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As a sketch approximating the shape of the real graph provided by Climenuts, I would say it was true on this planet. Closer to a flat plate though, which has the apex of the lift curve around 10 degrees AOA, not 4 degrees. Also, the drag curve inflection should be in the vicinity of the lift curve apex. It's a sketch, not an engineering figure from which you extract design information. Have you never done a quick sketch to illustrate a principle? Why am I defending 10th tonner, anyway?

1 hour ago, El Boracho said:

That is true on what planet?

 

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Could be sail trim or bagged out old sails too. What's the mast rake like too? 

What ever happened to the notion that a rudder does nothing but add drag?  I know- take it to DA-   

A little weather helm actually is faster! At about 3 to 5 degrees rudder angle, the increased drag is more than compensated for by sailing higher, so there’s your best VMG. Boats that are absolutely n

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On 7/28/2020 at 3:22 PM, Renegade-27 said:

Already in progress :D

It would be nice if the prospective buyer doesn't experience a round up during the test sail, so fixing the problem is still important.

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7 hours ago, climenuts said:

Yes because 7° angle of attack on a rudder is completely stalled and generates zero lift.... Save some trees next time and just google an chart that's actually accurate?

Sorry that was a quickie. Of course the drag curve turns horizontal at 90 degrees, not 7. 

7 hours ago, climenuts said:

image.png.ee19fbe01f75322a89b061cfadd2616e.png

What actually matters is the ratio between lift and drag (C_L / C_D) which is greater at very low (3-7°) angles of attack translating to a good amount of lift with very little trade off for drag.

That’s the point I wanted to make. 

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5 hours ago, Shu said:

As a sketch approximating the shape of the real graph provided by Climenuts, I would say it was true on this planet.

Typical foils on this planet produce lift in both air and water until at least 15 degrees or more. That should be obvious to anyone who has steered a dinghy. On a rudder the drag coefficient obviously increases steadily until 90 degrees then declines back towards zero in a never-never land sometimes explored during a dial-up. Only horizontal at zero.

The @10thTonner is sketch is very misleading in its axes labels, and plotted values. Otherwise all well and good.:unsure:

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After quickly going through most of the posts I would have to agree with European bloke and zonker and several others that basically say DUMP THE MAIN , sailing and particularly racing is mostly about efficiency and if the boat wants to lay down it means you’ve gone past the Boats efficient ability to go in that direction,a bigger rudder might hold longer but you’d probably be no faster, I would suggest that you try to get yourself to be more efficient at your ability to use the maximum that your boat can give you, I would suggest that you could get perhaps a Santana 20 for much cheaper than any rudder modification and spend some time sailing the little Santana, a great boat, but will demand very close husbandry of the tiller and sail controls both upwind and especially downwind or you will be on your ear really quick, but after sailing one of those weapons your big boat is going to feel like a tank and will allow you more time to make the trim and steering adjustments that will make your sailing more efficient and hence hopefully quicker and the plus would be you could use the money saved by not modifying the rudder and blow the wad on new sails, good luck.

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10 hours ago, 10thTonner said:

Sorry that was a quickie. Of course the drag curve turns horizontal at 90 degrees, not 7. 

That’s the point I wanted to make. 

Sail trim is also very similar although the actual values vary quite a bit. It's why maximizing lift on the sails isn't fast; you want to maximize the ratio between lift and drag by feathering up a bit and having the inside telltales starting to lift.

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Not intending to lecture, but to share my experience.  I own a 1989 Olson 34, having bought it from the original owner in 2009.  The boat tends to round to weather when she starts to heel.  A feeling I was not accustomed to from my earlier experience.  I also found that the boat would rebound up significantly when flying a chute while strapped in tight, again , more than I was accustomed to.  After finding some water intrusion into my rudder, I decided to replace it vs repair.

I contacted the folks at Foss Foam , the original rudder manufacturer in Newport Beach CA.  They have several options that would work for my boat, I settled on a Carl Schumacher high aspect ratio rudder that is 6” longer than the original eliptical design.  

Fitting it on the boat helped significantly with round ups, and increased rudder efficiency as the boat begins to heel.  With the chute strapped, I can pump the rudder and have assurance that I can avert a round up.  I’m extremely happy with the rudders performance over the past 7 years.

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41 minutes ago, Peenstone said:

I contacted the folks at Foss Foam , the original rudder manufacturer in Newport Beach CA.  They have several options that would work for my boat, I settled on a Carl Schumacher high aspect ratio rudder that is 6” longer than the original eliptical design.  

Fitting it on the boat helped significantly with round ups, and increased rudder efficiency as the boat begins to heel.  With the chute strapped, I can pump the rudder and have assurance that I can avert a round up.  I’m extremely happy with the rudders performance over the past 7 years.

I have a 1983 Olson 40, with a Foss Foam rudder for an IMX 38: deeper, elliptical. Its an excellent rudder, but a bit too heavy on the helm, as it is not balanced enough. Never stalls. At about 20 degrees of helm, the power is awesome, nobody loses control. Normal sailing and surfing in up to 20 knots, 10 degrees rudder is rarely needed upwind or down, usually 5 degrees which is a pretty sweet spot in most foils: it is about the same as the leeway.

