (as I was not the original purchaser). In talking to him, I explained that while I liked the performance of the rudder, my boat has the standard C250 round-up when heeled > 30 deg. problem, and he offered that if I wanted the rudder to be longer than the standard 68", he could build me a custom one that is longer (and therefore may work better at larger heel angles). Since I sail mostly in the San Francisco bay, where the wind is often 20-30kt, I would really like to address the round-up issues with my boat.
So, my question to this forum is: Is it a good idea to have IDA build me a custom, longer-than-the-keel rudder? Do you all think this would have the desired effect of reducing the liklihood and/or frequency of round-ups in breezy conditions?
Thanks in advance for any insight/advice.
--Craig.

Craig Vitt
Northern CA

"La Dolce Vita"
2001 C-250 WK #521

Edited by - cmvitt on 04/11/2007 23:54:35

John Russell
Master Marine Consultant

Members Avatar

USA
3444 Posts

Response Posted - 04/12/2007 : 10:56:24

Remember, my experience is based on what I've read, not what I've done. I'm a novice's novice.

Having said that, I was wondering if the issue isn't the length of the rudder but rather the degree of heel. From what I've come to understand, the efficiency of the hull (meaning, for this discussion, forward motion through the water) is dramatically reduced when heeled much beyond 20 to 25 degrees. At greater heel angles the rudder is trying to lift that 1900Lb chunk of lead out of the water rather than just move it side to side. In fact, this would contribute to rounding up since it is exerting very little lateral pressure.

I just raise this in the interest of learning from those that have REAL experience, not just "book-learnin".

Edited by - John Russell on 04/12/2007 10:59:22

AADIVER
Admiral

Members Avatar

USA
966 Posts

Response Posted - 04/12/2007 : 17:07:01

15 degree heal is about max for a 250. Beyond that, efficiency is gradually lost, i.e., no increase in hull speed. The WK 250 is a light air vessel.

Edited by - on

Turk
Admiral

Members Avatar

USA
736 Posts

Response Posted - 04/12/2007 : 17:40:11

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by FARMHAND
 15 degree heal is about max for a 250. Beyond that, efficiency is gradually lost, i.e., no increase in hull speed. The WK 250 is a light air vessel.
<hr height="1" noshade id="quote"></blockquote id="quote">

Ahh, but I would disagree! It may become more inefficient at higher heal angles but the increase in wind speed and keeping the sails up (no reefing now!) and extreme heal angle still makes for the faster boat. I prooved it time and time again every Monday night on the race course.

Edited by - on

Turk
Admiral

Members Avatar

USA
736 Posts

Response Posted - 04/12/2007 : 17:45:59

I did't mean to hijack the thread. I think the rudder is just fine. Maybe your boat isn't balanced. I had to add weight (two batteries and 12 gal of water) to the bow to get the boat to handle well in higher winds. I've been out in 20-30 and do not round up like most others. The weight improved the "feeling" of the boat tremendously. Have you tried the weight up front? The boat will point higher also.

Edited by - on

JohnMD
Navigator

Members Avatar

USA
207 Posts

Response Posted - 04/12/2007 : 19:05:39

I, too have problems with my 95 250WB rounding up when the boat heals over too far. You can tell from the tiller that the rudder has come out of the water when it happens. I too have wondered how a longer rudder would affect this. I don't understand the weight in the bow thing. Could you please explain how pushing the bow down further into the water with more weight forward helps keep the rudder from coming out of the water. Seems, if anything, it would cause just the opposite. Thanks

Edited by - on

Arlyn Stewart
Master Marine Consultant

Members Avatar

USA
2980 Posts

Response Posted - 04/12/2007 : 19:30:05

To consider commissioning the build of a longer rudder, I'd want to know what the builder plans to do differently to strengthen the rudder. High aspect ratio rudders enjoy better lift to drag ratios than does the stock Catalina rudder but making a high aspect ratio rudder strong requires greater design and construction considerations.

