Fast way to make cambered sails

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  • 03 Jun 2011 14:30
    Reply # 612050 on 611677
    Gary Pick wrote:
    David Tyler wrote:
    Jeff McFadden wrote:
    David,
    Do you sew the two panels together before you sew the tucks down, or do you sew the tucks down first?
    Jeff
    The  tucks are sewn first.Then you have two straight edges to sew together, which are easy to manage, whether you make a lap joint or place one panel on top of the other, as Arne does.

    Hi David, where is your article on doing it this way? I realised I'm being a bit one eyed on this and I shouldn't be.

    It's okay I found it.:D
  • 03 Jun 2011 00:01
    Reply # 611677 on 611551
    David Tyler wrote:
    Jeff McFadden wrote:
    David,
    Do you sew the two panels together before you sew the tucks down, or do you sew the tucks down first?
    Jeff
    The  tucks are sewn first.Then you have two straight edges to sew together, which are easy to manage, whether you make a lap joint or place one panel on top of the other, as Arne does.

    Hi David, where is your article on doing it this way? I realised I'm being a bit one eyed on this and I shouldn't be.
  • 02 Jun 2011 20:19
    Reply # 611551 on 611350
    Jeff McFadden wrote:
    David,
    Do you sew the two panels together before you sew the tucks down, or do you sew the tucks down first?
    Jeff
    The  tucks are sewn first.Then you have two straight edges to sew together, which are easy to manage, whether you make a lap joint or place one panel on top of the other, as Arne does.
  • 02 Jun 2011 16:48
    Reply # 611380 on 605377
    Anonymous member (Administrator)

    Stavanger, Thursday

                                    Barrel-cut versus Tyler-tucks

    David,

    I looked up the sketches about your tuck method and the Tom Thumb sail plan. The method no doubt is easy to understand involving no rocket science whatsoever. The knuckles you mention will be no problem, just as on Badger.

    (..I too was concerned about sharp corners in the sail when making hinges in the battens for Malena, 20 years ago. No problems there either; the horizontal curves in the panels were nice and smooth...)

    I also noticed on Badger’s sail (similar tuck method) in 2006 that the vertical curve from batten to batten was closer to trapese-shaped than "my" sails. In a way you get closer to the shelf foot method without all that extra brainwork, cutting and sewing. So this looks good and will probably sell better too.

    So why don’t I jump over to the "Tyler-tucks" from my present "barrel-cut" method?

    1) A bit from laziness of course – I am so familiar with my way of doing it now – and I don’t have to sell sails. But not only because of that:

    2) The barrel cut method is still quicker to make for an amateur and without any folds getting in the way when assembling the batten panels with my household sewing machine (no walking foot). All you need extra is a nice long spline to produce those "barrel side" curves.

    3) I find it hard to believe that the small wrinkles that one may get along the battens with the barrel cut method will slow the boat noticeably down. I notice that Johanna is the only boat in Stavanger which really has these wrinkles. This summer I’ll stretch the sail a bit more along the battens to get rid of them. Then I’ll check how much influence this has on the max camber.

    4) At the max camber point a vertical curve through a barrel cut panel will be more rounded, not trapeze-like at all. This  makes it easy to think that the camber varies a lot and that the sail therefore will be less efficient. However when moving towards the luff or leech, these vertical curves will get closer and closer to the trapeze shape. This I noticed as early as on my first test panel in 1993 (see NL30, p.22). My hunch is therefore that the wind will enter a sail at pretty constant angle of attack along the luff and also leave it that way. If my hunch holds water, then the shape of the barrel cut panel should be just as efficient as one made with tucks or with the shelf foot method.

    Sooo, until someone with a similar boat as Johanna comes over and sail in rings around us with their clever sails; wings, split-rigs, shelf foot method or whatever, I'll stubbornly stick to what I have.

    Arne

    PS: These days I put another layer of 2-pot varnish on Broremann’s new mast every day. I ache to get a sail in Broremann soon...

