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neuronz

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About neuronz

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  1. Well that is probably because crew is the second item on the cost sheet and systems trimmed by the crew require more and more qualified crew and will likely still perform worse than computer controlled systems.
  2. Some boats simply put velcro tapes next to the winches and on the winch handles.
  3. To make this call you would have to investigate the expected angles of attack in more depth. The 10% section with chordwise extensions will have more area and lower aspect ratio and thus more resistance than the 12% section. However, the reduced area with the 12% option will be offset by a higher angle of attack (more leeway) which can (should if the keel was properly designed initially) decrease the lift to drag ratio of the section. Furthermore, the resistance of the hull will also increase with more leeway. In my opinion the 10% option with constant area is the safe option. Generally 1
  4. A thicker section will not give you more lift as such but tolerate higher angles of attack without stalling through which the loss in area will be compensated. Going with the 12% section would be the easy way. Ideally you would keep the area constant by adding some fairings at the front and back of the keel to keep the lift in the same longitudinal location.
  5. There are elastic tapes to seal the mast at the partners. We have had good experience using it. Some boats also have a neoprene cover, but that has to be put on the mast before stepping. Also if you have issues with water entering through the bowsprit housing, you might want to close the front of the bowsprit with a ball or whatever fits. It is by far the biggest opening of the housing.
  6. Assuming a foil designed to produce both sideforce and vertical lift, it needs to have two parts. One part approximately vertical for the sideforce and the other one somewhat horizontal. For simplicity let's assume it is an L-shape. With both parts creating lift they both have a low pressure area associated with them. The vertical part on the windward side and the horizontal part on the upper side towards the water surface. For an inward facing foil the horizontal part extends from the vertical part to windward. This means that the two low pressure areas meet at the intersection between b
  7. On the topic of foils, inside facing foils will cavitate earlier than outside facing foils because of the superposition of low pressure areas from the vertical and horizontal parts. This can be mitigated to some degree by increasing the transition radius between the horizontal and vertical parts.
  8. I have seen many boats having their leeches too tight which then drop the traveller to reduce heeling. Inefficient. I think some of this due to sailors moving up from dinghy classes where you can use vang and boom to induce mast bend and flatten the sail. This usually does not work on yachts. Generally stalling the sail is not fast as it creates less drive force and more heel. You might have to play with the upper part of the sail. With a fractional rig this area will not benefit from the inflow from the jib and thus stalls more easily. In certain conditions it thus might make sense to st
  9. Do you have the means and/or skill to finish it? This can be a great deal or 2k$ wasted on garbage. One question I would ask is why the boat has been sitting for a year, i.e. is there something wrong with it? In general I would not worry too much about being stored outside since this is what boats are made for. However, I would be concerned about a few things: 1. Has the boat been painted/covered, especially the area facing upwards. Resins do not like UV. 2. Does the boat have any holes where moisture can get into the laminate? Depending on the materials (resin & core) used
  10. I do not have any issue with anyone updating their boat. However, we are not talking a little TLC here. My point is that it probably would not have placed so far forward if it would not have gotten a new keel and bulb etc. since the original argument was that the boat seems to have a long competitive life span.
  11. Only that this one is far from stock with regular updates from Farr etc.
  12. Pretension in the range of 20% break load is nothing unusual. As a measure of thumb the leeward shrouds should only become slack at your maximum sailing heel angle. In general the hull should not deform permanently. If you give it some rest during the offseason it will go back to its original shape. If you keep the tension for several years or if the boat is weakened otherwise it is a different story.
  13. I am not sure a windsurfer is a good analogy. The cant the rig to windward to be able to get their bodyweight outwards which is their primary source of righting moment and probably sacrifice some aerodynamic efficiency for that. However, what you can learn from a windsurfer is that canting and tilting also have a steering effect and need to be balanced, i.e. if they tilt their rig to windward the center of effort also moves to windward which they offset by tilting the sail aft to go in a straight line. Hence if you cant your rig to windward your boat will develop more lee helm unless you
  14. The rig is most efficient when vertical. Beyond that I would expect any benefits to come from additional righting moment as the vertical force will be tiny in relation to the weight of the boat. Also the efficiency decreases again past vertical.
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