Which stock rudder are you referring to? Can you give us its measurements? Do you have this rudder also or were you passing on the perspective of the PO.

I was thinking your hull number should have had a 3rd generation long and that wing keel owners were pretty happy with those as they are reasonably balanced and provide fair control.

Do you have wheel steering... if so... it plays big into the helm issue and further comments will help you.

Those who suggest trimming the boat on her lines are correct. If the boot stripe shows a stern down pitch, then it can contribute to weather helm on the 250... this goes against most weather helm theory, but relates to the 250 design.

Edited by - on

cmvitt
Deckhand

Members Avatar

USA
3 Posts

Response Posted - 04/12/2007 : 21:35:10

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Turk
 Maybe your boat isn't balanced. I had to add weight (two batteries and 12 gal of water) to the bow to get the boat to handle well in higher winds.
<hr height="1" noshade id="quote"></blockquote id="quote">
I have a large group 31 battery installed under the V-Berth, along with a 50# bag of sand. That seems to put her on level lines in the water. And the boat does handle well in up to 20kts or so -- higher gusts and/or heel angles in excess of ~30 deg. will cause a round-up nearly every time. Of course, in higher-wind conditions, the wind-waves also become a factor. My thinking was that with more rudder in the water, I would have better control and that may reduce the round-up tendency.
Anyone have thoughts on this notion?

Edited by - on

cmvitt
Deckhand

Members Avatar

USA
3 Posts

Response Posted - 04/12/2007 : 21:47:35

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Arlyn Stewart
 Which stock rudder are you referring to? Can you give us its measurements?
... Do you have wheel steering...
<hr height="1" noshade id="quote"></blockquote id="quote">
The "stock" rudder is on my boat currently (having broken the Ida rudder). Having sailed a fair amount now with both, I can attest to the fact that the Ida required far less helm effort (and was therefore, I assume, much better balanced). The length of the (broken) Ida is 68" (it's sitting in my backyard). I believe the factory rudder is about the same length, but I don't have the exact measurement at the moment (as it's on my boat in the marina).

I do have wheel steering (with the pull-pull style setup, on which I have other issues -- an entirely different topic).

Your comments about the strength of the longer rudder is one of my concerns -- I broke the 68" version; presumably, a 74" variant will be even more so inclined. Another concern is that a longer rudder will likely extend below the keel. Obviously, should I run aground, damage to the rudder would be likely. Beyond that, is there any other technical reason that this is a bad combination?

Thanks again for all your feedback & advice. Much appreciated!

Edited by - on

Arlyn Stewart
Master Marine Consultant

Members Avatar

USA
2980 Posts

Response Posted - 04/13/2007 : 06:44:41

Craig... The stock rudder on your boat should be the 3rd generation long which has been satisfying wing keel owners except for some cracking around the pintles.

The wheel steering used on the C250 is a small boat kit but unfortunately the 250 is a little hard mouthed and requires a large rudder for her size to hold control. This large rudder exceeds the abilities torque wise of the small boat design when sailing aggressive venues as yours.

The solution is to increase the wheel/rudder leverage ratio, which can easily be done by changing the pull/pull cables to open wires and the addition of an arc compensated steering arm extension. The extension doubles the wheel rudder ratio providing the leverage the wheel needs to handle the large rudder.

The conversion also solves the play and drag issues associated with the sheethed cables as well as the jumping of chain on the wheel cog that has been noted on pull/pull systems when sailing aggressive venues.

The conversion would allow staying with the Catalina rudder and be both cheaper and provide a better helm outcome. The conversion is also fairly easy to install.

http://www.stewartfam.net/arlyn/steeringkit.html

Edited by - Arlyn Stewart on 04/13/2007 06:51:43

JohnMD
Navigator

Members Avatar

USA
207 Posts

Response Posted - 04/13/2007 : 15:08:06

Craig, since I have the same problem and can understand how annoying it is to have a boat rounding up all the time, if it was me, I would have the guy at Ida make a longer runner and see what happens. He sounds like a real 'stand up' guy and I'm sure if it doesn't work he'll take care of it. I don't know him and have never done business with him, but, if he's offering to make a rudder for you at cost that says a lot. If you put the same rudder back on the boat you're guaranteed to get the same performance as you had before. That's my very cheap opinion. If you do get a longer rudder, please put a note out here and let us know how it works.

