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    • UnderDawg

      A Few Simple Rules   05/22/2017

      Sailing Anarchy is a very lightly moderated site. This is by design, to afford a more free atmosphere for discussion. There are plenty of sailing forums you can go to where swearing isn't allowed, confrontation is squelched and, and you can have a moderator finger-wag at you for your attitude. SA tries to avoid that and allow for more adult behavior without moderators editing your posts and whacking knuckles with rulers. We don't have a long list of published "thou shalt nots" either, and this is by design. Too many absolute rules paints us into too many corners. So check the Terms of Service - there IS language there about certain types of behavior that is not permitted. We interpret that lightly and permit a lot of latitude, but we DO reserve the right to take action when something is too extreme to tolerate (too racist, graphic, violent, misogynistic, etc.). Yes, that is subjective, but it allows us discretion. Avoiding a laundry list of rules allows for freedom; don't abuse it. However there ARE a few basic rules that will earn you a suspension, and apparently a brief refresher is in order. 1) Allegations of pedophilia - there is no tolerance for this. So if you make allegations, jokes, innuendo or suggestions about child molestation, child pornography, abuse or inappropriate behavior with minors etc. about someone on this board you will get a time out. This is pretty much automatic; this behavior can have real world effect and is not acceptable. Obviously the subject is not banned when discussion of it is apropos, e.g. talking about an item in the news for instance. But allegations or references directed at or about another poster is verboten. 2) Outing people - providing real world identifiable information about users on the forums who prefer to remain anonymous. Yes, some of us post with our real names - not a problem to use them. However many do NOT, and if you find out someone's name keep it to yourself, first or last. This also goes for other identifying information too - employer information etc. You don't need too many pieces of data to figure out who someone really is these days. Depending on severity you might get anything from a scolding to a suspension - so don't do it. I know it can be confusing sometimes for newcomers, as SA has been around almost twenty years and there are some people that throw their real names around and their current Display Name may not match the name they have out in the public. But if in doubt, you don't want to accidentally out some one so use caution, even if it's a personal friend of yours in real life. 3) Posting While Suspended - If you've earned a timeout (these are fairly rare and hard to get), please observe the suspension. If you create a new account (a "Sock Puppet") and return to the forums to post with it before your suspension is up you WILL get more time added to your original suspension and lose your Socks. This behavior may result a permanent ban, since it shows you have zero respect for the few rules we have and the moderating team that is tasked with supporting them. Check the Terms of Service you agreed to; they apply to the individual agreeing, not the account you created, so don't try to Sea Lawyer us if you get caught. Just don't do it. Those are the three that will almost certainly get you into some trouble. IF YOU SEE SOMEONE DO ONE OF THESE THINGS, please do the following: Refrain from quoting the offending text, it makes the thread cleanup a pain in the rear Press the Report button; it is by far the best way to notify Admins as we will get e-mails. Calling out for Admins in the middle of threads, sending us PM's, etc. - there is no guarantee we will get those in a timely fashion. There are multiple Moderators in multiple time zones around the world, and anyone one of us can handle the Report and all of us will be notified about it. But if you PM one Mod directly and he's off line, the problem will get dealt with much more slowly. Other behaviors that you might want to think twice before doing include: Intentionally disrupting threads and discussions repeatedly. Off topic/content free trolling in threads to disrupt dialog Stalking users around the forums with the intent to disrupt content and discussion Repeated posting of overly graphic or scatological porn content. There are plenty web sites for you to get your freak on, don't do it here. And a brief note to Newbies... No, we will not ban people or censor them for dropping F-bombs on you, using foul language, etc. so please don't report it when one of our members gives you a greeting you may find shocking. We do our best not to censor content here and playing swearword police is not in our job descriptions. Sailing Anarchy is more like a bar than a classroom, so handle it like you would meeting someone a little coarse - don't look for the teacher. Thanks.

jetboy

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  1. Thanks for the suggestions! I found a workable solution for now. I ended up making the outer parts clamp. They clamp down really well and I made the straps out of 1" x 1/8" stainless, so they're really strong. Once the outer tubes are released the system slides pretty well with just a little car wax to lubricate it. I do still want to move to a folding mechanism just for ease of assembly and coolness factor, but for now it works. I've timed it from parking to water in around 30 minutes. I'd like to have it at 15. Over 20 minutes of the time is for folding out and assembling the trampolines. Here's a picture of one of the clamps. I think the whole system is way overbuilt as a result of the aluminum tubes I have available off the shelf.
  2. A hang glider may position the COG below the center of lift. I don't know how one might accomplish that with a sailboat on foils. The distance between the foils is related to the static stability. Within the very narrow range of pitch that a typical foiling cat is statically stable, the feedback mechanisms struggle. The further they are apart the more stable the boat will be. And the greater the effect of the forces to remain in equilibrium.
