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Thread: Cool stuff

  1. #136
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    Ok, stretch it a bit, smooth it out a touch and give it a pointy end. Add some wings, a centre case and foils. Call it the "Ultimate Foiler". Dead sure this could work.

    ImageUploadedByTapatalk1375876543.600736.jpg


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  3. #137
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    How do you spell pun???? Dead funny that is. Put a smile on my face and I needed one badly.

  4. #138
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  5. #139
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    Having stuck a few foils on things in the last few years, I can tell you stuff will break and the loads on the case, rudder attachments and foils themselves are significant. As you'd exspect the key is two fold, weight and enough performance potential to get foil borne. It would be interesting to see a GIS flying, so who's got nothing better to do this winter?

  6. #140
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  7. #141
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    Quote Originally Posted by woodeneye View Post
    Ok, stretch it a bit, smooth it out a touch and give it a pointy end. Add some wings, a centre case and foils. Call it the "Ultimate Foiler". Dead sure this could work.

    ImageUploadedByTapatalk1375876543.600736.jpg


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    Which end would be the bow, Bruce?


    I'm curious as to the lessons coming out of the current crop of AC72 cats, and whether that will trickle down to other boats. The Moths and the foiling set-up for a Laser both have active control of the angle of attack of the horizontal foils through that wand and a linkage to achieve altitude control. That sort of set-up was banned for the AC cats with the aim of ruling out foiling, but the Kiwis figured out how to achieve stable foiling without active pitch control. (What is special about what has been achieved here, how did they make this work when the rule makers thought they had ruled it out?) I'm wondering if/how that will feed down into smaller boats, cats or otherwise.

    I'm visualising a boat the width of a Goat, but maybe shorter, made as light as possible, the same flat bottom and slanting in sides, no centreboard, but a curved leeboard hung off each side. It would need a rig with a greater lift to drag ratio to the Goat, maybe that bigger mylar rig Bruce showed that will fit a laser?

    Foils for the Storer 12!?

    Ian

  8. #142
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    I think the Moths proved you didn't actually need flaps or an adjustable foil on the rudder to actually foil. They just find it more convenient to get a quicker launch if that control is there, and it can also help prevent a crash if the lifting foil cavitates. Likely the big AC72s just ran with that idea, although, as Tom mentioned in his video I posted, they do actually have a variable pitch on the rudder, just that it isn't adjustable while sailing and they have to stop to make any changes to the angle.

    As for trickling down, that's usually what happens eventually. Just like the features we see on our cars these days first appeared on the race track. However, it's also interesting to actually see the reverse is also happening too, ie. a trickle up on certain technologies such as wings and foils.

    The best way to test ideas is to actually build the thing Ian! The Moths seem to have become stuck as a development class, with many of the modern breed of foiler sailors just coughing up the dosh to buy their shiny new carbon black Mach2 and going sailing. In the past, Moth sailors were also the innovators, and in the off season they would all be working feverishly on their ideas. Some of these weird ideas worked, some didn't. I'm not saying there aren't innovators among the fleet any more. They are there, but in far fewer numbers than there were in the halcyon days of Mothing and they seem to be working on small incremental improvements, for example lifting foil profiles, separately adjustable foils, canting rigs etc. What happened to the Moth wing we saw in 2011 at the Worlds in Belmont? There was heaps of development left to do with that, but it disappeared and probably ended up being stuck onto an Optimist. Just what will be the next big thing in Moths? In another 5 years, will we just see coloured Mach 2s, or will there be something new that's really meaningful that will blow us away? A kite sail perhaps? Just don't hold your breath while we wait!

    Were you thinking of the Byte CII rig?

    Edit: A kite sail on a Moth won't actually be possible unless the rules are changed as the sail has to be attached to the mast between the coloured bands. That may actually have been the rule that squashed the wing.

    Edit2: Actually, wing sails are allowed, specifically. See attached Moth Rules.
    2013 rules MTH2013CR220313-1.pdf

  9. #143
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    Hi Bruce,

    With hydrofoils there are two schools of development.

