Re: [Sailcut-users] The Big Q: will the triradial panels give me the profile?

[Robert L. <rob...@sa...>]

Mubbets wrote:
> Hi Sailcut users and developers,
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> I have posted a message on the sail profile some time ago. In the mean =
time=20
> I have ordered the book of mr. Marino as adviced and that's a goldmine.=
 It=20
> basically answered my questions, although the profile thing remains a b=
ig of=20
> a leap into the dark.
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> Anyway, behind me is a 20 m role of 4.5 oz. Dacron awaiting to be=20
> transformed into a sail. I have attached the ultimate layout in a jpg f=
ile.
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> One question remains: I have imported the TXT files into Excel to play=20
> around with the data. I have generated quite some XY points to be plott=
ed=20
> onto the cloth (first I will plot them onto low cost material to obtain=
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> optimal cloth usage). I noticed in the datafile that a lot of the panel=
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> sides are quite linear and even fully linear. Only a few of the panels =
have=20
> dX or dY values that exceed my expected accuray of plotting and cutting=
 of 1=20
> mm (and that's when I am not nervous).
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> My basic question is now if I can do with only plotting the corner poin=
ts=20
> (which will reduce the hours I will spend on my knees considerably,=20
> measuring out all the points) in those cases where the panel sides are=20
> basically linear? Will this approach give me the expected sail profile?=
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> Should I see the depth being generated just like in a football or a=20
> buckyball where the panel sides are also linear, but the actual profile=
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> depth is there?
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> Maybe some of you (Robert?) can give me some reassurance before I have =
to=20
> explain the wife about a major screw-up in one of my projects?
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> Thanx! Eric
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Eric,
I cannot read the ascii file (I am using linux) however I will try to
provide guidance.

on normal sails there is little shape in many seams but it is the sum of
all the little dY which give the shape. I know it is not easy to figure
out what to use at the beginning.
Now if all the seams are straight (all dY less than a mm) it is very
likely that you have designed a sail which is either a near perfect cone
or a very flat sail.

Normally a sail has a relatively flat foot, some depth in the middle and
even more depth at the top to accommodate the twist. It is also
essential to have a luff factor which increases as you go up the sail
such that you have a fine foot entry, a fairly full entry in the middle
and a at the top.

--=20
    Regards / Amiti=E9s
       Robert Lain=E9
http://www.sailcut.com   Free CAD for sails and hull
http://sailcut.sourceforge.net  GPL source code
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