Subject: Re: [harryproa] Re: Hoyt rig
From: "Rob Denney" <harryproa@gmail.com>
Date: 3/27/2008, 7:58 AM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

G'day,

Yes indeed.  We have the technology to build unstayed carbon masts
cheaper (and lighter) than stayed alloy ones, even using expensive
Australian labour and paying excess freight on relatively small
amounts of carbon.   Just need to find someone willing to start up the
business.  This is far harder than I thought it would be.

regards,

Rob

2008/3/27 Dale Bolton <dalebolton@rogers.com>:









Hi Gang  The good thing about all these different rigs is that the concept
of unstayed masts could be considered normal in a few years which could mean
that some Asian company will start turning out good size carbon masts for a
reasonable price. Also carbon may come down in price by then



Dale



 ________________________________


From: harryproa@yahoogroups.com.au [mailto:harryproa@yahoogroups.com.au] On
Behalf Of Robert
 Sent: Thursday, March 27, 2008 12:43 AM
 To: harryproa@yahoogroups.com.au
 Subject: [harryproa] Re: Hoyt rig






I was actually referring to the moern split lug called a balanced rig.
 Sorry I did not make this clear. This effectively becomes a Marconirig
 with a square top main and jib. I am not sure why if the slot effect
 is so improtant, modern biplanes have disappeared,
 RObert --- In harryproa@yahoogroups.com.au, "jjtctaylor"
 <jtaylor412@...> wrote:
 >
 > Hoyt will never be more efficient than a marconi type sail set up.
 LOTS of modelling,
 > math, wind tunnels and a hundred years of experience says it won't
 be more efficient. A
 > UNA rig falls in the same camp. I don't think that was the
 inventor's intent.
 >
 > It's all because the the wind slot created by the jib keeps the
 airflow attached on the lee
 > side of mainsail. It creates a coefficient of lift on the mainsail
 to approach 2.0. Doesn't
 > have be a big jib, just enough to create the flow. If the airflow
 separates, CL drops to .7 or
 > worse. When really poor the mainsail luffs. Before that have to
 watch the telltales.
 >
 > A single sail ala Clark "Y" or other similar thin film airfoil
 shapes can at BEST get a
 > coefficient of lift of 1.2. The probability of the helmsman to get
 it all right is low. So we
 > expect 1.0 or less.
 >
 > That applies to all reaches. The game changes when we are running
 at very broad reach to
 > downwind running. Spinnaker or mainsail bagging keeps the
 coefficient of lift to near 1.2
 > or even a little better, due to different ballooning effects which
 to date are not always well
 > understood. Hoyt does have a slight problem with good bagging on
 one tack. Seems to
 > run afoul with the offset mast.
 >
 > What is known is low aspect rigs are more forgiving to angle of
 attack on all points of sail,
 > which keeps performance up to the practical lift limit. Makes
 catboat owners happy.
 > Higher aspect una rigs take more effort to keep shape and angle of
 attack in proper
 > balance.
 >
 > All of this is a nice compare but all rigs offer a different set of
 compromises that have to
 > balance with the motivation and effort of the helm. If you aren't
 going fast enough, make
 > it bigger. Hoyt make it easier to deal with bigger??, then go for it !
 >
 > My personal motivation is really really low........ so will be
 trying rigid wings instead.
 > Might find me steering with my feet, albeit dancing with the crab
 pots. Wing management
 > is a single lever, no ropes, no reef, no sound. Just GO.
 >
 > JT
 >
 > --- In harryproa@yahoogroups.com.au, "Robert" <cateran1949@> wrote:
 > >
 > > -It does have an endplate that should be some improvement over the old
 > > split lug. I don't see why it should be less efficient than the
 > > ballestrom rig, and it remains balanced when reefed.
 > > Robert
 > > -- In harryproa@yahoogroups.com.au, "proaconstrictor"
 > > <proaconstrictor@> wrote:
 > > >
 > > > --- In harryproa@yahoogroups.com.au, "gunnar.westholm"
 > > > <gunnar.westholm@> wrote:
 > > > >
 > > > > The Balanced Rig http://www.balancedrig.com/advantage.html
 > > > > seems stronger and more efficient then the Hoyt rig.
 > > >
 > > >
 > > > I doubt it's more efficient, it's just the old split lug, which
 wasn't
 > > > even more efficient than the lug with mast interference. Though
 Newick
 > > > was going to specify the split lug on one trimaran, and then it
 became
 > > > all top secret aa to why it didn't work.
 > > >
 > > >
 > > > > At least if the main would be fitted with a mast sleeve, like on
 > > > > windsurf and Wharrams Tiki rigs
 > > > > http://www.wharram.eu/photos/index.cgi?mode=album&album=/Tiki-
 > > > > range/Tiki%208m%20GRP/Tiki%208m%20-%20sailing
 > > >
 > > > TIKI rigs seem to do OK and they are very easy to make since the
 > > > correct cut seems to be totally flat. They do have the occasional
 > > > reefing problem in heavy weather though.
 > > >
 > > > I think you could at least fit these rigs to proa though,
 whereas, I;m
 > > > not sure the HBR is a good condidate, though I didn't fully
 think og
 > > > that until I had posted it.
 > > >
 > > > >
 > > > > /Gunnar
 > > > >
 > > >
 > >
 >




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