Sailboat Daggerboard Attack Angle

Discussion in 'Boat Design' started by BobBill, Jan 13, 2012.

  1. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    Have not measured the max angle of sweep of a Windmill DB but have never had lee helm on one in over 45 years of Windmill sailing. The dimensions of the DB trunk are strictly controlled but I did build one with the upper and lower lengths skewed to maximize the angle of sweep for a lightweight crew. Placement of the stop that prevents the DB from sliding through the trunk also influences the angle of sweep. That directly address your next question about heeling (not healing). Heeling a sailboat moves the CE of the sails outboard, thus light weight crews have more problems with heeling. This introduces a force moment that tends to turn the boat to windward which is called weather helm. In the extreme this induces the dreaded broach, which all will experience sooner or later.

    Experimentation is the key to learning. What we say here is just so much gab and guff until you actually see and understand it personally.

    In 1993, I redesigned the Windmill for the Windmill Class Association so one could be built in composite plywood/epoxy/fiberglass in a female mold. Most new wooden Windmills are built in this design and they are fully competitive in racing with the best fiberglass models. These boats conform to all the class tolerances so are fully legal for racing. The prototype of the composite Windmill is shown here winning the 1995 Southern Championship with me crewing for my son. http://www.bluejacketboats.com/Harbinger R.jpg

    I still consider the Windmill to be at the top (along with a very, very few others) of sailboats that can be built at home and raced successfully by an average family crew. A very responsive and exciting boat to sail, if not for the timid.
     
  2. Doug Lord
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    Doug Lord Flight Ready

    Tom, I raced a Windmill for years-great boat! Don't remember being able to angle the board aft unless it was partially retracted?
     
  3. BobBill
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    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Daggerboard Sweep Angle

    Windmills are by far the simplest faster boats. Thanks for added information. The further back the CE, the further back the board, to a point. The swept back board moves it back in degrees. I think I get it.
     
  4. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    Doug,

    The Windmill DB trunk is long enough to allow quite a bit of movement of the DB, both forward and aft of vertical. One new change in the rules is that the very long DB can be shortened from the tip (up to 10 inches, I think). This apparently has no measurable effect on performance to windward and the old DB was evidently overly long for the need. With much less exposure under the boat, reaching speed should be increased. It does make the boat much more crew friendly and my wife would have gotten many fewer bruises if that had been allowed when I was racing one. The rudder rules have also been redone from the old paddle shape to allow a modern vertical cassette. A kick-up was always part of the rules.
     
  5. Doug Lord
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    Doug Lord Flight Ready

    I always wanted to try a "turboed" 'Mill singlehanded with a trapeze and bigger main-a "contenderized" Windmill. The new rudder sounds great. Are carbon masts allowed now? My last Windmill race was about 1968. Raced the US1(Windmill rip off) in the early 80's. I re-sized my board one glorious day at Little Sabine Bay on Pensacola Beach-had it up as high as I could without it catching on the vang and hit a sandbar wide open. Thought it was deeper.....


    Picture-"Demon" w/o jib about 1967:
     

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  6. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    Saw a few US 1's but never sailed one as we all went Lasers for single handing at the time. Larry Christian of New Hampshire, who built the second of my redesigned Windmills, did fit a trapeze and had a ball with it. The sail area was not quite enough to support a trap off-wind until the wind blew pretty hard but it flew under the right conditions. Don't know if he ever single handed with the trap though. A couple guys did try a spinnaker but the Windmill bow was just too fine for that and a submarine was sometimes the result. In my salad days, I liked to single the 'Mill in planing conditions though. Planing upwind was always a goal although seldom achieved except under the best of conditions.

    What number was your Windmill Doug? My first one was #2316 Don Quixote.
     
  7. Doug Lord
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    Doug Lord Flight Ready

    ------------------------
    Windmill #1568 purchased at a slight discount from Paul Schreck since the stem was slightly wide (but still legal according to him). My brother got Schrecks boat-#604. We went at really hard for awhile. Our "two boat testing" really helped.....