Edited by - on

bear
Admiral

Members Avatar

USA
909 Posts

Response Posted - 04/13/2007 : 15:56:09

Craig, Was that a beaching rudder? I was thinking if it wasn't a beaching rudder perhaps the PO hit something and started the cracking process. I have a WB with the last IDA beaching rudder made in the current configuration. Can't get rid of cold weather and snow to get 'Brandy" ready to go with the new rudder. That is one tough looking, HEAVY rudder. With "Brandy" on the trailer and the IDA rudder installed there's like 3" of clearance between bottom of trailer and ground. Good luck with your workings with IDA rudder
folks.

Edited by - on

Arlyn Stewart
Master Marine Consultant

Members Avatar

USA
2980 Posts

Response Posted - 04/13/2007 : 19:47:38

Re-reading Craig's post, he noted that the IDA rudder is a few inches shorter than the Catalina and that it has less control than the Catalina but also suffers less torque issues.

He notes this is likely due to better balance but I'd suggest that it more likely is do simply to having less lift (control) ability than the Catalina. Though I've not seen an IDA rudder, I believe they are advertised to be a high aspect ratio rudder (longer and thinner and having a fairly narrow chord). On the other hand the Catalina 3rd generation rudder has a fairly thick cross section and a fairly wide chord. It is designed to have a lot of lift (control) and given that the balancing act can only be taken to a given point... it is well balanced for the control it is capable of. If anything, my first outing with the 3rd generation rudder left me thinking it was balanced at the limit... this based on a very slight tendency to zoom. Zooming is when a control surface is overbalanced and won't hold a center position when hands offs.

This perception is based on old Hobie 18 experience... it having adjustable balancing rudders. Each of the two rudders had set screws to dial in the desired balance. They could of course be lowered one at a time to check individually but if going only slightly too far, the rudders would overbalance and the helm would not hold a center position but constantly try to pull the helm to the rudder stop.

I've digressed here a little but felt it was important to make the point that it is my belief that Catalina has balanced the 3rd close to its limits and that the torque suffered with it is mostly because of the high degree of control it provides.

What I'm saying is that if IDA produced a rudder with similar control to the Catalina, it would likely have a similar amount of torque as they have to live with the same overbalancing numbers as any other rudder designer.

It is not my purpose here to defend Catalina... those who have followed my rudder rantings know that I've been quite critical of Catalina for dropping the 2nd generation beaching rudder for the water ballast model. It was a very long high aspect ratio rudder capable of a great deal of control and was very deep... it hit the ground well aft of the boat when on the trailer (water ballast) so is capable of maximum control when sailing very aggressive venues.

The bottom line is that when a 250 is equipped with a rudder capable of providing the control needed for aggressive conditions, the stock wheel steering has inadequate leverage. The primary purpose of wheel steering on sailboats is to provide more leverage than is possible with a tiller... and it seems that the small boat system on the 250 is experiencing more torque rather than less. This can be corrected by extending the rudder arm... but unfortunately that can't be done without some form of arc compensation.

Arc compensation is observed on almost all wheel steering systems. It allows the cables to remain at the same tension throughout the rudder swing and allows the wheel/rudder ratio to be chosen to provide the needed power for a given rudder. The Edson Small Boat system does not employ arc compensation and thus the lever arm cannot be increased without incurring greater play at center rudder bringing the risk of increasing possibilities of chain jump on the wheel sprocket.

The conversion modifies the system to provide arc compensation and doubling the steering ratio. These changes turn the wheel into what it should be... a lever arm with more capability than a tiller, not less.

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.