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On 7/28/2020 at 8:48 AM, astro said:

Bullshit.

Driving around with the brake on is faster you say.  Mmmmm

The fastest VMG is when the boat is balanced on both foils.  But you go with 5 degrees, I'll drive over the top of you.

you can say it's bullshit if you want. Farr did extensive tank and two-boat testing with AC sister ships and found that setting the rig for around 4 degrees weather helm was worth somewhere between .25 and .5 knots of boat speed. Until that time, everyone was setting up for neutral helm. 4 degrees of rudder is hardly a brake. 

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6 minutes ago, ryley said:

Farr did extensive tank and two-boat testing with AC sister ships and found that setting the rig for around 4 degrees weather helm was worth somewhere between .25 and .5 knots of boat speed. Until that time, everyone was setting up for neutral helm. 4 degrees of rudder is hardly a brake.

Kame Richards (Pineapple Sails) told me that the SF Express 37 fleet did a similar experiment and also found that setting up for some weather helm (by raking the mast aft) made for a faster boat that pointed higher.

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3 hours ago, Peenstone said:

Not intending to lecture, but to share my experience.  I own a 1989 Olson 34, having bought it from the original owner in 2009.  The boat tends to round to weather when she starts to heel.  A feeling I was not accustomed to from my earlier experience.  I also found that the boat would rebound up significantly when flying a chute while strapped in tight, again , more than I was accustomed to.  After finding some water intrusion into my rudder, I decided to replace it vs repair.

I contacted the folks at Foss Foam , the original rudder manufacturer in Newport Beach CA.  They have several options that would work for my boat, I settled on a Carl Schumacher high aspect ratio rudder that is 6” longer than the original eliptical design.  

Fitting it on the boat helped significantly with round ups, and increased rudder efficiency as the boat begins to heel.  With the chute strapped, I can pump the rudder and have assurance that I can avert a round up.  I’m extremely happy with the rudders performance over the past 7 years.

Foss Foam ( http://www.boatrudder.com/index.htm  ) and Foss Rudders ( http://fossrudders.com/  )appear to have the same name but are different companies.

and then FInco who has a partnership with Foss Foam http://www.fincofab.com/about.php

We used to buy replacement rudders for lots of Catalina boats from Finco.

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1 hour ago, Meat Wad said:

Foss Foam ( http://www.boatrudder.com/index.htm  ) and Foss Rudders ( http://fossrudders.com/  )appear to have the same name but are different companies.

and then FInco who has a partnership with Foss Foam http://www.fincofab.com/about.php

We used to buy replacement rudders for lots of Catalina boats from Finco.

Foss Ruddder and Foss Foam are the same guy. Rudders are built at Finco.

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Ryley has the talking stick... The Farr office did the most work, and we should note that their rudders are generally around 55% of the keel area. Rudder operating at around twice the effective angle (leeway plus helm) as the keel foil. So, and this will surprise many, the rudder generates almost half the sideforce, sailing upwind.

The reason it is faster is that the hull generates sideforce very inefficiently, around 4 times the drag per unit of lift, compared to the foils.

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Froggy:

Interesting info on rudder's contribution to lift. I thought as much. You have to take advantage of that lift.  Reminds me of a few years back when a Seattle racer of considerable success, bought a new Farr design, a 38'er, FARROUT, as I recall. He came to my office early in the season complaining about the balance of the boat, "Too much weather helm!" I suggested he contact the Farr office and get some specs on how to tune the boat. He did and that did not help, "Too much helm pressure!" I did not know what to do. I did not feel I could contradict what the Farr office was telling him re: the tune of the rig. I figured their advice was gospel. Then the racing started and started winning. I never saw him again.

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Bob,

Thanks for that. Bruce Farr very hot on optimising the balance and the foil areas..... scraping away the keel area so the boats were fast reaching and downhill, maximising the rudder area so you could press hard as well.

He would say that the design commenced from a big enough rudder for rough water downwind, back in the ims era.

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Nothing like smart ideas backed by data and real world success. I guess the thought experiment goes like this:

We’re sailing so must have leeway due to the force of the sails

Pushing the boat sideways is very lossy

A good foil works well up to 6 or 8 degrees 

As long as the keel is attached to the boat (not jibing) then you can only run it at 3 or 4 degrees 

Putting more lift on the rudder is fast

Thanks Guys

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On 7/29/2020 at 12:03 AM, 12 metre said:

Except...

Sails create an applied (active) force while the keel generates a reactive force

A resultant force is a single force that applies the same effect as the original system of applied forces.

At constant velocity, the active and reactive forces cancel each other out (i.e. Sum of Active - Sum of Reactive = 0)

In that state, side force (sails) and lift (keel) are equal and opposite.  Same thing with drive (sails) and drag (all sources).

I won't get into the torque balancing.

Now I'm torqued off.  Actually lots of great talk here. The weather helm thing is great for those who cannot drive a balanced boat. I love getting the boat in the zone and all I have to do is hold the tiller, compensating only for waves.

