Question Question about weather helm and rudder shape, Aerosouth rudder etc.

Whatever.
Cascadian wanted to find out what the rudder actually felt like from someone who had sailed one. I have.
I threw in the keelboard for good measure.
 
You're welcome.
I have a technical background, I've been sailing a long time, 23 in a Sunfish, and this is the next step in it's evolution.
I didn't think it would be so radically different until I read an article about the design process by the designer, and decided to try it. He said modeling only went so far, and he went through 150 iterations before he found what worked best. I've read what people have written about this stuff and why it won't work, but the only bad I read about them (from a user) is that he broke his on a rocky bottom.
Look around, people are already copying this design, because it works. Soon, you'll see these design features appearing on new boats, because they work.
Nay sayers, read the attached article. This guy is the Bert Rutan of sailboats!
 
Oldfish newfish said:
The boat heels less (wants to sail flatter), but it's faster, no doubt.
My wife noticed the difference in heel from shore.
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I think I agree with Pippins. The rudder and daggerboard shouldn’t have effect on heeling. My question is - if you can point higher as a result of these blades, would the heeling forces be less perpendicular to the boat and more from forward, reducing the heeling of the boat and lessening the need to hike?

The only way to tell the actual impact of the AS board and rudder is to do a trial with a normally set up sunfish sailed by someone equally as skilled as you and see what happens.

The AS daggerboard is pretty extreme, and the designer admits it was developed based on theory and not in-water testing, so I don’t know if it is likely better, worse or the same in performance as a Sunfish racing board.

I see that newer performance one-designs vary in their daggerboard designs. RS Aeros have a big, angled taper on the leading edge, Melges 14 boards are rectangular, and I cannot tell for sure about the D-Zero, so there is no consensus on daggerboard shape.
 
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I made my own. Easy. Helm is neutral and the y grandkids can easily handle it. Note also Dynema bridle and Rear port. I glassed in a heavy transom mount for the rudder bracket. White oak. The coloration is from the retrofit from the old style rudder bracket.
 

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Very similar to what andyatos did earlier:

Picture Of My New Vertical Rudder

Took my old mahogany daggerboard that I was no longer using and re-purposed it as a vertical rudder. Photo below. Features include... - The trailing edge of the old daggerboard is now the leading edge of the new rudder. - Fully glassed the rudder head. So no chance of cracks in the wood...
sailingforums.com sailingforums.com

Old timers will remember that (about ten years ago) the class (ISCA) had a long fight about changing the rudder angle. Ultimately, the proposal was not accepted although just about all the racers felt it would be an improvement. The reason for the rejection (as I recall) was that it would be too expensive/cumbersome for those sailing in other countries. Not a very strong argument, IMHO.
 
Wavedancer said:
Very similar to what andyatos did earlier:

Picture Of My New Vertical Rudder

Took my old mahogany daggerboard that I was no longer using and re-purposed it as a vertical rudder. Photo below. Features include... - The trailing edge of the old daggerboard is now the leading edge of the new rudder. - Fully glassed the rudder head. So no chance of cracks in the wood...
sailingforums.com sailingforums.com

Old timers will remember that (about ten years ago) the class (ISCA) had a long fight about changing the rudder angle. Ultimately, the proposal was not accepted although just about all the racers felt it would be an improvement. The reason for the rejection (as I recall) was that it would be too expensive/cumbersome for those sailing in other countries. Not a very strong argument, IMHO.
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As I recall none of the countries aside from the US voted for the new rudder. So the vote was like 10-1 against the change.
 
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I don't think the blades on the sunfish have ever been the limiting factor on pointing. The shape of the sail is what drives the Sunfish to tack at the angles it does. Anyone that has raced in a mix fleet of Sunfish and Super Sunfish notice this quickly with the Supers pointing much higher.

I would expect a Sunfish with faster blades (and the resultant faster hull speed) to actually point lower, with the same apparent wind, but a better VMG.
 
Cascadian505 said:
Yeah the Aerosouth looks a little skinny an an area that has a lot of torsion.
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I bought one of the first AeroSouth rudders and it did break after just a few outings. I contacted them and they noted that they had improved the design to address that, and sent me a new one free of charge. I have had it now for 3 years and I love it. It reduces the weather helm tremendously. My only complaint is that it is so long that it kicks up while I am still a several yards from shore and I lose steering before I want to.
 
Fremont said:
I have a knockoff of the aero south rudder that I bought on eBay. Makes for a lighter helm, and has better bite when the boat heels over on big gusts. It has accidentally kicked up on me a time or two, not sure if it hit a seaweed tangle.
Also I get a hum at speed. The daggerboard already does that, I think this rudder does it too.
I'm probably going to go back to the standard rudder just to compare the feel.
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I have both the official AeroSouth rudder that I use on my Sunfish and Super Sunfish, and more recently I bought the shorter knockoff for my wife's Minifish and I noticed the same problem that you described where the knockoff seems to pop up too easily. I think the hole where the pin goes that holds the spring should be further back to create more tension on the spring.
 
andyatos said:
From looking at the pictures of your sail, cunningham and outhaul I think there's two possibilities. First, from what I can see, you've got a 2 to 1 mechanical advantage on your cunningham. Can't quite tell with your outhaul but looks like 2 to 1 also? As I remember, I've got 3 to 1 on my cunningham and at least 4 to one on my outhaul.

