Changing Rudder Pivot Point

Thread starter #1
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

Active Member
#2
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

Active Member
#3
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
 
Last edited:

L&VW

Well-Known Member
#5
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
#6
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
#7
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

Active Member
#8
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
 
Last edited:

andyatos

Active Member
#9
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
 
#10
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
#12
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

Active Member
#13
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
#14
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?
 

Attachments

beldar boathead

Well-Known Member
#15
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.
 
#16
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.
 
Thread starter #17
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
#19
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?
 
Top