    PS- two regattas that stand out for me were the 1965 Southeastern District Championship in Montgomery, Alabama-I won with 4 firsts and a third. And the 1966 Billy Bowlegs Open Class regatta where I won "line honors" and on corrected against a well sailed Flying Dutchman-that was really cool(and lightair)-still have the newspaper clipping about that. A year or so prior to the Districts I came up with a continuous traveller that ran across the boat just forward of the aft thwart, the main sheet was attached to a bridle at the transom. Paul Schreck said he thought it was a great idea which was a hell of a confidence boost to a 15 year old kid! Both my brother and I read about a new paint called "Super Glide" that was in Popular Mechanics or Popular Science-the stuff was slick! We were advised that it was legal, but at the Districts I was first and my brother was second until the last race when he got a 5th-which made him third overall. We were told there that his 5th saved us both from a protest for the "Super Glide". But as far as we were concerned the training we did -every day for a year ahead of time- is why we were fast. One other one I just remembered: there was a race called the "Dauphin Island Race" which was from Fairhope Al. to the Island. 130 boats entered the time we did and we were the first boats to finish after the cats and scows! And my brother won by a hair(less than one boatlength after 20+ miles).
    PS# 2-My boat was sailed at an all up crew weight of 260lb. We could get away with that because we could out hike almost anybody. Both of us built hiking benches and trained rigourously and it really paid off.
     
  8. tom28571
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    tom28571 Senior Member

    I experimented with Polygo, I think it was called. It is a long chain polymer similar to fish slime that, when wet, was slicker than anything I ever felt. I painted the bottom and rudder and DB with it prior to a district Championship. It rained on the way to the regatta on Lake Norman, NC and the bottom got covered with road grit. I scrubbed it all off but for the DB and rudder. When the DB was laid in the hull bottom it contaminated the bottom and made it impossible to stand and I had to clean that off too. The AYRS made extensive tests and deemed any surface treatment legal since none could be shown to actually reduce frictional drag. Brittan Chance, I think, drilled a series of small holes in the forward bottom of a keelboat and pumped the same stuff into the boundary layer, which was effective in reducing drag so that was ruled illegal. I have used that material when pulling telephone cables through long conduits where it was also very useful. It's also used in piping of powerplants to reduce drag.
     
  9. messabout
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    messabout Senior Member

    More Windmill nostalgia...........I was a member of fleet 47 in Lakeland Fl. We bragged that we were the worlds fastest fleet. We practiced a lot, at least one time each week, sometimes as many as three sessions per week. We would set up short courses and sail a couple of races, then retire to the beach to critique one another. Then out for a couple more races and later critique. That made us all a lot sharper sailors.

    Dennis Fontaine, one of our group, was several times regional champ and a couple times national champ. Other contenders, like Jim Pardee, were plenty good too.

    The most rememberable episode in my Windmill career was at the nationals at the New Orleans Yacht club. There were something like 75 Mills that showed up to fight it out on Lake Ponchatraine. About the third race I got a good start and took the lead when I found a nice long lift. John Dane, the Olympic sailor, was the only one who could catch me. We had the most stirring tacking duel that involved 14 tacks. That was about as much fun as you can have in a little boat. Dane won the duel but I was pretty honored to be on the same water with him, to say nothing of fighting a spirited, and evenly matched duel with an Olympian. I credited my 100 pound daughter for her spectacular and flawless crew work.
     
  10. Doug Lord
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    Doug Lord Flight Ready

    =============
    I knew of John Dane but never met him-about what year was this?
     
  11. messabout
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    messabout Senior Member

    Doug: Mid seventies. I'm too old to remember exactly.
     

  12. Doug Lord
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    Doug Lord Flight Ready

    Thanks- the guy is a great sailor.
     
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