    Last modified: 02 Jun 2011 19:05 | Anonymous member (Administrator)
  • 02 Jun 2011 16:03
    Reply # 611350 on 611239
    Deleted user
    David Tyler wrote:Arne,
    Can you have a look in the "online file store" /Drawings/David's doodles, at "tucked panel for Tom Thumb 24" and "how to sew a tuck"?
    You will see that the top and bottom edges of the panel consist of three straight lines, with the tucks positioned where these lines meet. The angle included in the tuck is the same as the angle between the two edges either side of the tuck. Looking at "how to sew a tuck", the panel is folded so that the two edges either side of a tuck lie on top of each other, and then  you sew at right angles to the edge, from the edge towards the fold, curving a little bit towards the end, to soften the effect. Then you open out the panel, and sew down the fold of cloth that is standing up, just like sewing a flat seam. Because you have sewn the tuck at right angles to the two edges, the finished edge of the panel has to be a straight line. In theory, the camber produced has two "corners" between three straight lines, just as if you had put two hinges into a batten. But in practice, the cloth does not want to lie in three straight lines, it wants to take a curve, and if there is any suggestion of there being corners, it is only at the inner ends of the tucks. The effect should be the same as if you use some broad-seaming on vertical cloths, as I did on Badger's sails, which you have seen. The shape will be the same, but produced in a different way.
    David. 

    David,
    Do you sew the two panels together before you sew the tucks down, or do you sew the tucks down first?
    Jeff
  • 02 Jun 2011 13:52
    Reply # 611280 on 611198
    Gary King wrote:Thats a great thread Gary. I had forgotten about it, I would have been in Central coast NSW the whole time being preoccupied. That cantankerous sailmaker (of pointy sails) was a laugh. 
    You used batten loops all over. Naughty boy..
    I used batten loops because I'm going to use bamboo battens and I felt they would go mouldy in pockets. The sail will be lashed to the yard and boom. Fingers crossed it will all work perfectly.
  • 02 Jun 2011 12:12
    Reply # 611239 on 605377
    Arne,
    Can you have a look in the "online file store" /Drawings/David's doodles, at "tucked panel for Tom Thumb 24" and "how to sew a tuck"?
    You will see that the top and bottom edges of the panel consist of three straight lines, with the tucks positioned where these lines meet. The angle included in the tuck is the same as the angle between the two edges either side of the tuck. Looking at "how to sew a tuck", the panel is folded so that the two edges either side of a tuck lie on top of each other, and then  you sew at right angles to the edge, from the edge towards the fold, curving a little bit towards the end, to soften the effect. Then you open out the panel, and sew down the fold of cloth that is standing up, just like sewing a flat seam. Because you have sewn the tuck at right angles to the two edges, the finished edge of the panel has to be a straight line. In theory, the camber produced has two "corners" between three straight lines, just as if you had put two hinges into a batten. But in practice, the cloth does not want to lie in three straight lines, it wants to take a curve, and if there is any suggestion of there being corners, it is only at the inner ends of the tucks. The effect should be the same as if you use some broad-seaming on vertical cloths, as I did on Badger's sails, which you have seen. The shape will be the same, but produced in a different way.
    David. 
  • 02 Jun 2011 11:34
    Reply # 611232 on 605377
    Anonymous member (Administrator)

    Stavanger, Thursday

                                  Tucks, why, where and how

    David,

    a couple of days ago you wrote to Gary King:

    "The professional sailmaker who is making Graham Cox's sail quickly spotted that the tucked panel I drew is the quickest way to get the camber in the right place without fighting wrinkles or other speed-sapping difficulties. For a professional, speed equals making money rather than losing it. 

     So I would say: a single cloth per panel, with camber added by tucking, and pockets added as part of seaming panels together, is the quickest way." 

    I am quite a bit confused on how you fit these tucks. Are they an addition to the rounding along the battens just to remove wrinkles or are they producing the whole camber without cutting rounding first? Maybe you have described it somewhere, but I can’t find it.

    Arne

    Last modified: 02 Jun 2011 11:43 | Anonymous member (Administrator)
  • 02 Jun 2011 09:39
    Reply # 611198 on 605377
    Deleted user
    Thats a great thread Gary. I had forgotten about it, I would have been in Central coast NSW the whole time being preoccupied. That cantankerous sailmaker (of pointy sails) was a laugh. 
    You used batten loops all over. Naughty boy..
  • 02 Jun 2011 08:34
    Reply # 611175 on 605377
    I would use the barrel cut..which I did. it really isn't hard to do. Though I did get a bit confused from time to time. Here's the WBF thread I did on it.
     
    http://forum.woodenboat.com/showthread.php?118979-How-to-build-a-cambered-Junkrig-sail.&highlight=how+to+make+a+junk+rig+sail
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