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  1. neuronz

    Spar stiffening

    I second using sleeves. They are easy to apply also in multiple layers. Once tensioned and tied off they will stay in place to put on another one.
  2. neuronz

    Magic 25 Mast Ram

    We are using a small screw jack with a fine thread to lock down our keel with a wedge. Works very well and I can imagine one could use a similar system under the mast. Big advantage of hydraulics is IMO that you can easily add a meter to read pressure which makes it easier to record and...
  3. neuronz

    Spar stiffening

    If you decide to use carbon make sure to put a layer of insulation (i.e. light glass weave) between the two. Otherwise the aluminium will be gone in no time in a salt water environment.
  4. neuronz


    True. The picture actually shows why an elliptical planform is not optimal. The vortex at the tip has moved up along the trailing edge, reducing the effective span. This is why modern rudders have a square edge at the wing tip.
  5. neuronz

    Using an obstruction for port end of starting line

    We used to have our Wednesday night starting line between two channel markers and synched the start perfectly with the exit of a big ferry. Made the starts a bit more exciting.
  6. neuronz

    New Carkeek 45 splashed

    It also saves weight. There is less surface area in the topsides, deck and bulkheads. Plus the chinea acts as a stiffener and divides the panels which requires less support structure.
  7. neuronz

    Sailing to leeward of a windfarm?

    There has been some research done on this concerning the wind farms in the German north sea. Bottom line was that there is a reduction in wind speed behind wind farms. Depending on the atmospheric conditions this was measurable up to 50km behind the wind farm. Furthermore, researchers found that...
  8. neuronz

    what's the lightest portable marine head?

    Currently considering this Boxio
  9. neuronz

    that sinking feeling

    They told him submarines do not experience wave making resistance...
  10. neuronz

    Lann Ael 3 - Manuard / Nivelt IRC35

    Looks like someone forgot to bolt on the bulb. I know it's an IRC thing but there isn't even a taper, just a plain swept wing.
  11. neuronz

    How do you measure ISP for PHRF?

    You are welcome.
  12. neuronz

    Twisted Rod Rigging - now what?

    As long as you have only deformed it elastically it is fine (think torsional spring), plastic deformation will require replacement. The length of the twisted section will be important in determining whether you have one mode of deformation or the other. Basically there will be a limit of twists...
  13. neuronz

    TS5 capsize

    In your formula you are assuming a force coefficient of 1.0 which can easily be exceeded by sails. Since it depends on the wind angle which can change quickly on a multihull, a conservative approach would be to consider the worst case and use the maximum transverse force coefficient...
  14. neuronz

    Mumm 30 bowsprit mod

    There is a big difference in loads between masthead spinnakers and masthead C0s.
  15. neuronz


    Hi Julian, I guess it depends on the VPP. A 'normal' VPP based on regression formulas will not give a very precise answer and mostly show trends. However, you can also use a VPP to postprocess your empirical and measurement and CFD data and then things really start to get interesting. It...
  16. neuronz


    I looked into rotating keels in the past which is basically the same thing, taken to the extreme for the case of very wide hulls. You have a very small yaw angle already, so it might be borderline, but what I found was that the real benefits were in the aerodynamics. As you said your sheeting...
  17. neuronz


    Lift curve slope rule of thumb is about 0.1 per degree of angle of attack if I recall correctly. Going asymmetric mostly shifts your angle of zero lift so creates an offset. The only way to create a real gain (read reduction in area) here is if the asymmetric section has a higher permissable...
  18. neuronz

    Who know more about the Aeolos P30?

    The sailaway price comparison is missing ;)
  19. neuronz

    Mumm 30 bowsprit mod

    From a stability point of view a fractional sail might be the better choice anyway.
  20. neuronz


    Interesting, I would have expected the radius to suck down the tip vortex and reduce effective span. This is why rudders once were elliptical, but now have a sharp edge at the wing tip.

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