Thinking about making my own, as I have a source for a very similar foil shaped extrusion (http://www.titantruckracks.com ($10/ft, 5.5x1.75" x 3/16 gauge 6061 T6 aluminum). Add a SS wire 'pelican striker' truss, and SS threaded rod with a hole drilled through the tip of one end for the wire to run through. attached directly to adjustable plates on bow tangs. Sounds fine, except a little bit of engineering, and catastrophic if it wasn't built right… I also have some 2" 0.125 6061 aluminum tube which would work, and only set me back $3/ft.
Jack at Nacra suggested as a better alternative a floating bow spreader bar, like the Prindle Escape and the Hobie 17 sport conversion (pics below). See that thread here: http://www.thebeachcats.c…opic/topic/15050/start/0. Using the same 2" 0.125 tube (I suspect stronger in this application than the foil shaped stuff), no foil/truss assembly required, as a traditional two-wire bridal is used. The tube only has minor loading in compression from each end where the angle changes (as opposed to an upwards centre pull on a bridal foil). Disadvantage: jib can't come down as low, where the power is preferred, and I might need to recut the 5.8 jib at the bottom. Advantage: simpler to engineer, and if the tube bent or broke (which is unlikely) it wouldn't be catastrophic (ie. dropped mast) just slack in the system and some inwards bow pressure and a limp home.
The height the spreader bar is above the tangs would be compromise between keeping it out of water and keeping jib low as possible.
I have a kind fellow sailor offer me a 5.8 jib, which we are hoping will fit, and I'm willing to take any other dusty, retired parts people might have in a box somewhere!
Appreciate any thoughts,
Tom
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Tom
Nacra 5.5 Uni
(actually a chopped down 18sq)
(soon to be 5.5 sloop)
Northern California
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