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Changing Rudder Pivot Point

Hello All, I'm still new in the class and read the Dec. 8 newsletter. It appears to me that the new "ruling" is that we can change the rudder pivot point to bring the leading edge closer to the hull - and therefore better pointing? And smoother flow across the rudder causing more lift? Has anyone done this yet - drilled a new hole and moved the pivot point of your rudder? Anyone got photos of what this looks like?
 

mixmkr

Well-Known Member
I've not done this on a Sunfish, but other daysailors...infact I just made a inboard rudder on a 16 ft daysailor I have, more vertical. Not being a nautical engineer, I always thought the Sunfish rudder was too swept back and have read here and other places, being more vertical helps and makes more sense. Not worrying about class rules, I don't really contemplate such stuff (except my previous alteration I just mentioned...ha!)...but if legal, I think the point of making the rudder more vertical is OK, if wiihin certain class measurement, I'd do it. No pics, but I think figuring out the geometry of it wouldn't be a deal stopper. If you're using the tiller straps, remember to consider those.....and the springs, etc.
 

andyatos

Well-Known Member
Here's what my new Sunfish rudder looks like. It's the bottom of an old daggerboard. Just shaped the top to match my old swept back original rudder head, clamped it in place with a new set of rudder cheeks when the leading edge was vertical and drilled a hole. It feels great. No weather helm.

The lower image shows more of the boat to give you the scale of how long the rudder is. And the tiller? It's an old hockey stick.

- Andy

vertical-rudder.jpg

rudder-and-tiller.jpg
 
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L&VW

Well-Known Member
That is really cool!
Yes, reminds me of the rudders on my long-gone catamarans. :(
Here's what my new Sunfish rudder looks like. It's the bottom of an old daggerboard. Just shaped the top to match my old swept back original rudder head, clamped it in place with a new set of rudder cheeks when the leading edge was vertical and drilled a hole. It feels great. No weather helm. The lower image shows more of the boat to give you the scale of how long the rudder is. And the tiller? It's an old hockey stick. - Andy
I'm not a nautical engineer, either, but isn't all that wood affecting drag? And giving up some space when retracted for beaching or trailering? If you cut 18" off the bottom, wouldn't you have the same beneficial effect on weather helm? (And less drag?)

Isn't some weather helm desirable? :confused:

The hockey stick is a super "repurposing". Shouldn't it be wrapped with electrical tape? ;) Last time I used one, it was made of hickory—but especially if made of fiberglass, a great idea. :cool:
 

norcalsail

Active Member
Well Andy, after I get my outhaul and cunningham rigged up, maybe I can copy this modification too. I plan on taking the sail to Sausalito for the grommet this week.
 

beldar boathead

Well-Known Member
What is the grommet work needed for? The Cunningham is rigged using the first grommet up from the tack, and the outhaul of course uses existing grommets.
 

andyatos

Well-Known Member
isn't all that wood affecting drag?
Clearly, I've got a lot more surface area (drag) in the water than the stock Sunfish rudder. So, if I was sailing side by side to an identical Sunfish, with both boats flat and both rudders on the centerline at zero angle of attack, the other sailor may be faster.

However, if the other Sunfish starts to have to correct for weather helm by turning their rudder in stronger wind and I'm not, then the tables are turned in the rudder drag department.

And giving up some space when retracted for beaching or trailering?
Yes, the rudder doesn't stick way up when retracted. But it raises more than you would think. As I remember, only a tiny bit of the rudder is touching the water when raised. However, if this was a problem, you just take 30 seconds, remove the rudder and put it in the cockpit.

If you cut 18" off the bottom, wouldn't you have the same beneficial effect on weather helm? (And less drag?)
When deciding on a rudder length for this new vertical one, I used my Laser rudder as a benchmark. After I made my Laser rudder vertical, the tip of the rudder was 21 inches from the bottom of the transom. Using that as a guide, I made the tip of the vertical rudder on the Sunfish also 21 inches from the bottom of the transom.

However, when the Laser rudder was in its original, slightly swept back position, the bottom of the rudder was 18.5 inches from the bottom of the transom. So I may cut a bit more off the bottom of my new vertical rudder for the Sunfish.

Isn't some weather helm desirable?
Yes, it is.

Good questions all though L and V! :)

- Andy
 
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andyatos

Well-Known Member
What is the grommet work needed for? The Cunningham is rigged using the first grommet up from the tack, and the outhaul of course uses existing grommets.
If I may reply for NorCalSail, we are trying to match the grommet size and reinforcement panels (more than 3 layers of cloth) that are on my Intensity Sunfish sail. See the image below. NorCal's Sunfish sail doesn't have this reinforcement. I don't think the grommet size matters much but I believe having reinforcement panels does.

