Open space between panels.

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  • 24 Nov 2019 10:15
    Reply # 8136827 on 8125317
    Anonymous member (Administrator)

    Timothy,
    I don’t have a clue about whether the gap between panels does any harm or not. I just know that Roger Taylor has covered thousands of miles in his Mingming II. The gaps between the four lower panels are clearly visible in that rig (the upper section appears to be in one piece? ). Mingming II seems to perform all right, as most boats with cambered sails do.

    However, lack of floor space is not an excuse for using separate panels.  One will anyway need floor space for lofting one full panel, and with that space available, one can also do the sewing. If done right, just about all sewing is done along an edge, so there is no need for rolling up big bundles of canvas to pass it under the sewing machine. Making my 35sqm sail for my Ingeborg in my crowded, little living-room shouldn’t be possible, but it worked well. Sewing was no problem at all. It was more a question of getting the lofting right and accurate. Measure twice  -  cut once!
    Good luck!

    Arne

        

  • 24 Nov 2019 02:35
    Reply # 8136660 on 8125317

    Granted, extruded metal battens are invariably chosen over bamboo in the modern industrialised world, just as synthetic fabric is genefally shown preference over vegetable fibre cloth.

    Advance in design accompanying the tech changes allows dead straight battens to slip into pockets, thus helping to ensure a pressure membrane. 

  • 22 Nov 2019 04:27
    Reply # 8134253 on 8132067
    Anonymous wrote:

    Yes I have tried separate panels tied and laced individually to bamboo battens, and very soon decided that it was a good idea to  rather fill the gap with sailcloth.

    Convenience in handling of smaller pieces of sail loses relevance once a performance comparison is made with one offering a 'cleaner' flow over the filled area.


    Well that depends on how you connect the panels... it is possible to do it very smoothly and even without any gaps. If you are using bamboo, then by it's very nature the joining is likely to be gappy and probably uneven. Aluminium is a much more suitable material for battens in most western countries..
    Last modified: 22 Nov 2019 04:31 | Anonymous member
  • 21 Nov 2019 01:10
    Reply # 8132067 on 8125317

    Yes I have tried separate panels tied and laced individually to bamboo battens, and very soon decided that it was a good idea to  rather fill the gap with sailcloth.

    Convenience in handling of smaller pieces of sail loses relevance once a performance comparison is made with one offering a 'cleaner' flow over the filled area.

  • 20 Nov 2019 17:50
    Reply # 8131407 on 8126747
    Anonymous wrote:
    Anonymous wrote:

    Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 


    Sure, I've made five sails like that to date and I'm using the method for LCB's main. However it's a lot more work and I see little point in doing it unless the sail is to big to handle in the space you have.
    Work space is what got me thinking about this.  
  • 18 Nov 2019 04:53
    Reply # 8126747 on 8125317
    Anonymous wrote:

    Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 


    Sure, I've made five sails like that to date and I'm using the method for LCB's main. However it's a lot more work and I see little point in doing it unless the sail is to big to handle in the space you have.
  • 17 Nov 2019 17:28
    Reply # 8125919 on 8125888
    Anonymous wrote:
    Anonymous wrote:

    Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 


    see: this thread

    It is quite long but discuses it both theoretically and practically (someone has tried it or is in the process of doing so)


    I had just found this! Thanks
  • 17 Nov 2019 16:44
    Reply # 8125888 on 8125317
    Anonymous wrote:

    Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 


    see: this thread

    It is quite long but discuses it both theoretically and practically (someone has tried it or is in the process of doing so)


  • 17 Nov 2019 14:23
    Reply # 8125810 on 8125483
    Anonymous wrote:

    But then I always wonder at the way an aircraft wing separates on landing and takeoff. The big gaps in the aerofoil does not seem to detract from the lift characteristics of the foil, maybe it even helps? But that is a different type of separation to what we are talking about.

    Thanks David, 

    This is kind of what I was thinking about. Each chambered panel being its own little sail, all working together.

    I'm making a 10 sqm  sail for a small (~4m) boat. I may experiment and find out. 

    Last modified: 17 Nov 2019 14:24 | Anonymous member
  • 17 Nov 2019 07:25
    Reply # 8125483 on 8125317
    Anonymous wrote:

    Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 

    More knowledgeable than me will probably respond. I think this has been tried and discussed in these forums. It seems to me that the reason for going to cambered panels is to improve the overall aerodynamic efficiency of the sail, so leaving gaps between the panels might negate any gain made by going to a cambered panel sail. Having also being involved in the build of two large cambered panel junk sails I can't see that the work involved in setting the sail panels up for lacings, or whatever fastening system is to be used, can be any significant saving in labour over building the sail with the batten pockets incorporated as part of the process of joining the individual sail panels together..

    But then I always wonder at the way an aircraft wing separates on landing and takeoff. The big gaps in the aerofoil does not seem to detract from the lift characteristics of the foil, maybe it even helps? But that is a different type of separation to what we are talking about.

    Last modified: 17 Nov 2019 07:39 | Anonymous member
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