  3. Many new generation fighter jets have the wing equivalent of a shoal keel. I suspect it is primarily a function of slipstream. The rear wings are effected by the slipstream of the front wings in air. Water at the speed of sailboats doesn't have the same properties as air. Surely you can still drive a forklift with 49% of the weight ahead of the front wheels. That's basically what we're doing with a typical foiling sailboat. It's just not very stable. I suspect it may be possible that stability will expand the use of full foiling beyond the tightrope balancing act that limits its use cruising boats. The additional weight of the foils is basically meaningless on a cruising cat. I'd guess the additional weight of structure is significant though. But I really don't know having not done any modeling. I suspect you should pick up an aero textbook. Fighter jets have advanced control systems, well beyond any sailboat, including AC level tech. They run negative static margin, i.e negative stability. Thus, they are inherently unstable, and rely entirely on the computer to fly. Their wing position has very very little to do with anything hydrofoil related. More to do with Mach effects and being able to efficiently maneuver at a high range of speeds, from 100 kts to Mach ~2. https://en.wikipedia.org/wiki/Area_rule; they can operate with very low tail volume coefficients, and relatively large, efficient wings (with many complex features such as flaps and leading edge slats to allow for high CLmax's and thus low speed flight, while relying on supercritical airfoils for high speed flight) because the computer is keeping the system happy with control surface inputs (of which there are many, many more than we have available on modern hydrofoiling sailboats). Sailboats generally don't have the advantage of modern closed loop fly by wire digital control systems. They must operate in statically stable configurations, ala your typical GA aircraft (alos note: very few of those running around with canard configurations), or only the worlds best sailors would have any chance of sailing them! I don't think airplanes offer much in terms of analogous design - especially for the part below the waterline. That was kinda the point. Having 2 pairs of wings that both provide lift is difficult because they are not independent. The rear set of wings will be significantly effected by the front. Anyway - the same issues do not apply to foils. Operation at a boundary between water and air offers a unique opportunity for dynamic lift with fixed foils. The problem I'm thinking about is the failure of basically every common foiling boat to offer stability and most importantly there are very few that can be sailed with low effort AND low risk of pitchpole. Moving the foils to the outer limits does require that all 4 provide vertical and horizontal lift. it should offer the benefit of eliminating the need for complex pitch control. Possibly even eliminating any active pitch control.
  4. Many new generation fighter jets have the wing equivalent of a shoal keel. I suspect it is primarily a function of slipstream. The rear wings are effected by the slipstream of the front wings in air. Water at the speed of sailboats doesn't have the same properties as air. Surely you can still drive a forklift with 49% of the weight ahead of the front wheels. That's basically what we're doing with a typical foiling sailboat. It's just not very stable. I suspect it may be possible that stability will expand the use of full foiling beyond the tightrope balancing act that limits its use cruising boats. The additional weight of the foils is basically meaningless on a cruising cat. I'd guess the additional weight of structure is significant though. But I really don't know having not done any modeling.
  5. So would you also want your front tires near the center of your car? I think the same reasoning applies equally to both situations. It seems that the ideal scenario would be 4 foils at each corner that all steer and provide both lateral and vertical lift. The benefit should be a dramatic improvement in stability. Mechanically it would be quite difficult to have 4 foils steering together efficiently, but it's not impossible.
  6. This may seem really simple - but why are foils typically centered in the same location as traditional centerboards. Instead of using essentially only the center foils for vertical lift and the rudders for tilt control, why not move the foils out to the outer limits? There's a reason we don't drive around unicycles. The stability of using foils at the corners and relying on the rudders or rear foils for the half of the vertical lift. I recognize that this wouldn't be ideal for non-foiling situations. Help me understand why it's not done this way for pure foiling type boats.
  7. I hate to be the bearer or bad news, but very few buyers really care much about going as fast as possible. I don't drive a Z07 to work. I don't even own a sports car anymore. What's fun for 20 minutes isn't always fun for 5 hours. That's what separates what I consider the beach toys (kite boards, windsurfers, and most beach cats) from the small trimarans. If the longest sail you'll normally go out for is an hour or less, sure - foil away. If you want to go sail for a longer day, bring lunch, have a few friends along, anchor and swim, etc. You don't want to use a beach toy. Sure there's some overlap in size, but I suspect there's not a lot of overlap in use. A foiling 18' trimaran would be a beach toy category boat. It surely would be fun - for 20 minutes. I don't think it would be fun for 5 hours.
