Daggerboard Placement
- Thread starter Zorro
- Start date
supercub
Member
Zorro,
The '92 manual indicates that the short side is forward (on the Barrington Board). A copy can be found in the files section of Yahoo Sunfish Sailor (http://groups.yahoo.com/group/sunfish_sailor/). I sail with the long end forward (Barrington Board) and can't tell any difference. I do seem to point a little higher than a friend with the new Composite Daggerboard (long edge forward due to airfoil shape). We keep trading places during the races, so.... You sound like you may have an older round board from a pre '71 SF. Try it both ways and see if you can tell a difference (pointing higher maybe). If you can, that's the way it should go for you. Have fun and Good Luck.
The '92 manual indicates that the short side is forward (on the Barrington Board). A copy can be found in the files section of Yahoo Sunfish Sailor (http://groups.yahoo.com/group/sunfish_sailor/). I sail with the long end forward (Barrington Board) and can't tell any difference. I do seem to point a little higher than a friend with the new Composite Daggerboard (long edge forward due to airfoil shape). We keep trading places during the races, so.... You sound like you may have an older round board from a pre '71 SF. Try it both ways and see if you can tell a difference (pointing higher maybe). If you can, that's the way it should go for you. Have fun and Good Luck.
I have always been curious about this. 
The Sunfish Bible has a diagram on p.27 with all four boards and the only obvious placement is the Racing board.
On p.208 is a photo of the wood boards. The caption says,
" All boards are standing in the correct position for the daggerboard trunk. The
edge is placed forward (toward the bow) using the 'new' and Barrington boards. The 'old' board has the long edge forward for best overall performance".
There's two edges - which edge Was this an editor's oversight and should it have said "short edge" for the New and Barrington boards? That's how I read it anyway.
To make matters more confusing everyone who comments seems to have a different opinion and practice they swear by.
There's got to be definitive instructions backed up by quantifiable research. Does anyone have the design history for the boards. 
Maybe the owner's manual should just say to try it either way and use what you like . Is there a Vanguard person here who can say absolutely positively what's correct?
The Sunfish Bible has a diagram on p.27 with all four boards and the only obvious placement is the Racing board.
On p.208 is a photo of the wood boards. The caption says,
" All boards are standing in the correct position for the daggerboard trunk. The
edge is placed forward (toward the bow) using the 'new' and Barrington boards. The 'old' board has the long edge forward for best overall performance".There's two edges - which edge
Was this an editor's oversight and should it have said "short edge" for the New and Barrington boards? That's how I read it anyway.To make matters more confusing everyone who comments seems to have a different opinion and practice they swear by.
There's got to be definitive instructions backed up by quantifiable research. Does anyone have the design history for the boards. Maybe the owner's manual should just say to try it either way and use what you like . Is there a Vanguard person here who can say absolutely positively what's correct?
supercub
Member
Megan, Zorro,
You are among the majority of SF sailors confused as to which edge of the board should be forward. The history of the boards as given in the SFB, The old round board, the Shadow board (too much sweep, area too small, dropped from line up), the Barrington (larger, less sweep) and the new Composite board (largest area, airfoil (hydro?) shaped). The last paragraph on p. 209 of the SF Bible starts a discussion on this subject (which you have no doubt already have read). ..."There is no exact answer for this question"..."too many variables", ..."major regattas examined"..., ..."Barrington board...swept back edge forward, ...old board...straight edge forward"...
The next little bit is my own opion. Without a test tank, time and lots of money, I doubt if the question will ever be answered scientifically (or to everyones satisfaction).
On the Barrington board both edges are tapered equally (first 1-1/4"), so the entry and exit of the blade through the water are basically equal. The difference in edge length and sweep back changes the center of pressure (or effort) forward and aft depending on which edge is forward. This change is minimal. The sweep on the Barrington board top to bottom is only an inch, so the center of pressure change would be about 1" (1/2" either way). If the leading edge were rounded (as many do legally with putty, fiberglass and paint) (SFB p. 44 picture, p.45-48 disscusion) and the board is maxed out in thickness, then maybe a more diffinative "feel" in the board would be observed as this would move (slightly) the center of pressure closer to the leading (rounded) edge. Lots of work for just a little percieved gain. The only way to know for sure (for your personal sailing style) is to experiment over time with two boards, one with the long edge rounded, the other with the sweept edge rounded. The one that works best with your style of sailing would be the one to use (but probably not legal for racing if you made it). My suggestion, take a stock wood board, pick an edge you prefer to always place forward and learn to sail with the board that position (thats what I have done). Or get the new board ($$$) and the decision is made for you. Good Luck.