After all, I'd hate to have NorCal pull on his cunningham and tear out the grommet. Which is what happened to me when I showed my buddies my brand new cunningham while the boat was fully rigged on the trailer at the boat ramp. Tore the grommet and the luff right out on what I thought was a tough race sail that came with the boat! :eek:

- Andy

Sunfish Intensity Sail Cunningham No Arrows.jpg
 
Not sure that the rudder is legal for official regatta use. Clearly the shape of the rudder is non-standard. Also if you have ever seen a class measurer evaluate a boat they measure the angle between the boat and the rudder. It looks like this rudder would not comply with class rules.
 

beldar boathead

Well-Known Member
I see about reinforcing the grommet. I have been sailing Sunfish since my cone was much smaller. Back then, we used the Cunningham adjustment without any reinforced grommet and it was fine. But when the racing sail came out they provided the reinforcement, and obviously reinforcing it is a wise idea! I did not know the recreational sails don't come reinforced. BB
 

andyatos

Well-Known Member
I did not know the recreational sails don't come reinforced. BB
To be honest BB, at the moment I'm drawing a complete blank as to what NorCal's area of his recreational sail luff at the first grommet up from the tack looks like. So, I'm assuming that I looked at it and said to myself, "Ok, this area needs to be reinforced before we fashion a cunningham."

And as far as the size of your cone is concerned, at least you have a cone with the accompanying additional grey matter. Cause I could use some more grey matter right now to extract the phantom image somewhere in my brain of NorCal's first grommet area!! :rolleyes:

Ga Day, Mate...

- Andy
 

sailcraftri

Well-Known Member
I'm slightly confused going back to the original question of the new rule for rudders. Here is the voted rule 3.3.3

... New Rule 3.3.3
The Sunfish rudder may be modified by drilling a new pivot point hole and attaching the tiller bolt where the original pivot point was so the angle between the leading edge of the rudder and the centerline bottom of the hull is no less than the approved angle. The modified rudder shall match the template. A skipper may choose to sail with a standard or a modified rudder as long as they do not change it during a regatta.

So I look at this that the rudder still must be minimum 120 degrees from the hull centerline (based on the figure in the class rules). But if you use the original pivot point now for your tiller are you not raising the rudder up higher?

Does someone have a photo of this modification?

Is this rule for those rudders that were more than 120 degrees and therefore a way to correct that?
 

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beldar boathead

Well-Known Member
The communication about this has been sparse. I race a fair amount and had never heard of the idea being proposed. I think it is to make the blade almost vertical if you want - similar to a Laser. I know World Sailing will need to approve the change but I don't know when they would be reviewing the change. It will take some skill to drill the hole properly and not mess up a perfectly good rudder.
 

norcalsail

Active Member
My sail has the grommet at the tack but only sail clip holes on the front edge. This can be seen in the picture Andy provided. The white sail clip at the top of the image is attached to what I assume is a weaker (?) grommet. I want to get a reinforced grommet like Andy's to add a similar cunningham. There is a shop down in Sausalito that gave me a quote of 20 to 50 dollars to add one so I thought that was a good deal and it might help me keep up with these guys. By the way, Eyeper and I had a great time sailing Tomales last Saturday. Some of my adjustments seemed to help-still couldn't keep up with him though.
 
The communication about this has been sparse. I race a fair amount and had never heard of the idea being proposed. I think it is to make the blade almost vertical if you want - similar to a Laser. I know World Sailing will need to approve the change but I don't know when they would be reviewing the change. It will take some skill to drill the hole properly and not mess up a perfectly good rudder.
I posted the original question - and it looks like nobody has yet followed the new ?rule? regarding the rudder. Again, I"m new to the class - must World Sailing approve the new rule before us Sunfish racers implement it on our boats? Has anybody on here modified their rudder to comply with the new rule - which I would also believe would cause the rudder to be more vertical? Thanks!
 

beldar boathead

Well-Known Member
My sail has the grommet at the tack but only sail clip holes on the front edge. This can be seen in the picture Andy provided. The white sail clip at the top of the image is attached to what I assume is a weaker (?) grommet. I want to get a reinforced grommet like Andy's to add a similar cunningham. There is a shop down in Sausalito that gave me a quote of 20 to 50 dollars to add one so I thought that was a good deal and it might help me keep up with these guys. By the way, Eyeper and I had a great time sailing Tomales last Saturday. Some of my adjustments seemed to help-still couldn't keep up with him though.
What kind of boat is Eyeper Sailing?
 

beldar boathead

Well-Known Member
You won’t be able to keep up with a Laser until it’s blowing 20 or so. At that point if you can hike hard you will go the same speed upwind but he’ll go faster offwind.