So, I'm able to pull quite a lot of tension through my luff and the lower 3rd of the sail. ....
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Andy, when you get a chance, I'd like to see your setup for your outhaul and cuningham lines. Curious as to how you get the 3:1 and 4:1 advantage without the lines getting all bunched up in the end cap.
 
Pippins said:
<snip>
The Aerosouth rudder doesn't affect weather helm so much as it effects effort to counteract the weather helm. The center of effort of the rudder on a sunfish rudder is ten or twelve inches behind the axis of the rudder pin. The Aerosouth rudder moves this center of effort to more inline with the rudder axis. If you want a rudder with even less effort you'd add area to the rudder ahead of the rudder axis to create a more "balanced" rudder.
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I don't think I have fully understood this point until now, when you explained it so clearly. Thank you! AreoSouth claims that their rudder also has less drag, which I feel is true, though it is difficult to compare even on the same day when swapping out rudders considering there are so many other variables that affect speed.
 
Weston said:
Andy, when you get a chance, I'd like to see your setup for your outhaul and cuningham lines. Curious as to how you get the 3:1 and 4:1 advantage without the lines getting all bunched up in the end cap.
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I will do that. I may be able to take pictures/shoot video tomorrow. Stand by!

- Andy
 
@Weston here is a common set up for a 6 to 1 on both the Cunningham and outhaul (3 to 1 on the boom with an additional 2 to 1 at the sail).

On the Cunnigham the grommets on the sail act as turning blocks with the line going through the tack, up to the Cunningham grommet and finally terminating back at the tack. On the 3 to 1 on the boom, a stainless thimble is a cheap way to reduce friction.

For the outhaul the same set up as the Cunningham can be used. I like to leave a long tail on the outhaul and lead it forward over the gooseneck, around the mast and tied back to something on centerline (I use the strap in front of the centerboard on my boat). I put a ball stop on mine near the clam jam cleat at a location that would correspond to the maximum ease I would ever use. I tie a hand loop in the line somewhere near the daggerboard. This setup is so effective am pretty sure I could tear the clew off the sail if I wanted. I also run the line inside my sail ties so it doesn't fowl anything (this won't work with shower clips). I like to clock my clam jam slightly to starboard side of the boom so it is more accessible on starboard tack but not inaccessible on port (this also gets it clear of the mainsheet block for my particular favorite location). Since the sunfish boom is very flexible I lead the outhaul line from the clam jam cleat, under boom and through the end cap on the port side (this forces the line to take a bend with the boom lessening any change in outhaul tension with the boom flexing).

1/8 inch dyneema work very well for the lines. Keys to making this work well is thinking about the required adjustment range and tying your lines and appropriately so you don't have too much line hanging around to catch you while sailing. Note that all this is done with only two lines and no cuts, so you can tie and retie until you are happy with it. Also, when you rig, double check your lines, one time I started a regatta with my sheet and mainsheet block trapped inside the outhaul purchase lines, that didn't work well at all.
 

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Weston said:
Andy, when you get a chance, I'd like to see your setup for your outhaul and cuningham lines. Curious as to how you get the 3:1 and 4:1 advantage without the lines getting all bunched up in the end cap.
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Hi Weston, Pippins just answered your 3:1 and 4:1 questions for me with his recent post with pictures. My set up is similar to what he describes with "3 to 1 on the boom with an additional 2 to 1 at the sail". The difference is mine is more complex because I wanted to see what the friction would be like with pulleys/blocks almost everywhere.

If you still would like to see pictures of my set up, I'll take some and post them for you. But if you are looking for a simple and less expensive arrangement that does what mine does, just copy Pippins' set up.

Cheers,

- Andy
 
Before you do anything else make sure you are not seeing load on the tiller as weather helm.

On my Laser I make a mark in the middle of the back of the cockpit so I can check that the tiller is centralised. If your boat is going straight with the tiller in the middle and the with a heavy load on the tiller that's manageable. If you want to reduce the load on the rudder then you have to move that load to the dagger board by moving the rig forwards.
 
Riv said:
Before you do anything else make sure you are not seeing load on the tiller as weather helm.

On my Laser I make a mark in the middle of the back of the cockpit so I can check that the tiller is centralised. If your boat is going straight with the tiller in the middle and the with a heavy load on the tiller that's manageable. If you want to reduce the load on the rudder then you have to move that load to the dagger board by moving the rig forwards.
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@Riv , load on the tiller is weather helm by definition. When you let go of the tiller of the boat rounds up to the wind you have weather helm, if it drives down you have lee helm. The direction of load on the tiller is letting you know what face of the rudder is working, and the amount of force you feel is an indirect measurement of the angle of attack AoA of the rudder.