  8. If the tri can fly the main hull, the amas of the equivalent cat needn't be any heavier than the tri's amas, so the cat can match the inertial characteristics of the tri by adding central ballast, or go faster without it and have lighter amas too. The further the crew can get from the foils, the more RM you have, so you definitely want the foils under the ama. Where a central foil might provide a gain though is where it is deeper than the ama foils and can generate downforce - that can handle a bigger rig while reducing the danger of the downforce-generating foil from popping out of the water due to wave troughs, but this could be done on a cat just as well as a tri and with less weight overall (and you'd only deploy it in strong winds when you need the downforce, and perhaps in light winds where you want more lift to take off in light winds). It depends on how much structure of the floats you're relying on. But in general I agree. The reality is that the scenario of flying the center hull is extremely rare in any trimaran. I've never seen it done for more than brief periods. Additionally with a trimaran the center hull provides additional buoyancy when the ama submerges. A cat has no such ability. For example a trimaran could very well use two amas that are maybe only 10% greater buoyancy than the total boat, still fly the center hull, and be safe and stable while flying on an ama that's 90+% submerged. That's not a realistic option for a cat. A cat generally must have around 3 times the boat's weight of buoyancy in each float. In most cases I think the weight at the extremes is preferable. It will slow most motions and resists gusts better. It will make tacking more difficult as well as righting more difficult. The problem with offset foils from the center of effort is that they are only optimally efficient on one point of sail. On all others they are not optimally located and the sail balance changes leading to sub-optimal sail trim to compensate for the unbalanced center of effort of the sails to the foil. With a cat that's 8' wide - no problem. With a 16' beam it starts to become more and more of an issue. There's a significant offset between a close reach and a broad reach. My trimaran has Nacra hulls and I left the dagger slots and rudder hardware. So I can mix and match and my experience is that a center hull foil pair is better in every scenario except flying the center hull, which practically never happens.
  9. While the net RM may be the same with a cat or tri of similar weight, the motion will not. Moving the weight to the outer edges of the boat will result in greater inertial resistance to motion. Whether that's good or bad depends on what you're attempting to accomplish. Also, having the foils in the center hull will have some inherent benefits as compared to having them separated by some distance from the center of effort of the sails. I don't think it's significant, but there is some small benefit there.
  10. Peter, I think it depends on the size of the amas more than anything else. I know for a fact that an 18' tri with low buoyancy amas can be built very close to the cost of an F 18 cat-no doubt about it. I would argue that an 18' tri of similar materials and craftsmanship would likely cost more than a cat. The cost difference being in the complexity of the center hull, and the folding mechanism. Not the floats. The materials are a small portion of the overall cost. If you use a centerboard/dagger and rudder on the center hull, you've eliminated a rudder assembly and a daggerboard along with all of the manufacturing that goes into putting them in the hulls. So you have some savings there. The main hull is a LOT more complex though on most trimarans. My center hull has IIRC 5 bulkheads, a cabin, seats with underseat storage, a complex internal structure to support the higher loading of the beams, and a lot more volume than any beach cat hull would have. I don't think the savings on hardware and manufacturing of the amas will makeup for the complexity of center hull if it's anything like mine with a cuddy cabin and more complex internal structure. I also have things like a self draining anchor locker. Most beach cats are just two floats with minimal manufacturing complexity. That said - I'm confident a trimaran could be manufactured and sold at a much lower price than most we see. I think the Astus 16.5 is a perfect example and I believe that boat could be scaled up in length to 18-19' with limited additional expense.
  11. From my experience, from someone who's had both - I'll take a trimaran every time as personal boat. There are a lot of reasons, but primarily the versatility. Trimarans of similar size will go fast and go slow well. I really couldn't care less if I was faster than a beach cat. Typically I can outrun them - especially to wind, but a fast cat on a beam reach in light wind often will leave me behind. What I like about a trimaran is the comfort of a regular cockpit when I want it, dry sailing when I want to, ability to take 6 people sailing with a cooler of beer. And still have the ability to get wet, go fast, hit high teens speed, and still park the boat in my garage. There are no beach cats that have the range of use that an 18-20' trimaran offers. I suspect the speed has a lot to do with the beam and the feeling of security it gives. My 18' tri has a 15' beam. It rarely ever feels unsafe or unstable. As it heels when I push it hard it's a slow controlled motion. I think the result is the ability to push harder because it's easy to control as you approach the limit.
