Hey that's right, you have a cutter rig... :-) So yeah, you could relate directly to that example! cheers, John S. On 10/27/2016 11:28 PM, Keith R. Martin wrote:
Hey John,
Yup I hear you.. If I am travelling in the straight on a day that promises a really "righteous" sail in robust conditions I will drop my top down furled asym off the bowsprit before weighing anchor...
Keith R. Martin, P.Eng Serenity, Hull #353
On Oct 27, 2016 10:52 PM, "John Schinnerer" <john@eco-living.net> wrote:
Thanks Keith, that all makes sense...
Another factor re pointing ability is simply the added windage of the extrusion and any jib fabric wrapped around it, including padding (which keeps the sail shape better but usually adds a bit of bulk - more windage - to do so...). Anything adding windage up there affects pointing ability somewhat. And our boats are on the small end of the size range that these furlers fit; if the same diameter furler extrusion is used on an M17 vs. something in the 22-25 foot range, the effect is more per unit of boat on the M17 (and our masthead rig means the furler may have more windage on an M17 than on a larger boat with a fractional rig w/shorter forestay).
Dramatic example of windage effect on pointing: a friend's Corsair (Farrier) 31 tri, with a jib on the forestay and also a screacher on the bowsprit (both furling). Needing a closest possible reach one day, in stiff winds (and some ocean swell, and 3-4' wind waves), the furled screacher just being there at all had a huge effect on pointing ability. We started out of anchorage into the channel and the boat was pointing so poorly right off that we went back to the anchorage, removed and stowed the screacher, and headed back out. Much, much better. Extreme example of course but boy did it make the point about up front windage and pointing ability.
cheers, John S.
On 10/27/2016 08:46 PM, Keith R. Martin wrote:
Hey George,
While I am not a "racing guy" and I don't try to wring out every last bit of speed, I do like maintaining my pointing ability heading into brisk/heaver winds... The CDI furler, pvc forestay extrusion and the jib luff padding all combined adds some distributed weight along the headstay resulting in "deeper/saggier" shape which can impair pointing ability into brisk/heavier winds.
So now with the furler installed I keep the headstay tension & related backstay tension a little higher to help maintain a flatter headstay shape while staying within reasonable bounds for the rigging ( I have a Loos gauge to measure the tension) all the while making sure I keep about 8" of mask rake which seems to work pretty well with my set-up ...
I am not saying that it points as well as a hanked on jib set-up, but in my experience the improvement is noticeable..
The Elliot Patterson website has a decent summary on head stay sag that can be found here -> http://www.epsails.com/Headstay%20sag.htm
Cheers,
Keith
*Keith R. Martin, P.Eng.*
*Burnaby, B.C. CanadaSerenity,** M17 Hull #353*
On 27 October 2016 at 18:58, George Iemmolo <griemmolo2@gmail.com> wrote:
Keith
Your comment on proper headstay tension is of interest as I have a 109 on a CDI Furler. Can you elaborate a bit on the subject?
George "We Can Not Control the Wind But We Can Adjust Our Sails"
On Thu, Oct 27, 2016 at 3:41 PM, Keith R. Martin < keith.richard.martin@gmail.com> wrote:
Hey John,
I had an old 120/130 ish (more than a 109 and less than a 150) hank on
head
sail that came originally with the boat...
For me I think there is a substantial safety benefit in a furler for single handing, which for me is most of the time ..
I now have a 109% on a CDI furler.. I have found it's been a good compromise for single handing the boat up and down the Georgia
straight.
Certainly there have been some lighter wind days in the summer that I
have
yearned for a bit more head sail, but there have also been plenty of days when I have had a reef or two in the main and been very thankful for the 109 on the furler...
As we all know there is a trade off on pointing ability with a furler and particularly once the jib is partially furled hence my choice of a 109
that
allows me to defer "reefing the jib". That said the boat performs and points pretty well with no reef or a single reef in the main and the 109
on
the CDI fully deployed (with some attention paid to proper forestay tension) and has just okay performance when the 109 is furled just a bit, after that deeper furling is not all that stellar ( that's Canadian for
it
sucks).
I toyed with putting a 120 on my furler when I first bought it but
frankly
I had not spent enough time in the boat in the straight to be sure it was the right choice for me... In retrospect while a larger jib on the furler is probably okay for
summer,
the fall and spring shoulder seasons up here generally have no shortage
of
wind, so I think the 109 is a good all season choice for my sailing in
"my
hood" ...
Just my perspective on the choices I made for my boat and the local conditions I single hand sail in.
Keith
Keith R. Martin, P.Eng Serenity, M17 Hull #353
On Oct 26, 2016 7:21 PM, "John Schinnerer" <john@eco-living.net> wrote:
Thanks, that means my 80%-ish Reggie Armstrong jib is probably the
original "high wind" jib. I didn't get a 109% with the boat, just the 80% and the 150% genoa. I mostly single-hand, or have passengers that are not really "crew"
(they
ain't gonna change a headsail under way), so something like the 109
working
jib would be nice to have.
Or, a furling jib...
cheers, John S.
On 10/26/2016 05:41 PM, Judith Blumhorst, DC wrote:
Hi All, > Just for those of you who are curious about sail sizes: > That calculator is pretty cool, but it understates the real LP% by a > small amount. The sail has a curved surface, but the calculator is > computing the shortest straight-line distance between two points on > the
curved surface. This kind of measurement is referred to as "geodesic"
> The
true LP, when measured on the sail itself, will always be slightly > bigger
than a geodesic-space calculation indicates. > Sail design software computes dimensions along the curved surface of > the
sail.
> BTW, according to the original sailplan that Jerry so generously sent > me,
there was an 80%-ish LP Heavy wind jib. Also a 109%, which is a > great,
versatile working jib for the M17.
> Regards,Judywww.HydeSailsDirect.com > > > > On Sat, Oct 22, 2016 at 2:04 PM, John Schinnerer <john@eco-living.net >
wrote:
> > Tidying up my sails, finally doing some measuring... > >> >> My "small" jib is not the 109% standard or working M17 jib, it's >> > quite
a
bit smaller. Here's one calculator I found: >> http://sailingfortuitous.com/apps/jibcalc.html >> >> This and other similar formulas found online put it at about 81-82% >> > (luff
189", leach 160", foot 76"). In between a working jib and a true >> > (like
60-65%) storm jib.
>> >> Also played with the outhaul method shown in that video I posted >> recently. >> Really a good idea AFAICT. Works as clew strap and outhaul both; >> automagically balances the angle of pull on the clew. >> >> And, makes it much easier to move that same outhaul line to a >> > different
reef grommet - no need to tie or untie any knots on flapping sail in
>> bouncing boat. Just loose the outhaul, pull out of current grommet & >> block, >> route back through new grommet & block & make fast. With a boltrope >> > or
slug
>> footed sail of course. This would be a Very Bad Idea on a >> > loose-footed
main...!
>> >> cheers, >> John S. >> >> >> -- >> John Schinnerer - M.A., Whole Systems Design >> -------------------------------------------- >> - Eco-Living - >> Whole Systems Design Services >> People - Place - Learning - Integration >> john@eco-living.net - 510.982.1334 >> http://eco-living.net >> http://sociocracyconsulting.com >> >> >> >> > > -- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
-- John Schinnerer - M.A., Whole Systems Design
- Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com