Here is a shot of us dusting an sc27. Notice the angles. This was an incredible windward leg, in the zone. My mate Kim from Perth trimming. I trust him and he trust me. That helps heaps

2020-06-09.jpg

2020-06-09.jpg

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2 hours ago, Meat Wad said:

Now I'm torqued off.  Actually lots of great talk here. The weather helm thing is great for those who cannot drive a balanced boat. I love getting the boat in the zone and all I have to do is hold the tiller, compensating only for waves.

Here is a shot of us dusting an sc27. Notice the angles. This was an incredible windward leg, in the zone. My mate Kim from Perth trimming. I trust him and he trust me. That helps heaps

2020-06-09.jpg

2020-06-09.jpg

You’re pinching.

 

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On 7/31/2020 at 7:30 AM, Bob Perry said:

Froggy:

Interesting info on rudder's contribution to lift. I thought as much. You have to take advantage of that lift.  Reminds me of a few years back when a Seattle racer of considerable success, bought a new Farr design, a 38'er, FARROUT, as I recall. He came to my office early in the season complaining about the balance of the boat, "Too much weather helm!" I suggested he contact the Farr office and get some specs on how to tune the boat. He did and that did not help, "Too much helm pressure!" I did not know what to do. I did not feel I could contradict what the Farr office was telling him re: the tune of the rig. I figured their advice was gospel. Then the racing started and started winning. I never saw him again.

How the rudder is balanced, as in how far forward the rudder post is in the foil, has a big effect on the feel. My guess is the rudder on that boat has the post near the front of the foil. He was just bitching about the pull on the tiller but he was probably only holding about 4-5 degrees of weather helm. 

 

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21 hours ago, Peenstone said:

You’re pinching.

 

21 hours ago, 12 metre said:

Or shooting the mark.

20 hours ago, Peenstone said:

Maybe , but not "in the zone". 

Boy, you see 2 boat lengths and I guess you know the whole weather leg? That is what is wrong with these forums you think you know what happened by one photo.
 

Unfortunately you were not there and I was and these are the only photos taken by the mark boat.

Hey Pee head, I got a zone for ya right here.

 

 

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3 hours ago, Mark K said:

How the rudder is balanced, as in how far forward the rudder post is in the foil, has a big effect on the feel. My guess is the rudder on that boat has the post near the front of the foil. He was just bitching about the pull on the tiller but he was probably only holding about 4-5 degrees of weather helm. 

 

Farr has designed some of the best and most "driveable" rudders on production boats, e.g. the Farr 39 and Farr 40 design types of the mid-'90s to mid '00s.  Fairly deep, moderately short chord length, forgiving NACA section and about a 7:1 balance between the front and back of the shaft centerline.  They do have a fairly solid feel of two or so pounds of "tug" when you are set up for good upwind performance, I've found.  And they grip exceptionally well under reaching loads and give you a decent bit of notice before they stall out.  

Nothing wrong or very extreme about this rudder.  Looks decently balanced as well.

Screen Shot 2020-08-01 at 3.25.06 PM.png

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18 hours ago, Left Shift said:

Farr has designed some of the best and most "driveable" rudders on production boats, e.g. the Farr 39 and Farr 40 design types of the mid-'90s to mid '00s.  Fairly deep, moderately short chord length, forgiving NACA section and about a 7:1 balance between the front and back of the shaft centerline.  They do have a fairly solid feel of two or so pounds of "tug" when you are set up for good upwind performance, I've found.  And they grip exceptionally well under reaching loads and give you a decent bit of notice before they stall out.  

Nothing wrong or very extreme about this rudder.  Looks decently balanced as well.

Screen Shot 2020-08-01 at 3.25.06 PM.png

7:1 would place the post near the front.  NTTAWWT. 

  As to the OP, I encountered an old IOR-ish boat once, a NY 36, which had that same really irritating heavy weather helm and when it blew hard the complaint was the damn thing would almost auto-tack on him in the low 20's degree of heel. I looked up the main and it was a deep cut and blown, the draft was now well aft of 50%.  

 A new main fixed the issue. Everybody knows sail trim drastically affects helm, but in some boats sail shape does too. 

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1 hour ago, Mark K said:

7:1 would place the post near the front.  NTTAWWT. 

  As to the OP, I encountered an old IOR-ish boat once, a NY 36, which had that same really irritating heavy weather helm and when it blew hard the complaint was the damn thing would almost auto-tack on him in the low 20's degree of heel. I looked up the main and it was a deep cut and blown, the draft was now well aft of 50%.  

 A new main fixed the issue. Everybody knows sail trim drastically affects helm, but in some boats sail shape does too. 

Actually, that's the point.  The balancing portion of the rudder wants to be at the front.  Perhaps logically I should have said 1:7 if the boat is assumed to be heading toward the left side of the page. 

The 1:7 is just a target number that I found by talking with Britt Chance when rebuilding a damaged spade rudder on a race boat.  Seemed to work fine on a couple of trips to Hawaii.  My Farr boats have had very much the same balance proportion by eye, but I've never calculated it.

https://www.sciencedirect.com/topics/engineering/balanced-rudder

(Author is not a fan of the semi-balanced skeg rudder.)

