GRF's rig school

Originally posted by turnturtle 2011 then Nessa... btw, clear your PMs....!

Cleared!

Both these boats would be good at the Billy No Mates: fast singlehanders only.  Does anyone know when it is next year?

i am just laughing about myself , was getting angry reading al the
stuff this grf bloke was posting until this last one on how to measure
mast bents and design luffcurves...and than i understood that he did not
have a clue , no point in getting angry.he really does not know what he is
talking about..and this is not trying to be offensive , in my eyes is just a
plain fact...to optimize sail shapes nowadays the best saildesigner use
cfd codes ...as well as wind tunnels etc...defyining so the the flying
shape that best suits a given hull shape and boat , taking into
considearation the moments of inertia of the mast, ie the bents, hull
shapes have different drags and righting moments as well as
displacements etc...and than are even able to have a vpp once they get
the data from their cfd codes.to see which shapes really perform best and
in which conditions.once done that you have programs tha calculate your
design shape that has to take into account the stretch of the sail cloth as
well as the effect of the loads onto the sail.we did a bit of that with north
sails....but specially in dinghies the fine art of getting the last little bit of
performance out has his experts and really good sailors and coaches now
and suggest how to go a little further. that is why finnsails for example
have tailored luffcurves to match mast bents to the millimeter.unstayed
masts are even more difficult to get right because they bent sideways
ande fore and aft at the same time....so according to the type of mast a
serious effort of making a one design rig that works , apart from needing
competent sail and mast designers , as well as competent sailors helping
the development , needs also constant monitoring of the consistency of
quality of masts and sails. to get the ideal flying shape once having a
given luffcurve you need very equal mast bents.we have set a tolerance of
about2% mast bent with our supplier, and measure bents the same way
we do with finn masts , richard lovering , our choosen sail designer was a
pleaure to work with and performance seems really good..a py of 950,
even though i think a bit higher will be more appropriate, that we are
using right now is a great achievement for a really wide and stable and
short boat like the d one.... now onto stayed versus unstayed mast. the
stayed mast is all in all more stable , has got less tip fall off and is stiffer
, limits the range of the boom as well as has a bit more aero drag
because od schrouds etc, but for me ends up having less performance
than a stayed mast on a sitting out singlehander , and i explain you why ,
with the increase in wind with he given sail you want to get a flatter
profile as well as more twist , in a sitting out boat the uprighting you have
is very small so sail shape must be really flexible and adapt to wind
changes a lot because if you are not able to depower you end up having
to use a too small sail for light winds......so you end up designing sails
with realtively more luff curve than broad seeming than normal , because
tha mast by deflecting will automatically flatten the sail...and get you the
desired twist.that is really the fine art of making a rig for a sitting out
singlehander...that is the fashinating learning curve that finnsailing
makes you go through   and by playing around with mast bents broad
seeming , luffcurves ,getting the last little bit of peformance out for a
given boat.....remember the hundreds of days spent sailing my finn trying
to squeeze tha last litle bit of performance out , and than bulding the first
carbon mast ,mooving onto the wing mast from dacron sails to plastic ,to
prestretched spectra and tha back to membranes with kevlar to tecnora
etc only to find out tha designing sail for the ac was not that different all
in all ....some sailors through years of training develpope a special eye for
shapes ... in th uk you have david howlett....other than that among the
best around you have luca alias myself...and that is why the d one goes
so fast...you can believe what i say or not , but i know my value , anyhow
you can get independent assessments.....sometime people think i am
mad...but not very many good sailors think that i do not know my stuff.
one last thing the gnav versus a vang lever like we have is crap. a lot
heavier , you also need to make the mast heavier and more aero
drag.......grf complains about the cottage indusrty standards of dinghy
designing....immagine how i feel having to read all the totally
incompetent bs he puts on posts abusing the patience of people...i never
tried to expain how a nuclear reactor works...well he shows as much
kowledge as i have in nuclear reactors, in sail design, ie zero...and
reading more books will not help , the first school for it is sailing and
sailing and more sailing.and for that is too late. i have gone sailing today
....waiting with a glass of wine to the usual incompeten abuse coming at
me..laughing.. all the best luca ps by the way we have choosen the
same sailmaker as rs ...hyde , because we think that they offer great
quality for money....we have though gone expensive on the rig ......and
choose a complicated path to get performance, but really rewarding.in the
end ...try and see for yourself how a well developed rig feels.

Originally posted by winging it Originally posted by turnturtle 2011 then Nessa... btw, clear your PMs....! Cleared! Both these boats would be good at the Billy No Mates: fast singlehanders only.  Does anyone know when it is next year?

Had a quick look 2010 dates not published yet.

Tim

Holy crap - the forum changed P-I-S-S-E-D to "peeved!" Hilarious sh*t!!!!

Thanks for the laugh Y&Y...

f**king off is great fun - but different strokes for different folks, right.
Understand that my brother-in-law is a HISC lifer, so I get it - but damn
does it crack me up. Carry on!