Hi Ben ,


It's not really a biplane rig. To compare it to somthing if one
needs to . Its more like a cutter rig. The frame work that it hangs
on predicts the sails cant to windward at various rotatation of the
rig fore and aft.

The biplane rigs try and achieve seperate air flow from both sails
right . The double A frame rig has the two sails working as one.
Having the benifit of sail area with a lower COE and canted to wind
ward to produce lift possibly and or achieving greater range before
reefing is needed.

Todd


--- In harryproa@..., "brag_rotor" <brag_rotor@...>
wrote:
>
> Hi Todd,
>
> Found your pix and now I get it!
>
> Biplanes are fun - I've only ever played with the more mundane
> catamaran with goalposts approach - the sail area needed usually
> forces the hulls far apart due to the sail cord and the need to
> minimise biplane-type interference between the sails.
>
> Very interesting. Thanks.
>
> All the best, Ben
>
>
> --- In harryproa@..., "Todd" <snyder2016@> wrote:
> >
> > Hello Ben,
> >
> > I agree nothing is perfect but building a rigid enough frame,
could
> > even use wing shaped spars on the lower and windward side of the
> > frame to reduce drag of the expose frame. and useing battens as
> > shown on the model would increase stability of sails for your
> > variables mentioned.
> >
> > I'd really like to make the Rig free satnding. But havn't
worked
> > out if the extra weight or the geometry will allow it. If not
only
> > four wires for standing rigging under low loads are needed.
> >
> > Todd
> >
> >
> > --- In harryproa@..., "brag_rotor" <brag_rotor@>
> > wrote:
> > >
> > > Hi Todd,
> > >
> > > ....afaik the 'curved plate' of a 'perfect' foresail is as
good as
> > it
> > > gets, if (and only if) the foil is 'perfectly' aligned to the
flow.
> > >
> > > In an imperfect world (boat movement, gusts, wind shear, sail
> > > cut/twist, crew member errors, dozy skippers) the rounded
leading
> > edge
> > > of a classical airfoil can work well over a much larger range
of
> > > angles of attack - as it needs to.
> > >
> > > ..am still struggling with dialup here, been purging several
> > thousand
> > > spam emails from the system..... <sigh>
> > >
> > > Your rig sounds interesting.
> > >
> > > All the best, Ben
> <snip>
>