    The Moths had the early running, first trying a tricycle configuration. They were disturbed about that because it made the boats too easy to sail and was complex and bulky. Then Ian Ward (to prove the naysayers wrong) developed the bifoiler. Since then the bifoiler has developed into a very adjustable package. My expectation is that because of the different target speeds on the different points of sailing and the different amounts of forward force available that there would be substantial fine tuning of boat attitude (through the rudder flaps) and I'm sure that they will eventually make the linkage from the wand to the centreboard flaps more instantly adjustable while sailing for ride height - you want to fly high in smooth conditions but want the hydrofoils below the troughs of the waves when it is rough. This was ever the way of top level boats - more and more adjustabilty if it is allowed.

    Multis on the other hand have decided that the flapped arrangements are not good (at this stage anyway) - possibly an attempt to ban initially and also some of the problems of the tricycle configuration - making it too easy to sail. Can't have just anybody jumping into A-class cats - which was a stated fear of the moths when the boats were too stable. So far their experiments in smaller cats haven't been terribly successful without flaps - a much touted hydrofoil A-classer was much slower upwind and somewhat better but "still nothing special" downwind.

    But you never know what will happen with week by week sailing with competitive mindsets and smart people will get to. But so far ... no banana for the multis.

    So the effective point of flaps is an ability to change the effective camber of the foils, the effective angle of incidence of each and the relative angles of incidence of rudder and centreboard foils - you need rudder down to get the nose up for efficient lift off and then set neutral rudder to not override the main foil height mechanism so it sets the main foil for low drag. Because the AC boats are not allowed to use flaps - or if they do they are not allowed to move them without remeasuring the New Zealanders alter the angle of the main foils with powerful hydraulic jacks - which is a rule "cheat" (or a follow on from the rules) using a sledgehammer to crack a walnut compared to flap control.

    I might be wrong on some of this, but I think the rudder flap will be moved to different settings for different points of sail and also for pre and post manouvre - such as tacking and gybing and conservative setting for starts and buoy roundings when there is pressure on from other boats - then set to lowest drag downwind when there is plenty of forward power etc.

    MIK

  10. #144
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    Yes, the Moths do use the rudder foil dynamically and obviously they need the control around the race course, but it's not essential for foiling (ie. the Laser system). There are systems for adjusting ride height via the lifting foil that are independent of the rudder foil. Also, walking through the boat parks, you see an even mix of wings with flaps and those that vary the pitch of the entire foil (eg. the new Laser foil design). Some are adjusting the port and starboard foils independently. The mind boggles thinking what these must be like to sail if you throw a canting foil and canting rig into the mix! It would be very hard to have your "head outside of the boat".

    The point I was trying to make was that there seems to be both a trickle up and a trickle down, technology wise, and it's no longer a top down one way street. Apart from a fancy coffee machine on board ETNZ, I'm a bit hard pressed to think of any brand new technology on these AC boats that we haven't seen before on other boats. Same with the Moths, the centre-foiler has been around for 14 years and most of the development has been around foil control and profiles. Split foils are also appearing, but do they count? I guess control systems should count for something, as we are all a bit obsessed with control of our boats! Canting rigs are showing up, but that's not really new, although the purpose of it on a Moth is different to its purpose on other dinghies.

    The AC72s are so huge, that the team which can control their beast the best around the course will win. Straight line speed without control doesn't cut the mustard, as we've seen. So, are the AC72's good for the advancement of sailing? They are certainly spectacular to watch, but will we see any new stuff come from them?

    Mmm, it IS a coffee machine on ETNZ isn't it?

  11. #145
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    Completely agree, Bruce.

    I don't see anything really new in the AC72s except for the scale.

    C-class have more radical hulls and the low freeboard shows they have made really significant gains in the hull dynamics for less tendency to nosedive.



    And looking at the wing - it is such a simple elegant structure compared to the AC72s.

    Moths can foiil in this much wind and less - even down to glassy calm if they can get up in the first place



    I do see some tech in the centrecase jacking ... I'm not sure but I think a foiling moth goes around a racecourse about equal with an A-class cat - which is something a foiling A-class can't do. I suspect it has too many foils for the job - my hunch is that two foils in the water is the minimum drag configuration to match a good conventional multi ... for the moment certainly ... and maybe for much longer.

    Ruminations
    MIK

  12. #146
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    I'm inclined to agree Mic, two foils will be the fast ticket and along with weight reduction, which is a continously on going engineering issue, control and foil innovations will be what's next.

    I've tried dagger foil jacking which has merit, but in all but small craft, prohibitively costly, if some level of reliability is desired. My last jack was a trailer worm screw and crank. A damn heavy thing but it worked. Okay, maybe I just felt bad about the weight when it was installed, compared to the blade/foil combination it was jacking. Anyone got some carbon worms and pinions cheap? I've debated casting some, but elected not to waste good material on a potentially flawed idea.

