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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.

12 metre

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  1. Makes sense from a practical point.
  2. The photo illustrates a couple of important wing keel features that the designers of most production boats either choose to ignore or were unaware of from a performance perspective: 1.The winglets should be dihedral (drooping down) like in the above or as in A2 below. If they "droop down" 30 degrees, then at 30 degrees of heel, then the wiglet span is only 30 degrees from vertical - the same as the keel. So the winglet becomes just as efficient at translating lift to side force as the keel. If the winglet is perpendicular (like most) then at 30 degrees of heel, the span is 60 degrees from vertical resulting in relatively little side force. 2. The nose of the winglet should be just aft of the main foils pressure roof (typically about the point of maximum thickness). If the main foil is a keel, that will usually be 30-40% aft (like in A2). if the main foil is a properly designed bulb (where maintaining laminar is the primary consideration), then it would likely be as much as 60% aft or more (like in the Howlett winglet above).
  3. i have a couple of basic tenets for working on boats: 1. Avoid anything with large teeth 2. Avoid anything capable of generating large dE/dt
  4. A small amount of C4 would probably loosen things up pretty well too - but I am not going there either
  5. I have seen that before but thought is was some type of martial arts or battle weapon.
  6. A pictured is worth a thousand words in this case. Below is the image I attached way back in Post # 58 which I think explains this. You can see how the leeward side of a keel has a downwards flow component (which grows stronger towards the tip) resulting in an AOA to produce a downward (and windward force) on a dihedral winglet. On the windward side, the opposite occurs.
  7. I often used a grinder with cutoff wheel for fiberglass - goes through fit like a hot knife through butter. But a bit too efficient for my liking - especially when cutting near the inside skin. One slip could do a lot of damage. But my main concern about using a grinder for cutting out as bulkhead is that I'm also cutting through plywood and I was under the impression there is no proper wood cutting wheel for a grinder. A guy I know said he's done it, but with a lot of smoke. Also use an Ultra-saw quite a bit for cutting straight lines in fiberglass and plywood. Basically it is a grinder with a depth guide. The drawback in this application is that it is only good for straight lines and impossible to get anywhere near a flush cut in this case.
  8. I would enjoy seeing that. Might give me a few ideas as I`m planning on doing something similar as you know.
  9. With that sort of configuration, you're almost evolving a bilge keeler into a ballasted catamaran. One problem with a bilge keeler is that as it heels, interference drag goes up at the keel root. When it finally does start coming out of the water, it creates it's own separate wave train, which would get really ugly as the bulb starts coming out.
  10. Yes, I addressed that I think on my previous post. To have an 11,340 lb bilge keel would mean a likely overall displacement in the neighbourhood of 50,000 lb. Using a Westerly Centaur, total ballast is some 2800 lb or 1400lb/keel. Assuming the entire keel is lead, dividing by the lead SG of 11.34 (as you provided) equates to 123 lb of buoyancy. Which is greater than zero, but represents less than 2% of overall displacement.
  11. Technically you are correct. When the weather bilge keel comes out of the water, it is no longer displacing water so the CB shifts to leeward - analogous to a catamaran hull. I haven't tried running any numbers since bilge keel design is not on my radar - but I suspect it would not be a large amount since a bilge keel when immersed does not displace very much - compared go a catamaran hull.
  12. Yes, they are different in that you can quantify RM but you can't for "stability". One is an objective measure while the other is subjective. Not a crackpot, because it is a fairly common misconception. The only way to increase RM is to either shift the CG outboard or the CB inboard (see Semi-Salt's post below). You are over-complicating the matter. I don't have to run the numbers because fixed bilge keels will not cause the vessels CG to shift when heeled and that is the only thing that matters. A similar misconception applies to water ballast. I have seen it argued that water ballast only creates RM when the water ballast is out of the water (neutral buoyancy argument), but this is completely wrong because again, the only thing that counts is the overall CG, and that doesn't change when the water ballast is out of the water.
  13. The forward one will come out later after I`ve built the new one in the new location about 4 ft aft. The forward one looks pretty easy to take out since it was bolted to the liner and that is gone now. The ones I`m cutting out now are the partials one attached to the end of the settees. I agree its pretty easy to chisel out the tabbing in places like under the deck at the deck to cabin joint - but I can`t find a place to start in the bilge or topside areas. The process would probably be a lot easier if the plywood was rotten, but it`s only a bit punky along the bottom couple of inches.
  14. That's a fairly common misconception. Yes, the CG of the windward keel moves further ``├▓utboard``, but this is exactly offset by the leeward one moving less so. But that`s not the proper way to look at it really. While the CG of the various components factors into the stability analysis, in the end the only thing that counts is the overall CG of the vessel, and that won`t change when heeled whether you have one keel or two (unless you can cant the windward one) Also, whether heeled or not is irrelevant too. The typical methods of increasing RM (Canting keel, rail meat, water ballast) will heel the boat to weather when deployed at 0 degrees. You will note that a bilge keeler does not do this
  15. Even the Harbor Freight ones are better than those. Those are the ones I mentioned that wore out in a couple of minutes. When I said "invest in a decent plunge cut blade", I didn't necessarily mean pricey, I meant bi-metal like the second Harbor Freight ones you listed. I think there are titanium tipped ones (or something like that) available at CT for not a whole bunch more money.