Changing Rudder Pivot Point

beldar boathead

Well-Known Member
#21
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.
 
#22
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. ;)
 
Thread starter #23
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???
 
#26
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.
 
#27
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
#28
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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#29
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.
 
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