And of course sail plan, sail trim and shape, rig rake and hull shape have easily as much or more to do with helm balance.  I'm always amazed that a 1" -2" drop of a traveler on a well-set up 50'er can change the helm angle by a couple of degrees or the feel by a couple of pounds of pull.

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45 minutes ago, Left Shift said:

Actually, that's the point.  The balancing portion of the rudder wants to be at the front.  Perhaps logically I should have said 1:7 if the boat is assumed to be heading toward the left side of the page. 

The 1:7 is just a target number that I found by talking with Britt Chance when rebuilding a damaged spade rudder on a race boat.  Seemed to work fine on a couple of trips to Hawaii.  My Farr boats have had very much the same balance proportion by eye, but I've never calculated it.

https://www.sciencedirect.com/topics/engineering/balanced-rudder

(Author is not a fan of the semi-balanced skeg rudder.)

And of course sail plan, sail trim and shape, rig rake and hull shape have easily as much or more to do with helm balance.  I'm always amazed that a 1" -2" drop of a traveler on a well-set up 50'er can change the helm angle by a couple of degrees or the feel by a couple of pounds of pull.

I think you'd only want a completely balanced rudder for an auto-pilot. Save a lot of amps that way. However for a helmsman constant and immediate feed-back on what's happening down there is mighty handy to have, and if the rudder is completely balance that's not happening.

    

 

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On 8/1/2020 at 10:44 AM, Mark K said:

How the rudder is balanced, as in how far forward the rudder post is in the foil, has a big effect on the feel. My guess is the rudder on that boat has the post near the front of the foil. He was just bitching about the pull on the tiller but he was probably only holding about 4-5 degrees of weather helm. 

 

This, I have an old Farr 1020 and the load on the tiller can get pretty heavy as soon as you move it very much off center. Boat would track right with other boats that looked like they were pointing much higher.

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I experienced a sailing epiphany once upon a time, on a long upwind slog. I had a blade up with one reef in the main, my buddy sailed up from behind and passed me easily and started sailing away, my reefing system was clumsy and not well thought out, but I refused to lose and dropped the blade and instead of going to the #3 we changed to the #1, (Nothing in-between at that time). We instantly gained both height and speed, and the helm went from a hand brake to a nice two to three finger balance. Sailed past my friend and beat him back to the marina by hours. After I had passed him as I looked back he was trying sail evolution after evolution as he had always beaten me before in those conditions. Some boats want or require you to think outside what is considered the "proper trends" of the time. In this case a high roach main with a blade vs. a reef in said main, with a 150% deck sweeper and  tada! Beast vs. beauty. The ephiphany = the boat I had was  balanced by the foresails, I ended up with six of them over time; storm, yankee, blade, traditional #3, high clew 135 and the 150. Used every single one of them on one interisland frolic + the kite. 

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10 minutes ago, Moore Play said:

I experienced a sailing epiphany once upon a time, on a long upwind slog. I had a blade up with one reef in the main, my buddy sailed up from behind and passed me easily and started sailing away, my reefing system was clumsy and not well thought out, but I refused to lose and dropped the blade and instead of going to the #3 we changed to the #1, (Nothing in-between at that time). We instantly gained both height and speed, and the helm went from a hand brake to a nice two to three finger balance. Sailed past my friend and beat him back to the marina by hours. After I had passed him as I looked back he was trying sail evolution after evolution as he had always beaten me before in those conditions. Some boats want or require you to think outside what is considered the "proper trends" of the time. In this case a high roach main with a blade vs. a reef in said main, with a 150% deck sweeper and  tada! Beast vs. beauty. The ephiphany = the boat I had was  balanced by the foresails, I ended up with six of them over time; storm, yankee, blade, traditional #3, high clew 135 and the 150. Used every single one of them on one interisland frolic + the kite. 

If by slog you mean a seaway, then yes, invariably a boat with a genoa, or better yet a No. 2 or a heavy No. 1 with a hollow leach will beat a boat with a blade or No.3 up.  Those sails have a lower CE so you can power up more, which is what you want in a seaway.  In flat water, you will sail higher and faster with a blade.

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5 hours ago, Mark K said:

I think you'd only want a completely balanced rudder for an auto-pilot. Save a lot of amps that way. However for a helmsman constant and immediate feed-back on what's happening down there is mighty handy to have, and if the rudder is completely balance that's not happening.

    

 

+1

I had a boat with an outboard rudder and the tiller pressure was due to the unbalanced rudder.  A lot of other guys with the same boat didn't like it, but personally I loved it.  Mind you I was 30 years younger then so I may not feel the same way today.

I drove a boat with a balanced rudder and hated it - no feel at all.  Was like driving a '59 Caddy with power steering vs a Lotus Elan. 

Could not get the boat in a groove upwind at all, probably due to lack of familiarity so I would have figured it out at some point, but gawd I hated the feel, or lack thereof.