The Cunningham is useful for de powering when it gets windy. Otherwise you won’t need to use it. It’ll help you depower when it hits perhaps 12-14 knots and more.
 

Eddie_E

Member
It's possible to notch the bottom leading edge of the rudder (in the cassette) to change the angle 10 degrees or so. You do have to plug and re-drill the hole for the tiller strap to get the angle back to normal. Drilling the hole isn't hard all you need to do is tighten the 2 rudder strap bolts enough to keep the holes parallel. drill half way from the right and half way from the left. Drilling only 3/8 deep from each side will not show a 3 degree error where they intersect because it's too short of a distance, I.E. self correcting.
It is worth the effort for a 10~15 degree reduction. it won't make you miraculously fast, but it takes some side load off the tiller. That reduced side force and good body positioning will get you to a point with almost no side load on the tiller while sailing. I've been sailing with roughly 108 degrees for about a year. Don't tell World Sailing, as I know they live in fear of an old 200 lb. sailor in a 1973 Sunfish winning the worlds. ;)
 
It's possible to notch the bottom leading edge of the rudder (in the cassette) to change the angle 10 degrees or so. You do have to plug and re-drill the hole for the tiller strap to get the angle back to normal. Drilling the hole isn't hard all you need to do is tighten the 2 rudder strap bolts enough to keep the holes parallel. drill half way from the right and half way from the left. Drilling only 3/8 deep from each side will not show a 3 degree error where they intersect because it's too short of a distance, I.E. self correcting.
It is worth the effort for a 10~15 degree reduction. it won't make you miraculously fast, but it takes some side load off the tiller. That reduced side force and good body positioning will get you to a point with almost no side load on the tiller while sailing. I've been sailing with roughly 108 degrees for about a year. Don't tell World Sailing, as I know they live in fear of an old 200 lb. sailor in a 1973 Sunfish winning the worlds. ;)
Eddie, thanks for the reply. Any chance that you have photos???
 

Becool44

New Member
I have always thought the rudder shape and angle should be improved. A more vertical angle and a more elliptical profile would improve performance, and the more vertical angle would reduce wear and tear on both hardware and arms.

It would be cool to build an experimental rudder and do some real-world testing. Keep the surface area about the same, and perforate the top pegboard-style, to test various angles. Perhaps start with an old Hobie Cat rudder with a better shape.
 

Eddie_E

Member
I have a nice piece of Sapele that will be a rudder by Spring time. My current plan is to reduce the rake another 8 degrees and increase the volume only 5% or so. I'm not going to the full 90* angle, just based on my experience with another boat. A small amount of rake keeps the tiller from rounding up hard if you have to dive forward to use the QR lever on the gooseneck or fix something real quick.
 

Wavedancer

Upside down?
Staff member
An historical note that is relevant to this thread.
About ten years ago the Class seriously considered allowing a modification to the rudder blade. Test blades were made and tried out. Ultimately though, the modified blade was not legalized.
Here is a link to that discussion; it is 'hidden' on the current forum.
Sunfish Rudder Discussion
 
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Eddie_E

Member
I have a few thoughts on that old thread. First is that trying to cover up bad trim should not be the goal, as mentioned by Bill. However, with proper trim, it has a nice benefit. The idea that it's too expensive to glue a dowel into a hole and re-drill is silly. If you can't afford a $1 dowel, just cut off a piece of a tree branch and glue it in. I would guess it's also true that we don't need as much rudder area as a Laser, even though both have roughly 76 sq/ft of sail area. The lateen rig is balanced better. Again, my best guess is the current wood rudder re-drilled at a 105~108 degree angle is as good as it gets.
 

altair

Member
World Sailing needs to approve for it to be legal. Until that happens I doubt racers will make the change.
I thought this new rudder rule 3.3.3 was approved by the class at the 2018 worlds? Surprised there are no pictures or instructions on how to make the change. Seems it would be very helpful to control weather helm.
 

beldar boathead

Well-Known Member
I thought this new rudder rule 3.3.3 was approved by the class at the 2018 worlds? Surprised there are no pictures or instructions on how to make the change. Seems it would be very helpful to control weather helm.
World Sailing needs to approve it. The class can’t change the rules without WS approval. Haven’t heard status.
 
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