  12. You can admit it was effective even if you don't like the purpose. Everyone by now should recognize this. There were many reasons it failed, the primary one being that it was a government built wall to keep the citizens IN and eventually the citizens overcame the government to get OUT. Our wall will be the reverse where the keeper of the wall will have the incentive to maintain it. And with luck it will be completely useless in 28 years. By then we might have a complete immigration reform and almost certainly will have electronic tracking of every single individual sufficient to eliminate the need for the wall. As of today we have neither. In a perfect world Mexico's own economy will boom to the level that its citizens have great opportunity at home and don't want to come to the USA for work. The European walls are quite long as well.They are not a substitute for boarder security. They are a physical barrier that allows fewer guards to enforce larger areas. Of course we *could* enforce the entire boarder with shoulder to shoulder security. Just like I could enforce my property boundary with 24 hour security. Or plchacker could keep his horses in with round the clock supervision. But smart people use tools to reduce labor. A fence is nothing more. It's a tool to reduce labor. And it works Shit, we've moved from voter ID to "Complete Electronic Tracking" So - are we going to all have the little "find your pet" microchips embedded in our person? Fuck you guys like big gov't. I'm not passing a judgment on it. Just saying that IMO it's a near 100% certainty that in 30 years every single person will be trackable in real time.
  13. You can admit it was effective even if you don't like the purpose. Everyone by now should recognize this. There were many reasons it failed, the primary one being that it was a government built wall to keep the citizens IN and eventually the citizens overcame the government to get OUT. Our wall will be the reverse where the keeper of the wall will have the incentive to maintain it. And with luck it will be completely useless in 28 years. By then we might have a complete immigration reform and almost certainly will have electronic tracking of every single individual sufficient to eliminate the need for the wall. As of today we have neither. In a perfect world Mexico's own economy will boom to the level that its citizens have great opportunity at home and don't want to come to the USA for work. The European walls are quite long as well.They are not a substitute for boarder security. They are a physical barrier that allows fewer guards to enforce larger areas. Of course we *could* enforce the entire boarder with shoulder to shoulder security. Just like I could enforce my property boundary with 24 hour security. Or plchacker could keep his horses in with round the clock supervision. But smart people use tools to reduce labor. A fence is nothing more. It's a tool to reduce labor. And it works
  14. Almost all walls for immigration purposes work. The Berlin wall worked exceptionally well. The wall between Hungary and Serbia dropped the rate of illegal immigration from about 10,000 per day to around 10 per day. Turkey, Greece, Bulgaria, and Macedonia all have similar walls that have been similarly effective. There are 65 current boarder walls or fences. You can find any of them you wish. Nearly the entire eastern and southern land boarders of Europe have migrant fences. If Belarus and Latvia connected the boarder fences of Ukraine and Estonia there would be a continuous border fence on the entire eastern front. Similarly if Ukraine built a wall on its border with Moldavia and Romania the entire southern border would be fenced - almost entirely DOUBLE fenced becasue there are border fences south across Macedonia and Bulgaria. These are all new since the Berlin wall... and they're not building them for fun...
  15. Where do you get that stat? It sounds nonsensical. What's the point of having a wall to stop undocumented workers when illegal hirers like Drumpf keep up the demand for undocumented workers and keep hiring illegally? And more, since we obviously don't enforce illegal hiring laws, why not? The benefit of those people to our economy and demographics? A fence with the same law just seems silly to me. As far as "keeping us safe", I've noticed that nobody in this thread has tried to support that one. In 1952 the inner German border was closed and Berlin had mixed control and resulted in a loophole in the immigration rules between east (soviet) and west Germany. Migration was nearly 100% westward out of east germany. The wall was built to keep people IN not OUT. It was effectively a prison wall. During the time it was maintained only about 5,000 people successfully escaped - and roughly 1/3 of those were guards. Prior to the wall being constructed about 500,000 people per DAY crossed the border. Mostly east germans going to work in the west and returning. The net immigration from east to west became a problem for the east. Between 1946 and 1962 roughly 2,500,000 east germans immigrated permanently to the west. In 1961 the rate of migration was about 150,000 per month to the west. Between August of 61 and 1989 the wall was extremely effective. Had it only been 99.99% effective as compared to the immigration rate in July of 1961, the expected immigration over the period would be about 5,040. So while not exactly precise, 99.99% effective is pretty damn close. The Berlin wall was a very bad thing for a lot of reasons, but it was very effective. Anyone who thinks otherwise is simply ignorant. If it wasn't effective - no one would have cared about it. It is hard to stop illegal hiring entirely, but I agree that we need major reforms in our employment law both for workers and employers. In today's world it's pretty damned easy to create a system that works and is reliable to verify citizenship... if you want to. Deporting is like bailing water. It makes no sense to start deporting or even changing the laws without fixing the hole in the boat first. IMO the gaping hole is the border security. The second step is setting up a streamlined work visa process with employer tracking and employer requirements. Third down the line is deporting illegals or working on a permanent status. But securing the border is the first step in any rational process to address the problem. And fences work. And no - you can't have open borders if you also want to maintain our society. It will be the fall of the EU. The tragedy of the commons is as relevant today as it always has been. And it's the reason we generally know that posters are just lying when the say that they have open door policies at their homes/property. It never works. Never has. Never will.