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If by slog you mean a seaway, then yes, invariably a boat with a genoa, or better yet a No. 2 or a heavy No. 1 with a hollow leach will beat a boat with a blade or No.3 up.  Those sails have a lower CE so you can power up more, which is what you want in a seaway.  In flat water, you will sail higher and faster with a blade.


That's kinda my point! Yes, it was definitly in a seaway (from Barbors Point to Waikiki, short tacking between the trash line current and the shore), wind = 15-20 with 25+ gusts. It was frustration that led me to fly the #1, but it worked!!! If I had had a better reefing system worked out at the time, I probably would have just shaken out the reef and excacerbated the heavy helm. BUT by going to the #1 with one reef I stumbled on to the sweetest trim for that boat in those conditions. The overused cliche, "think outside the box". TBH, I wasn't really, I just couldn't let my opposition sail away and not try and do anything about it. Normally I would never have hoisted the #1 over 15+TWS, but in this case it was magical and led me to a much deeper understanding of that boat. Part of the fascination I have with sailing revolves around this.
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1 hour ago, Frogman56 said:

Something else happening really. There should be no difference in the CE height between the blade and an overlapper.

Probably with a reef in, just not enough helm?

Okay, I should have said an overlapper with reefed main vs full hoist blade & main.  Twist off the sails.  Hollow leech overlapper even better.  Whatever it takes to lower the CE while keeping as much power on as possible - in a seaway.

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On 7/24/2020 at 2:48 AM, Renegade-27 said:

Hi all - cruising boat/weekend racer here - a lifelong sailor with lots of experience.  I have a 35' 'production' boat shoal draft that I'm just not happy with its sailing characteristics.  Specifically, it rounds up constantly.  Other than alway pushing on how much sail we carry, I've come to believe this is because the rudder for this shoal draft version is cut short as well as stalls out easily even at 15 kts apparent.

What does the group think about replacing this with a deeper rudder to keep steering control in an upwind blow?

Also, is there more to it than depth and width?  Would I be able to use a well chosen rudder from a different boat - say a C&C110 rudder on a Beneteau 35?

The rudder depth could go from 4'9" to 6'... would this be enough of a difference to be worthwhile?

Things that affect stalling.

  • Load = angle of attack
    • This is all about sail balance
  • Profile Area/size
    • Similar to load
    • Load/Area=Pressure is the key with these two items.
  • Aspect Ratio
    • High AR usually means it will stall earlier, probably not the case here.
    • Elliptical load distribution also leads to sudden stalls, rather than partial stalling.
  • Areation
    • Is air being sucked down the blade and causing an artificial stall.
  • Section Shape
    • Is the leading edge somewhat elliptical or round or bluff?
    • Is the section anything other than a NACA 00xx series?
    • Is the blade thickness outside the range 8-14% of chord length?
  • Surface finish/roughness
    • What's the surface finish like? Leading edge rough as guts, any decent chips? Lots of growth, barnacles in particular?

We need to see a photo of the rudder as it is sailed, not after a jet blast or painting. Some foils have real trouble with even a small amount of roughness, particularly on the leading edge. It might just need some TLC.

 

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On 8/2/2020 at 5:54 PM, 12 metre said:

+1

I drove a boat with a balanced rudder and hated it - no feel at all.  Was like driving a '59 Caddy with power steering vs a Lotus Elan. 

Could not get the boat in a groove upwind at all, probably due to lack of familiarity so I would have figured it out at some point, but gawd I hated the feel, or lack thereof.

That is a tough position to be in.
When you find the groove, which is really more of an overall feel of the boat from every extension of your body and mind, It is truly amazing and a real game changer in your overall outlook on sailing. I have experienced this feel in both Traditional Sailing and Land Sailing. When the foils line up properly, you will know. At that point, you just hold the tiller in your hand, not grab it, but hold it like.........................................................................I'll let your mind wander, because I cannot find the proper words. It's almost better than sex.

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When the foils line up properly, you will know. At that point, you just hold the tiller in your hand, not grab it, but hold it like.........................................................................I'll let your mind wander, because I cannot find the proper words. It's almost better than sex.

Once again the two are related; like..... "a good woman holds her man". Sir Jackie Stewart F1 champion, on how to properly grip the steering wheel.:D

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People who use the pressure on the tiller to guide them to windward, may not understand sailing.

My last boat planed with the kite up.  On transition from displacement the tiller feel changed, went completely neutral.  Light as and the course was set either by the race course itself or the fastest angle.  When going to windward in displacement mode, the best angle was governed by the rig, the apparent wind, not the load on the foils.

From the helm on a beat, I could see the front row of tell tales on the heady, they were my guide, combined with heel angle.  WTF are people talking about here with weather helm being theirs?

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12 minutes ago, astro said:

People who use the pressure on the tiller to guide them to windward, may not understand sailing.

My last boat planed with the kite up.  On transition from displacement the tiller went completely neutral.  Light as and the course was set either by the race course itself or the fastest angle.  When going to windward in displacement mode, the best angle was governed by the rig, the apparent wind, not the load on the foils.

From the helm on a beat, I could see the front row of tell tales on the heady, they were my guide.  WTF are people talking about here with weather helm being theirs?

