Hi All, Just for those of you who are curious about sail sizes: That calculator is pretty cool, but it understates the real LP% by a small amount. The sail has a curved surface, but the calculator is computing the shortest straight-line distance between two points on the curved surface. This kind of measurement is referred to as "geodesic" The true LP, when measured on the sail itself, will always be slightly bigger than a geodesic-space calculation indicates. Sail design software computes dimensions along the curved surface of the sail. BTW, according to the original sailplan that Jerry so generously sent me, there was an 80%-ish LP Heavy wind jib. Also a 109%, which is a great, versatile working jib for the M17. Regards,Judywww.HydeSailsDirect.com On Sat, Oct 22, 2016 at 2:04 PM, John Schinnerer <john@eco-living.net> wrote:
Tidying up my sails, finally doing some measuring...
My "small" jib is not the 109% standard or working M17 jib, it's quite a bit smaller. Here's one calculator I found: http://sailingfortuitous.com/apps/jibcalc.html
This and other similar formulas found online put it at about 81-82% (luff 189", leach 160", foot 76"). In between a working jib and a true (like 60-65%) storm jib.
Also played with the outhaul method shown in that video I posted recently. Really a good idea AFAICT. Works as clew strap and outhaul both; automagically balances the angle of pull on the clew.
And, makes it much easier to move that same outhaul line to a different reef grommet - no need to tie or untie any knots on flapping sail in bouncing boat. Just loose the outhaul, pull out of current grommet & block, route back through new grommet & block & make fast. With a boltrope or slug footed sail of course. This would be a Very Bad Idea on a loose-footed main...!
cheers, John S.
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
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