Main beam waterstays on small foiling tri

Discussion in 'Multihulls' started by revintage, Mar 25, 2019.

  1. Doug Halsey
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    Doug Halsey Senior Member

    It's about 19" (48cm) deck-to-bottom.

    I like the look of your beam attachment as is & don't think you should go out of your way to raise it.

    It's up to you of course. Just another design decision.
     
    revintage likes this.
  2. revintage
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    revintage Senior Member

    Thanks Doug,

    A Tornado´s dolphin strut is ca 24cm from the underside of the beam, with the band attached to the beam at ca 115cm. This is 11,5 degrees.

    A Nacra 18SQ has a 23,5 cm strut at 135cm: 10 degrees.

    So let´s go for 10 degrees

    Using a 26cm strut to get the same angle as the 18SQ DS, the waterstays will be at 23,5cm where they come out of the hull sides, if the stays are attached to the beam at 150cm. Works for me. Have added this to my previous sketch.
     
    Last edited: Mar 28, 2019
  3. revintage
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    revintage Senior Member

    Have dumped the full 90x2mm main beam. Have instead ordered a 3m 110x2mm tube to acta as center of the main beam. The outer 125cm of the main beam will still be 90x2mm and telescoped inside the bigger tube with 0,5m overlap. The 110x2 has 1.85x the torsion and 1.5x the bend figures of the 90x2. Compared to a 4"x0.049" it has twice the torsion and 1.85 the bend figures.

    Question is, could I dump the waterstays on this 100kg and 5.5m wide foiler build?

    jointlock4.png
     
  4. patzefran
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    patzefran patzefran

    Don't use Dyneema waterstays or you will need to retighten at each sailing. I have used Vectran since 2013 for my Strike 15, Strike 20 Tris and now for 2 years on the Dolphin Striker of my Paper Tiger cat, I never need to re-tighten !
     
  5. revintage
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    revintage Senior Member

    Hi patzefran,

    We have discussed waterstay material earlier.

    To compare I put the Dyneema I use, side by side with Vectran.

    vectran.PNG

    BUT! The question now was whether I should dump the waterstays all together with the fatter main beam?
     
    Last edited: Oct 13, 2019
  6. patzefran
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    patzefran patzefran

    To compare I have used first so called high performance Dyneema (even heat treated) which was stretching at each sailing, then I switched to vectran which since worked satisfactory ! Dyneema is never used for rigging by professional.
    On the Dolphin striker of my Paper Tiger I have used 5 strands of 2 mm vectran looped thru Wichard articulated cadena bolted each side under the main beam and passing under the dolphin Striker (a 12 mm carbon rod). After two years of sailing, the mounting is as tight as new.
     
  7. revintage
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    revintage Senior Member

    Hey patzefran, your answer is still a parentheses even if I appreciate your input! I will use 3x4mm Liros Static-Pro "IF" I use waterstays. We also discussed masts at some point and will now use a cut down Goodall F18 mast without spreaders together with my cut down A-cat mains. Just curious, do you live in France?

    Did some more calculations and the waterstays will remain in place.
     
    Last edited: Oct 14, 2019
  8. patzefran
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    patzefran patzefran

    I think it is anyway a good compromise to use waterstays. Yes I live in France near Bordeaux !
    I also use a Cut down A cat main on a Shortened (8 m) A cat carbon mast on my Strike 15
     

  9. revintage
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    revintage Senior Member

    Great to have the bay of Biscay as sailing area!
     
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