Looks like this Randumb sock has cast his trolling line into this thread.

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On 7/24/2020 at 3:42 PM, Renegade-27 said:

Thanks again everyone.  Learned quite a bit.  Even got to tolerate insults by someone hiding behind big technical words and without actually offering any suggestions.   This MIT PhD in Mechanical Engineering : Fluid Mechanics and Heat Transfer (really) with 55 years of competitive sailing has learned that usually its the smallest people who like to throw around the biggest words. 

Some comments, like feather to weather, are great, but miss the point that the rudder is going useless.  When I can sit on the edge and feather its great - a gust can cause me to lose that edge.

I really appreciate the perspective about overall balance and what is needed is to stop the weather helm.  Heel and sailplan.  Balance the boat.

I'm usually singlehanded so weight on the rail isn't much of an option, but I'm going to dramatically reduce main (reef at 10-12; 2 x reef at 13-14 true).  I can't shorten my forestay easily (fixed length) but the next step would be to have the yard shorten it.  Lastly if that still proves a problem, the 'Fence" seem interesting.  I bet I am lifting rudder out of the water and ventilating.  Just read a technical paper on ventilation in foils and I think that could well be what's happening when all else is unbalanced forcing a 20+ degree helm.

I have an old Beneteau 325 with a very tall mast  (and narrow stern) due to the normally light winds in my area.  I completely understand your situation.  In 6-12 kts of wind the boat is a dream.  In 15+ kts it is "lively" and above 18 kts it is just not fun.  The previous owner would just call off racing if wind was supposed to be over 15kts.

I did much of what has been suggested: shorten the forestay, use the babystay, hydraulic backstay replased the old screw to flatten main more quickly.  Harken traveller replaced old Amiot with good purchase and gross(6:1)/fine(18:1) tune on the mainsheet.  Reef very early and sail the boat flat as possible.  Feathering really helps but some good hands on the main and vang are the best countermeasures.  I have a tiller and can really feel any loading on the rudder.

A marine architect suggested moving the keel when I was thinking about adding a bulb.  In the end, I would sell the boat before doing either.

When I have other very experienced helmsmen on long distance races, they never expect or anticipate the loss of control in sudden heel situations.  Anticipation/early action and quick jerks to throw off the ventillation are the only things that you can do from the helm.

Longer rudder than the keel? (I wouldn't)  Changing the shape of the rudder to a more stall tolerant shape? (I have not but I think that is a next approach after everything above)

 

Good luck!

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Thanks, Cmass.  This weekend I was booking along with maybe 7 or 8 knots when a big black cloud appeared above us on the lake and I saw a big gust on the water ahead.  I bore off to about 60-70 degrees, let off the main (dramatically) and loosened the jib.  Wind hit at about 17-18, immediate roll to leeward (heel) followed by responding like a cork under water with the boat flying into and then through the wind.  No chance in control at all.  My wife screaming from down below how she'll never go sailing again (again :D).

I'm likely going to move on to my next boat.  Got several in mind - - but that's a different thread.

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4 hours ago, Moore Play said:

When the foils line up properly, you will know. At that point, you just hold the tiller in your hand, not grab it, but hold it like.........................................................................I'll let your mind wander, because I cannot find the proper words. It's almost better than sex.

Once again the two are related; like..... "a good woman holds her man". Sir Jackie Stewart F1 champion, on how to properly grip the steering wheel.:D

Well said. Moore

 

 

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On 7/23/2020 at 12:48 PM, Renegade-27 said:

Hi all - cruising boat/weekend racer here - a lifelong sailor with lots of experience.  I have a 35' 'production' boat shoal draft that I'm just not happy with its sailing characteristics.  Specifically, it rounds up constantly.  Other than alway pushing on how much sail we carry, I've come to believe this is because the rudder for this shoal draft version is cut short as well as stalls out easily even at 15 kts apparent.

What does the group think about replacing this with a deeper rudder to keep steering control in an upwind blow?

Also, is there more to it than depth and width?  Would I be able to use a well chosen rudder from a different boat - say a C&C110 rudder on a Beneteau 35?

The rudder depth could go from 4'9" to 6'... would this be enough of a difference to be worthwhile?

Does it round up in gusts, or just excessive weather helm?

Edit: Never mind.

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On 8/2/2020 at 8:29 AM, Left Shift said:

Farr has designed some of the best and most "driveable" rudders on production boats, e.g. the Farr 39 and Farr 40 design types of the mid-'90s to mid '00s.  Fairly deep, moderately short chord length, forgiving NACA section and about a 7:1 balance between the front and back of the shaft centerline.  They do have a fairly solid feel of two or so pounds of "tug" when you are set up for good upwind performance, I've found.  And they grip exceptionally well under reaching loads and give you a decent bit of notice before they stall out.  

Nothing wrong or very extreme about this rudder.  Looks decently balanced as well.

Screen Shot 2020-08-01 at 3.25.06 PM.png

Not if you include the old beach balls. They spun out with shit rudders downhill. When they replaced them with the farr 40 rudders, they became sailable.