Displacement of the tiller from centerline of the vessel is NOT directly related. The AoA of the boat hull with respect to the water is almost never 0 degrees which is why rudder displacement from centerline is not indicative of the AoA of the rudder through the water. Factors that effect the AoA include the heel of the boat (and resultant non symmetric waterplane), gybing centerboards, FTE boards, point of sail, and the relative speed of the boat, among others.

Most high performance fixed foil planning boats have an AoA of maybe 1 degree on the main foil (with more AoA at slower speeds and less at higher speeds). The rudder tends to operate at a slightly higher AoA like maybe 1.5 degrees, as such you can expect 2 or 3 degrees deflection of the rudder head from the hull.

A sunfish with a 43 inch tiller will have 1.5 inch of deflection on 2 degree AoA (43*sin2°). To make this displacement even more confusing the play in the pintles, rudder head and flexing of the tiller (my ash tiller will take a visual bend) will further bring the tiller off centerline.
 
Pippins said:
The rudder tends to operate at a slightly higher AoA like maybe 1.5 degrees, as such you can expect 2 or 3 degrees deflection of the rudder head from the hull.
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Where's the edit button, brain fart here, this isn't cumulative. I'll still stick by 2 degrees AoA as a reasonable number for a sunfish rudder.

In general I do not chase weather helm adjustments with the sunfish. Efforts to reduce weather helm by moving the goose neck aft on the boom have never resulted in more speed for me personally. I almost always sail with the goose neck really forward like 10 to 12 inches and rarely ever father aft then 14 inches.

The distance from the center of effort of the sail to the mast head and the distance from the mast head to the goose neck make it so the effect of moving the goose neck one inch results in moving the center of effort of the sail a fraction of an inch.

I could see some benifit in added vang action with a more rear biased goose neck position (and by vang action I mean bending the boom down to draw draft out of the sail).
 
“I almost always sail with the goose neck really forward like 10 to 12 inches and rarely ever father aft then 14 inches.”

I don’t mean to be snarky, but if you attend a Sunfish regatta with good sailors, it’s blowing maybe 17-20, and you have your gooseneck like that, you will find that the good sailors leave you in the dust upwind. Their goosenecks will be back around 17-19.
 
beldar boathead said:
“I almost always sail with the goose neck really forward like 10 to 12 inches and rarely ever father aft then 14 inches.”

I don’t mean to be snarky, but if you attend a Sunfish regatta with good sailors, it’s blowing maybe 17-20, and you have your gooseneck like that, you will find that the good sailors leave you in the dust upwind. Their goosenecks will be back around 17-19.
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I do, and they don't.
 
beldar boathead said:
Please show some results. If you are correct, you should go to the North Americans and you will win.
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@beldar boathead, your initial response was snarky, your follow-up response was condescending. I will cede that my response to your comment was not constructive. At no point did I suggest my set up would work for everyone, just an interesting observation I have noticed from my own racing (successfully at times) over the past 35 plus years. I come here to share my thoughts, experience and joy in sailing, and not to stroke my ego. Feel free to review my posts on this forum and show me a post where I was blatantly disrespectful to someone else.
 
Pippins said:
@beldar boathead, your initial response was snarky, your follow-up response was condescending. I will cede that my response to your comment was not constructive. At no point did I suggest my set up would work for everyone, just an interesting observation I have noticed from my own racing (successfully at times) over the past 35 plus years. I come here to share my thoughts, experience and joy in sailing, and not to stroke my ego. Feel free to review my posts on this forum and show me a post where I was blatantly disrespectful to someone else.
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Actually, I thought your reply to my comments was disrespectful, but I didn't have a hissy fit, I just withdrew.
 
Fremont said:
I have a knockoff of the aero south rudder that I bought on eBay. Makes for a lighter helm, and has better bite when the boat heels over on big gusts. It has accidentally kicked up on me a time or two, not sure if it hit a seaweed tangle.
Also I get a hum at speed. The daggerboard already does that, I think this rudder does it too.
I'm probably going to go back to the standard rudder just to compare the feel.
Click to expand...
I have both the AeroSouth rudder, and an imitation one off of eBay. I’ve had the same problem with the imitation one kicking up too easily. I don’t think they got the geometry right for the positioning of the pre-drilled holes for the spring peg. I’ve never had a problem with the AeroSouth rudder kicking up and I absolutely love how light it feels on the tiller. Molly, complaint with it versus the factory router is its depth. It makes it harder to keep the rudder in the water while you’re coming into shore.
 
andyatos said:
Hi Weston, Pippins just answered your 3:1 and 4:1 questions for me with his recent post with pictures. My set up is similar to what he describes with "3 to 1 on the boom with an additional 2 to 1 at the sail". The difference is mine is more complex because I wanted to see what the friction would be like with pulleys/blocks almost everywhere.

If you still would like to see pictures of my set up, I'll take some and post them for you. But if you are looking for a simple and less expensive arrangement that does what mine does, just copy Pippins' set up.

Cheers,

- Andy
Click to expand...
Actually, I was able to see your Cunningham and outhaul configuration using micro blocks on your recent Russian river video.. That was very helpful. Thank you.
 
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