You are among the majority of SF sailors confused as to which edge of the board should be forward. The history of the boards as given in the SFB, The old round board, the Shadow board (too much sweep, area too small, dropped from line up), the Barrington (larger, less sweep) and the new Composite board (largest area, airfoil (hydro?) shaped). The last paragraph on p. 209 of the SF Bible starts a discussion on this subject (which you have no doubt already have read). ..."There is no exact answer for this question"..."too many variables", ..."major regattas examined"..., ..."Barrington board...swept back edge forward, ...old board...straight edge forward"...
The next little bit is my own opion. Without a test tank, time and lots of money, I doubt if the question will ever be answered scientifically (or to everyones satisfaction).
On the Barrington board both edges are tapered equally (first 1-1/4"), so the entry and exit of the blade through the water are basically equal. The difference in edge length and sweep back changes the center of pressure (or effort) forward and aft depending on which edge is forward. This change is minimal. The sweep on the Barrington board top to bottom is only an inch, so the center of pressure change would be about 1" (1/2" either way). If the leading edge were rounded (as many do legally with putty, fiberglass and paint) (SFB p. 44 picture, p.45-48 disscusion) and the board is maxed out in thickness, then maybe a more diffinative "feel" in the board would be observed as this would move (slightly) the center of pressure closer to the leading (rounded) edge. Lots of work for just a little percieved gain. The only way to know for sure (for your personal sailing style) is to experiment over time with two boards, one with the long edge rounded, the other with the sweept edge rounded. The one that works best with your style of sailing would be the one to use (but probably not legal for racing if you made it). My suggestion, take a stock wood board, pick an edge you prefer to always place forward and learn to sail with the board that position (thats what I have done). Or get the new board ($$$) and the decision is made for you. Good Luck.
Tim Polaski
79429
If I had to choose, I would sail with the long edge forward, and I would taper the trailing edge of the short side (within the allowable tolerances of course) and I would put a little more elliptical shape in the forward edge. This would replicate the more typical shape of the plastic board and other boards in other classes.
Supercub, you speak about the subtle shifts in center of effort. The fact that there is a difference is exactly my point. You haven’t answered the question. All the rhetoric only describes in more detail the problem. Which direction is optimal? And where are the numbers to back it up? The controversy seems to undermine the credibility of past company set up instructions.
I am assuming you don’t officially represent the Sunfish companies of past or present when you stated, "There is no exact answer for this question"..."too many variables" and, “ Without a test tank, time and lots of money, I doubt if the question will ever be answered scientifically”. I find it hard to believe some intelligent thought and testing didn’t go into the dagger board design. If not originally then for subsequent modifications. I am astounded that the perception both here and in the SB articles is that equipment was not actually designed on hydrodynamic principals, but rather (as Grandma use to say) Kentucky Windage. That it has been left up to the user to draw on their own engineering prowess or seat of the pants guesstimating to refine the design so that it’s seriously functional.
You make it sound as if the dagger board was developed by a committee of interior decorators not a boat designer or engineer. I struggle to accept the idea a company who is purported to have produced more of this boat than any other boat sold in the past 50 odd years uses such a garage shop approach to design a piece of technical equipment. Maybe Vanguard has reached the same conclusion and discounted previous builder’s lack of engineering effort by subtly discontinuing and distancing themselves from the old and bringing on the new, truly engineered, dagger board. That would certainly make this discussion a moot point for owners of the new board. Only the rest of us ‘old’ board owners are left out in the cold. Sounds to me like Tim has the right answer for anyone wanting performance form a wood board. Reshape it to the new board design albeit it’s shorter length. Why then would this not be Class Legal? It would meet all criteria save one, the subjective acceptance of the Class.