    I'm looking for attitude control innovations. Maybe some electronics and servos, possibly some lasers to check height and attitude and some auto controlled adjustment. I don't think GPS is accurate enough, but maybe in the future. Systems like this exist, but wow they're expensive. We should get to a point, much like the F-117 and B-2 flight controls, where the only way it works (flies), is to take humans out of the decision loop and let the processor (and control surface servos) do the dirty work, while the skipper offers "suggestions" to the processor as to course. I see this as the only practical way to fly larger craft with lubbers aboard.

  13. #147
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    Quote Originally Posted by woodeneye View Post
    Guys, put your orders in for Fathers's Day/Christmas/Birthdays. A salty gift for sure, the Swiss Army "Skipper" knife, complete with shackle key

    Attachment 218163
    No fid, what kind of knife is that?

  14. #148
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    Quote Originally Posted by woodeneye View Post
    At our local shopping centre today I saw a 3D printer in action for the first time. Engineering students were designing all sorts of cool stuff and then printing them out. I've seen them in videos, but never for real. They are simply amazing. It was similar to this one, which is just a baby compared to the big industrial ones

    Attachment 279264

    Ok, if you could have one of these in your shed, what boat stuff would you print?
    Hi Woodeneye, meant to post to this, but have been quite busy.

    Boat related things to make on a 3D printer:

    Swivels for a competition style oar set-up:


    As designed:

    As printed:


    Fascinating to play around drawing on the computer and then be able to produce a 3D object from that.

    Currently, I'm also working on a folding kayak and rowboat concept involving 3D printing. Stringers of carbon or glass composite tube that sleeve together with bungee cord inside, cross frames of 12 mm ply (cut on a CNC router), connection between the two with plastic 3D printed connectors.
    Because you're free to design non orthogonally, you can have each connector matching the exact angle the stringer meets the cross frame and have a wider, more secure connection than otherwise. Cross frames mainly out of ply makes sense as its cheaper, stiffer and half the weight of the solid injection moulded plastic the commercial folders use.

    A couple of pictures to give an idea:

    Cross frames of ply in place:



    3D printed connector. Note the semicircular hole that snaps onto the stringer at that point is not orthogonal to the plane of the ply cross frame:


    Actual connector in place on a carbon stringer:



    3D printed connectors in place on a ply cross frame:


    Still work in progress, need to get some less interrupted time on it, writing the software to get all the angles where each stringer meets a cross frame and have that feed through to the 3D shape of each bit is the tricky bit.

    Once it all comes together, I should be able to send a cutting file to the CNC router people and have a box of all the ply bits come back, send the files for all the plastic bits to my sister (who has the 3D printer) and get a box of plastic bits back, order the glass or carbon stringers all made up with sleeves and put the frame together in a couple of hours. Skin will take a little longer to do, I haven't figured out a quick way to glue/sew a skin together with zips and everything.

    Ian

  15. #149
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    Quote Originally Posted by PAR View Post
    I'm inclined to agree Mic, two foils will be the fast ticket and along with weight reduction, which is a continously on going engineering issue, control and foil innovations will be what's next.
    Couldn't one foil work? One less appendage in the water = less drag. The tiller would be central and operate a rudder on the foil so tiller and mainsheet would probably just be in the opposite hands. The lifting foil would be narrower, but longer, maybe a delta shape, so it would be more like a narrow skiff to sail as some beam is given away. It would be a pig to manage, initially anyway, but the Mothies are super-human so they should be able to do it.

  16. #150
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    It is a "balance" - one foil will be less draggy, but if the control surfaces have to work overtime to make it fly consistently then that's greater nett drag.

    It's like saying a non foiling boat without a rudder will go best upwind (which might be arguable) but a rudder lightly loaded a good distance away from the centreboard minimises the control forces and thus drag of the system.

    Ian Ward's monofoiling moth uses the very small bow foil as a sensor/wand to set the attitude (pitch) of the hull and therefore the angle of the main foil. No rudder foil. It wasn't as fast as a skiff scow - wide stern stops the bow from going up to initiate foiling. But Ward said faster than most monohulls and many cats.

    ward monofoiler scow moth.jpg

    MIK

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