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On 8/5/2020 at 8:12 AM, Renegade-27 said:

Thanks, Cmass.  This weekend I was booking along with maybe 7 or 8 knots when a big black cloud appeared above us on the lake and I saw a big gust on the water ahead.  I bore off to about 60-70 degrees, let off the main (dramatically) and loosened the jib.  Wind hit at about 17-18, immediate roll to leeward (heel) followed by responding like a cork under water with the boat flying into and then through the wind.  No chance in control at all.  My wife screaming from down below how she'll never go sailing again (again :D).

I'm likely going to move on to my next boat.  Got several in mind - - but that's a different thread.

Get  a cat if you insist on taking a wife.

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On 8/5/2020 at 4:30 AM, 12 metre said:

Looks like this Randumb sock has cast his trolling line into this thread.

Oh really?

Looks like I am right tho hey?

847eed2503bf544f997b97a76a573cde.gif

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On 8/5/2020 at 8:12 AM, Renegade-27 said:

Thanks, Cmass.  This weekend I was booking along with maybe 7 or 8 knots when a big black cloud appeared above us on the lake and I saw a big gust on the water ahead.  I bore off to about 60-70 degrees, let off the main (dramatically) and loosened the jib.  Wind hit at about 17-18, immediate roll to leeward (heel) followed by responding like a cork under water with the boat flying into and then through the wind.  No chance in control at all.  My wife screaming from down below how she'll never go sailing again (again :D).

I'm likely going to move on to my next boat.  Got several in mind - - but that's a different thread.

Hiya Renegade,

Yep, flick it and go shopping. I've got a fairly wide arse and it just loves 15-20 degrees heel to windward (dual rudders). The boat feels planted and only needs a couple of degrees more on the helm in the gusts to keep the forestay at the same angle to the horizon.

I can overpower the rudders pretty easily with the wrong sail trim (think falling off from a reach without easing traveller or main), but even all fucked up and with too much heel the boat will be slow to round up. In big gusts under too big a kite she will heel quickly, but still turn up slowly. 

Edit: whatever you do, do NOT give it a fistful of helm when you heel over.  Giving it a lot of weather helm drives your stern upwards and to windward and pushes the bow down and to leeward, which......makes you round up.

A little helm, never lots. 

Cheers,

SB

        

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On 8/5/2020 at 4:17 AM, astro said:

People who use the pressure on the tiller to guide them to windward, may not understand sailing.

My last boat planed with the kite up.  On transition from displacement the tiller feel changed, went completely neutral.  Light as and the course was set either by the race course itself or the fastest angle.  When going to windward in displacement mode, the best angle was governed by the rig, the apparent wind, not the load on the foils.

From the helm on a beat, I could see the front row of tell tales on the heady, they were my guide, combined with heel angle.  WTF are people talking about here with weather helm being theirs?

giphy.gif

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On 8/4/2020 at 11:57 AM, Cmass said:

Reef very early and sail the boat flat as possible.  Feathering really helps but some good hands on the main and vang are the best countermeasures.  I have a tiller and can really feel any loading on the rudder.

A marine architect suggested moving the keel when I was thinking about adding a bulb.  In the end, I would sell the boat before doing either.

When I have other very experienced helmsmen on long distance races, they never expect or anticipate the loss of control in sudden heel situations.  Anticipation/early action and quick jerks to throw off the ventillation are the only things that you can do from the helm.

Too right old chap

14 hours ago, astro said:

Oh really?

Looks like I am right tho hey?

Having grazed upon astro's 'posts' in the pasture of a fine thread, the man of even average intelligence will bend his legs ever so slightly, to plop a plum patty 'pon the ground: a seed within will sprout a stem, which will in turn unfold a leaf, and as varried as may be the cheeks from which it issued forth, it's veiny striations will scribe the same message, the response of every man and beast immemorial and forevermore to have sampled such delights:

 

lol.

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Hahahahahaaa

So it's a choice we all have.  As you are carefully watching the sails as you steer to windward, the amount of work you have to do on the tiller or wheel is your choice.  You can steer the same angle and have the rudder nearly rip you arm out of its' socket, or you can rest easy and with no more that a couple of finger tips guide it along.

Go ahead, select your own battle, select your own speed.

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23 minutes ago, astro said:

Hahahahahaaa

So it's a choice we all have.  As you are carefully watching the sails as you steer to windward, the amount of work you have to do on the tiller or wheel is your choice.  You can steer the same angle and have the rudder nearly rip you arm out of its' socket, or you can rest easy and with no more that a couple of finger tips guide it along.

Go ahead, select your own battle, select your own speed.

So they're the only options; feather light touch or shoulder dislocation, really? You're being stupid.

Everyone else acknowledges that each boat has a sweet spot of load on the rudder and that it is never to the lee (ie adding more side force onto the keel)...that's all. If the tiller/wheel load is too much either the rudder is loaded too much or the designed mechanical advantage is wrong.

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1 hour ago, Ncik said:

So they're the only options; feather light touch or shoulder dislocation, really? You're being stupid.