I understand the focus SB articles place on personal technique and style for sailing the boat. It’s just that I, and especially those folks restricted by Class Rules, must rely on the company for sound equipment design and instruction for it’s proper application. I don’t want to adapt to, possibly, the least desirable situation, as you have suggested. I want to tune the boat to it’s peak performance level and then add my skills knowing the boat is all it can be.
Where’s Vanguard on this? Can’t they say definitively? Are they wearing blinders and leave customer support beyond warranty to an amateur free for all? 
I am assuming you don’t officially represent the Sunfish companies of past or present when you stated, "There is no exact answer for this question"..."too many variables" and, “ Without a test tank, time and lots of money, I doubt if the question will ever be answered scientifically”. I find it hard to believe some intelligent thought and testing didn’t go into the dagger board design. If not originally then for subsequent modifications. I am astounded that the perception both here and in the SB articles is that equipment was not actually designed on hydrodynamic principals, but rather (as Grandma use to say) Kentucky Windage. That it has been left up to the user to draw on their own engineering prowess or seat of the pants guesstimating to refine the design so that it’s seriously functional.
You make it sound as if the dagger board was developed by a committee of interior decorators not a boat designer or engineer. I struggle to accept the idea a company who is purported to have produced more of this boat than any other boat sold in the past 50 odd years uses such a garage shop approach to design a piece of technical equipment. Maybe Vanguard has reached the same conclusion and discounted previous builder’s lack of engineering effort by subtly discontinuing and distancing themselves from the old and bringing on the new, truly engineered, dagger board. That would certainly make this discussion a moot point for owners of the new board. Only the rest of us ‘old’ board owners are left out in the cold. Sounds to me like Tim has the right answer for anyone wanting performance form a wood board. Reshape it to the new board design albeit it’s shorter length. Why then would this not be Class Legal? It would meet all criteria save one, the subjective acceptance of the Class.
I understand the focus SB articles place on personal technique and style for sailing the boat. It’s just that I, and especially those folks restricted by Class Rules, must rely on the company for sound equipment design and instruction for it’s proper application. I don’t want to adapt to, possibly, the least desirable situation, as you have suggested. I want to tune the boat to it’s peak performance level and then add my skills knowing the boat is all it can be.
Where’s Vanguard on this? Can’t they say definitively? Are they wearing blinders and leave customer support beyond warranty to an amateur free for all?
Old Geezer
Member
Megan said:
Hey - that would explain a lot about the design of the Sunfish. Clearly nobody with a modicum of boat design training could create such a bizarre little toy.
The debate about wooden daggerboards is moot. They are all bad whether backwards, forwards or upside down. If you want to race at all seriously you need the "new" plastic daggerboard. I say "new" in quotes because it's only been available for what, 12 years or more now?
Those of you still sailing with bits of plank sticking out the bottom of your boat are doomed to fail. Anyone who disagrees is welcome to challenge me to a 5 race match race series for a purse of $1000 - you can use your hunk of timber with your bits of putty stuck on it any way up you like (as long as it complies to the class rules seemingly written by that same interior designer) -- I will use a real daggerboard.
supercub
Member
Megan,
You are correct, I do not represent Vanguard, Alcort or any of the previous builders of the Sunfish.
The statments in quotes in the first paragraph of my previous reply are from the SF Bible (pages noted).
You were close on the interior designer guess, Cortland Heyniger and Alex Bryant were origanally house builders. Chapter 1 (p-14) in the SFB gives you a history of the Sailfish/Sunfish Design.
The wood daggerboards developed (I believe, nobody seems to know for sure) over the years were by trail and error (the Shadow version didn't work, so was eliminated) and probably a little "TLAR" (That Looks About Right). The "new" composite board at least was designed with help from some engineers and those with experience in watercraft (page 28, SFB), tested and tried for a time before being marketed in 1993.
