Well with all that kite experience you of all people should now where I'm coming from but apparently not. Buggies roll on bearings Kite surfing you push through water big difference In power needed and control well maybe not control but definitely power required on average.
Maybe you need a better kite or better tuned. I can tune my surfkite leave and go pee just by adding a few short pieces of bungee. Whats that have to do with a fixed wing? I can stand with a 16meter in 30mph winds and not get yanked around by changing AOA of kite.
Scaled effect will be alot slower than the model . I can shunt model with out popping the windward hull. But I'm just tring to see how fast I can get going in the opposite direction most of the time. Not so much on how to do a controlled shunt thats not a challenge for me. Plus I'm filming at the same time and the video perspective is not so great so your really not seeing the true performance and possibilities.
Square hulls heeled you would lose the benefit of performance from such hull forms sailing flat both hulls just skimming the water is the performance.
Your issues are appreciated and things to consider sure but not impossible to weed out with the right technology, lay out in design and with a newly learned sailing skill apart from traditional thought.
Todd
--- In harryproa@yahoogroups.com.au, Mike Crawford <mcrawf@...> wrote:
>
>
> I's possible that I'm missing something.
>
> Could you show me how to stall a square/elliptical rig, and leave it
> stalled for a few minutes, even if the wind direction changes or the
> boat drifts? That would do a lot to help me see the safety of the rig,
> and should be easily demonstrated on a model if it's possible.
>
> I've flow four-line kites since the 1990's, so I'm familiar with how
> they power and depower. My favorite thing is to use the kites on a flat
> beach during low tide, flying along on a three-wheeled kite buggy.
> Great fun. That said, I've never been able to just leave my kite alone
> while I get up to pee.
>
> There's also the worry of the momentary shock loading of the system
> during a shunt as the wing turns from one side to another. Your
> "Planning Proa squared" appears to demonstrate this issue, with the
> windward hull popping off the water momentarily during many of the
> shunts. Get hit with a gust at the same time, and the boat is gone.
>
> Which is not to say it's a bad rig. Your tests have clearly shown how
> fast it can be. I just personally have an issue putting this on a boat
> with a stove, fuel, water, head, and passengers.
>
> ---
>
> This is actually one big reason that I'm planning on a proa in the
> first place.
>
> If I dump my current catamaran in water less than 30' deep, it will
> likely cost me between two and six thousand dollars to replace the
> equipment that could get damaged. I love having a boat with an SA/D
> over 50, but it does worry me when pushing the boat. That kind of cost
> figure for a capsize tends to lead to white knuckles when flying a
> hull. Especially if I'm at an angle where dumping the sheets will
> actually increase the heeling moment, leading to a knockdown or pitchpole.
>
> So it's my dream to get a boat of similar speed, but with greater
> righting moment and longer waterline, and a more powerful rig that I can
> always just depower by letting go. Up to this point, you wouldn't think
> that fast and safe could go together with the same boat. But a WTW
> proa, or catprao, can be an impressive design.
>
> - Mike
>
> / /
>
> tsstproa wrote:
> >
> >
> > When you stall a foil there is no load. Thats reason why planes fall
> > out of the sky Or Kites fall back into the windwindow.
> >
> > The key is the no load and when and how to achieve it and when and how
> > to bring it back on with out the sudden snap. 4/5 line Kites do this
> > by controling the leading edge and adjusting aoa with the back line
> > pulling in or out accordingly. If you don't have the experience its
> > harder to imagine the possiblity.
> >
> > http://www.youtube.com/watch?v=LrezrEfQj68
> >
> > Todd
> >
> > --- In harryproa@yahoogroups.com.au
> > <mailto:harryproa%40yahoogroups.com.au>, Mike Crawford <mcrawf@> wrote:
> > >
> > >
> > > The Maltese Falcon is most impressive.
> > >
> > > However, the rig worries me because there's no easy way to depower it,
> > > and keep it depowered without attention/effort, if you're not on a mega
> > > yacht.
> > >
> > > The Falcon is an extremely heavy monohull with full electronic control
> > > of those sails. Need less power? Push a button, and motors roll the
> > > sails in between the fixed arms. If things get hairy, the boat is heavy
> > > enough and strong enough to hang on until the sails are in. While
> > > sailing, electronics will also keep the sails at an optimum angle to the
> > > wind.
> > >
> > > Assuming a proa won't have those features, I'd have to say this is
> > > more of a racing rig, to be used only by those who really know what
> > > they're doing, and are prepared to capsize, than on a boat where you
> > > might go cruising, or on a single or dual-handed distance race.
> > >
> > > Presenting that full face of the sail to the wind during a tack or
> > > shunt is a problem. On a small boat, or a model, it might be fun to pop
> > > the windward hull out of the water during a shunt, and then to zoom off
> > > at the amazing speeds the dynarig is capable of. But what if you're on
> > > a large boat that's not easily rightable after a capsize, perhaps in
> > > high seas with gusty winds? That could be a disaster waiting to happen,
> > > particularly if there's only one person to handle the sail.
> > >
> > > Reefing the sail in those same high seas and gusty winds could also be
> > > a problem. With an easy rig, una rig, or junk rig, you can let the
> > > sheets out, the sail will weathercock, and you can take your time while
> > > reefing, getting a drink, peeing, or tending to an injury or equipment
> > > failure. For as long as you want. On the other hand, the square rig
> > > won't stay weathercocked in one direction, and stands the chance of
> > > presenting the full face of the sail to the wind, even if for a short
> > > period of time.
> > >
> > > Even if the boat does not capsize, shock-loading components to that
> > > level isn't a recipe for equipment longevity.//
> > >
> > > Again, I think the square/dynarig would be great fun on a 20'-er in
> > > warm waters (or with wetsuits), where you could play with the boat like
> > > a Hobie, flying a hull, and righting the boat if things don't work out.
> > > But I couldn't imagine putting that sort of stress on a lightweight proa
> > > in the 30' to 50' range. Putting a boat that size on its side is a bad
> > > day, no matter what happens afterwards.
> > >
> > > - Mike
> > >
> >
>