Dr Astro prescribes that you take a dose of keep doing what you are doing, even if it means dragging a slot through the water with a rudder sideways ... because ... well because!

giphy.gif

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Is there some Aussie bitch fight  going on here? 

Boats are boats. If a driver cannot feel the boat, give them the boot

If the boat has a design flaw, that is a whole difference.

We have all experienced syenergy, it is special and should be remebered.

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1 hour ago, astro said:

Dr Astro prescribes that you take a dose of keep doing what you are doing, even if it means dragging a slot through the water with a rudder sideways ... because ... well because!

giphy.gif

You're a fool for wasting my time.

I'm a fool for being drawn into your stupidity.

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In the class I sail most, a 20ft open keelboat,  we set the boats up, by tilting the mast back,  so there is significant round up.  Without it you'll find yourself at the back of the fleet at the end of the first windward leg.  We've had  sailors come in, buying class winning boats and are not used to the feel, they immediately push the mast more vertical to make the helm more neutral and go nowhere fast.  ( note we're an almost one design class the biggest difference in boat speed is caused by the nut on the helm) 

The class has two rudders available,  the original,  was skeg hung,  trapezoid shape,  the new rudder very like the one on the keelboat  shown previously.  The boats still have to be set up to round up, to win. 

The difference between the two,  in handling,

You experience uncontrolled round up earlier with the old rudder,  but it is a more gentle transition than the new rudder which let's go suddenly. 

If you have to crash tack instead of sailing the tack,  boats with the new rudder recover boat speed more quickly .

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1 hour ago, The Q said:

We've had  sailors come in, buying class winning boats and are not used to the feel, they immediately push the mast more vertical to make the helm more neutral and go nowhere fast. 

So you are telling us that new people come into the class, go nowhere fast and come at the back of the fleet?

How could that possibly happen?

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9 hours ago, astro said:

So you are telling us that new people come into the class, go nowhere fast and come at the back of the fleet?

How could that possibly happen?

New people who have had success in other classes. 

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3 hours ago, The Q said:

New people who have had success in other classes. 

Yeah, that's what I assumed, but who would have thought hey, new to the class and they don't win!

Must be because they don't have enough weather helm.

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On 8/4/2020 at 6:12 PM, Renegade-27 said:

Thanks, Cmass.  This weekend I was booking along with maybe 7 or 8 knots when a big black cloud appeared above us on the lake and I saw a big gust on the water ahead.  I bore off to about 60-70 degrees, let off the main (dramatically) and loosened the jib.  Wind hit at about 17-18, immediate roll to leeward (heel) followed by responding like a cork under water with the boat flying into and then through the wind.  No chance in control at all.  My wife screaming from down below how she'll never go sailing again (again :D).

I'm likely going to move on to my next boat.  Got several in mind - - but that's a different thread.

Funny,

My wife cannot be bothered with light air sailing...only likes it when we are "screaming along" at 7-8 kts.  If you are going to run before the storm, you have to get to 130-150 apparent.  If you try to hang out at 90 when the big puff hits, the boat will turn you.  Easing sails and turning down a little makes the boat more powerful but also gives you time to react before the auto-tack.

I always approach the gusts by going closer to the wind.  Give the sails just enough power to keep you going at hull speed but not enough to over-heel your boat.  Main and helm work together to balance the heel, nothing else matters.  In those situations, vang is manned or off.  Traveller is not fast enough response so the gross on the main and the helm are the too biggest fast reaction tools.  Twist in the headsail but don't ease, it is fighting your rounding up.  

I race a lot on Jboats, 24, 35, 105 and 120 and have done many thousands of miles of deliveries in the 105 and 120.  Hard to match the ease of sailing on those boats and their balanced helms.  

Have fun and good luck!

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  • 2 months later...
On 7/28/2020 at 9:49 AM, KC375 said:

I'm no expert surfer (actually I'm very bad) but on both my windsurfer and my not very impressive surfing efforts the turn to starboard while heeled to starboard is a function of the rotation applied to the board by my feet. 

Wrong. Try riding one out on your stomach and steer with body lean. Works the opposite of a displacement hull under heel. Rotation generated with your core transmitted through your feet is much weaker and best used when the board is unloaded, as when banging the top of the wave for a drop in or cutback.

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5 minutes ago, kinardly said:

Wrong. Try riding one out on your stomach and steer with body lean. Works the opposite of a displacement hull under heel. Rotation generated with your core transmitted through your feet is much weaker and best used when the board is unloaded, as when banging the top of the wave for a drop in or cutback.

That may explain my limited success with a surf board

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33 minutes ago, KC375 said:

That may explain my limited success with a surf board

I talk surfing much better than I do surfing.

New thought: looking at OP's boat specs the first thing that jumped out at me was the low ballast to displacement ratio. Could it be the boat is simply too tender? My boat's ratio is in about the same range and I compensate with all the depowering tricks suggested upthread but I always said Bruce Farr wanted speed and was prepared to trade ballast for crew weight on the weather rail. Since I, like everyone else these days, am usually short handed, this is more of an issue than for something like a Sparkman Stephens design from thirty years ago.

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