As far as my observations noted in paragraph 3, they are from sailing the SF since 1963, building and flying model aircraft since about the same time, studying aerodynamics in college, flying full size aircraft and racing model boats over the years. Similar principles apply to both aircraft and watercraft (water being denser than air, smaller surfaces are used in water for similar effect). In experimenting with different wings on the same model plane (straight verses tapered) I was able to see how the plane would respond. By using the 3 different wood boards (Original, Shadow (I still have a beat-up one) and Barrington), I was able to see differences in them, I prefer the Barrington. As far as seeing which edge forward was better, I can not see a difference, but then I am not looking for the last little bit of speed from my SF (the club races are somewhat casual and of mixed fleet). And no, I have not tried the "new" composite daggerboard yet (although a sailing buddy has the "new" board, I may swap boards for a race, who knows). As Old Geezer says, if you want to race seriously, get the "new" board.
Bottom line to the sucess of the SF (in my opinion) was that it was fairly inexpensive, simple to rig and operate and easy to right after capsize and was and is loads of fun. I do not believe that it was intended to be a serious racing machine, just something that was fun on the water.
You are correct, I do not represent Vanguard, Alcort or any of the previous builders of the Sunfish.
The statments in quotes in the first paragraph of my previous reply are from the SF Bible (pages noted).
You were close on the interior designer guess, Cortland Heyniger and Alex Bryant were origanally house builders. Chapter 1 (p-14) in the SFB gives you a history of the Sailfish/Sunfish Design.
The wood daggerboards developed (I believe, nobody seems to know for sure) over the years were by trail and error (the Shadow version didn't work, so was eliminated) and probably a little "TLAR" (That Looks About Right). The "new" composite board at least was designed with help from some engineers and those with experience in watercraft (page 28, SFB), tested and tried for a time before being marketed in 1993.
As far as my observations noted in paragraph 3, they are from sailing the SF since 1963, building and flying model aircraft since about the same time, studying aerodynamics in college, flying full size aircraft and racing model boats over the years. Similar principles apply to both aircraft and watercraft (water being denser than air, smaller surfaces are used in water for similar effect). In experimenting with different wings on the same model plane (straight verses tapered) I was able to see how the plane would respond. By using the 3 different wood boards (Original, Shadow (I still have a beat-up one) and Barrington), I was able to see differences in them, I prefer the Barrington. As far as seeing which edge forward was better, I can not see a difference, but then I am not looking for the last little bit of speed from my SF (the club races are somewhat casual and of mixed fleet). And no, I have not tried the "new" composite daggerboard yet (although a sailing buddy has the "new" board, I may swap boards for a race, who knows). As Old Geezer says, if you want to race seriously, get the "new" board.
Bottom line to the sucess of the SF (in my opinion) was that it was fairly inexpensive, simple to rig and operate and easy to right after capsize and was and is loads of fun. I do not believe that it was intended to be a serious racing machine, just something that was fun on the water.
Old Geezer said:
Hate to admit this, but OG is right on target. No serious racer uses a wooden board anymore. And if you are not racing, enjoy your wooden board any way you wish.
mike4947
Member
And to add to the design question. The first Sunfish lines were drawn out on chalk on a garage floor. Remember Al & Cort were ice boat builders that "graduated" to the Sailfish, and then to the Sunfish. One of the help schetched out the lines for the Fish.
Also the "infamous" shadow board was the creation of some moron who said, "let's make the Sunfish board shaped like the mini fish board, it's more modern looking". NO design or testing what so ever.
The Barrington board was developed, or at least tested at Barrington RI, hence the name.
Also the "infamous" shadow board was the creation of some moron who said, "let's make the Sunfish board shaped like the mini fish board, it's more modern looking". NO design or testing what so ever.
The Barrington board was developed, or at least tested at Barrington RI, hence the name.
supercub
Member
Wavedancer,
I agree with you and OG, If someone insists on using a wood board to race, they can modify it all they want and still come up short. They would have to optimize everything else on their SF, be very sensitive to any changes in performance to realize what, if any, difference the board placement makes.
For someone just sailing for fun, it does not matter which edge is forward (except for looks, but who has their head underwater looking?).
Mike,
Thanks for the added info.
I agree with you and OG, If someone insists on using a wood board to race, they can modify it all they want and still come up short. They would have to optimize everything else on their SF, be very sensitive to any changes in performance to realize what, if any, difference the board placement makes.
For someone just sailing for fun, it does not matter which edge is forward (except for looks, but who has their head underwater looking?).
Mike,
Thanks for the added info.