Dave_S

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About Dave_S

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    Queensland Australia

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  1. Thanks all, I'm sorted. I can run without life lines or jack lines provided everyone wears appropriate life jackets. Apparently there is a clarification/change coming soon.
  2. I was only given the audit form to go by. I'll do a search for the full set of rules. I was looking at the form where it said "if fitted" and assumed I didn't need them. I'm not going to fit stanchions so hopefully there is a way around it. We have to go out on deck to hoist and reef the main. I'm talking about a cat and the lines that you clip onto when going forward.
  3. I have no outside stanchions on my boat and don't want them. I would like to run life-lines from the cabin to run around both sides of the cabin then to the mast with a single line forward to the prodder. This is for social racing at the moment but I'd like to do it properly in case the bug bites and leads to more competitive stuff. Do you just run the forward line lying on the deck, can I run the aft lines up high (about chest height, against the cabin) The Cat 5 Audit talks about uncoated SS wire but doesn't say it has to be SS but it seems to be implied. Is there an approved alternative, I'd rather run a synthetic if I'm allowed.
  4. I'm thinking about entry level racing like WAGS (social racing), maybe more later but just simple for now. I've been doing WAGS on another guys boat for a year plus and now want to go out in my boat. It's a Schionning Waterline 1480. Nice older boat but not set up for racing. Performance wise I'll work on it as we go but my question is more about safety gear, both minimum requirements and good judgement. Is there a go to rule book or manual that isn't overly complex, written in layman's terms you would recommend?
  5. Dave_S

    Sorry repost please delete

    I've had more responses to this deleted post than the actual post, I got none on the other one, I'm such a sad case I had to answer my own thread.
  6. Dave_S

    Double luff mainsail for cruisers

    I thought you guys would be all over this. http://gre69.wixsite.com/advancedwingsystems https://m.facebook.com/story.php?story_fbid=1533335280082866&id=273328252750248 A 3D soft wing instead of a 2D sail. Has to be a good thing. More power, more speed, better pointing.
  7. https://www.sail-world.com/news/218372/Back-for-more-Much-more…?fbclid=IwAR1l-O9C-7_oj6OiTKqNYbYna5QUlIH-k19b4_RYBMTeLJa3Z5BvcaD8sZI
  8. I've been reading lots of sales pitches on sail material and am more confused the more I read. I have a Schionning Waterline 1480, whenever I sail it I try to get the most out of it and make the best VMG but it is a cruise boat and when finished we will sail off and probably do 4,000nm/year, with the exception of night passages I will always be trimming for speed. I might race it occasionally. I want the closest to "best performing sails" as I can but would like to get 5 or so years good life, how much do I need to compromise ? There seems to be much better materials now that maybe can do both ? Can they ? Sail shape.... Another compromise.... I assume it is a contradiction to have a sail shape that performs well in light air and also performs well close hauled ?
  9. I chose 8* because it is just above the stall figure for the wing profile if it were fixed, and why I picked +/- 10* travel into the wing. They are just figures plucked out of nowhere at the moment. In saying that it often pulls one or the other rudder out of the water. I get that it would be better to have maximum effort at maximum speed but the reality is my boat won't handle 2.5t smashing up and down on the rudder, I've picked 500kgs as a safe load, it maybe more or less. I'd be interested to hear opinion of the effect of these numbers on the boat? Maybe I don't need all of that? I have looked at two options Option 1. Have a fixed wing with 500kgs +/- lift on the rudder at max speed/angle and 200kg when close hauled Or Option 2. A self regulating wing that gives me 300 when close hauled and a max of 500kgs at a lower speed than max. It's not a complex design, I was happy with it's simplicity. I have assumed option 2 to be the best, but do you think option 1 is better ? It would have less drag.
  10. Another great post. I take your point about the research and cheap, quick test. I'll do that, thanks. The model I drew doesn't release the pressure. It will continue to increase resistance but at a reduced rate. Where a fixed wing increases at ^2 of speed at all speeds, this will allow it to increase at ^2 of speed, but only up to 8 knots/6°, there after it will continue to increase but at a reduced rate as the wing is allowed to rotate against the spring up to a maximum of 500kgs. So at 20knots and 8° pitch I will only have 500kgs on the rudders. It allows me to have a significant amount of pitch control at low speeds but without tearing my sugar scoops off at 20kn.
  11. 8 tons of lift, that's what worries me, while I expect to hit 20kn I don't want the lift to increase ^2 with it because the boats not made to take big loads but I want strong control at lower speeds. Without calculating it yet I guess my boat might be able to handle 4-500kgs per side on the rudders. My cunning plan #763 is to fit a pressure relief into the foils so I can hit 300kgs at 8 knots and thereafter bleed off the angle of attack up to X degrees at a max of 500kgs (10* shown in the image) up and down. I don't see why this wouldn't work providing the design doesn't run out of travel or jamb. I would appreciate comments from more cunning people than me on the principal. It's just a concept drawing of the spring action, don't get hung up on the details, proper design is a week+ work for me, and only after the principal and calculations are made.
  12. Thanks bushsailor, I am concearned about the maths of the forces increasing ^2. I might be beating upwind at 8kn in to the swell when I need it, or on a reach at 18kn. Has anyone come up with a limiting system i.e. a sprung loaded foil that holds against 4500N then can reduce AOA against the spring over X° to 5500N.
  13. I'm happy to do small projects but that's a major. I'm not sure of the benifit for me. I did think of a swinging curved foil in front of the dagger boards, like the AC monohulls, but without the righting force. I'll never do it but it would be the simplest retrofit.
  14. Thinking about a wing shape. I assume they are talking about the side profile when they talk about asymmetrical and symmetrical. I am leaning towards asymmetrical that generates neutral lift at no angle of attack and increases rapidly as angle of attack increases for the smallest leading edge profile. But I don't know enough to know if the front profile area reduction is equal to, less than or greater than the extra drag created from having a more aggressive wing profile.