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Re: How can the Mac 26X sail close hauled better?
Posted: Tue May 18, 2010 7:24 pm
by Hamin' X
On an X, the center of resistance moves aft when the board is partially raised. This will have the effect of moving the bow leeward with consistent sail trim. Not sure what is going on in your case, Opie. Perhaps the reduced angle of heel is interacting with your particular trim/tuning?
~Rich
Re: How can the Mac 26X sail close hauled better?
Posted: Tue May 18, 2010 10:20 pm
by jschrade
How much of a difference is there between a 26X and 26M when it comes to sailing to windward?
7kts of wind is not all that much and often folks sheet in too tight and the sails cannot get any lift. Try slacking the sheets, just a bit, fall off to get some steam and then slowly head up and sheet it. As was mentioned you should sail till you start to luff and then fall off just a bit. When you get puffs, head up just a tich to stop the heal and point higher. If pointing high is your objective, you should be riding the luff line which is a very comfortable point of sail. It's also a great way to learn to steer your boat as if you fall off too much you will start to heal (quite a bit in stiff winds) and then an over-reaction will cause the sails to luff: Heal, Luff, Heal, Luff ...
Coming from a Hobie 16 (which isn't a great point but a great reacher also) it's seems about the same to me. With the exception that the 26M is ridiculously easy to TAC in comparison.
Lately, we have had 10-15 know winds and when I push it my apparent wind is pretty much on the nose.
Jim

Re: How can the Mac 26X sail close hauled better?
Posted: Wed May 19, 2010 4:24 am
by opie
Rich,
Not sure what is going on in your case, Opie.
I am just following my X factory manual, and it works...
I almost ended up on the rocks one time before I read the above. I was using main only and could not tack at all. Granted, tacking without a foresail is not easy anyway, but with main-only and a full CB it is a roll of dice, at least for me. I bet those with racing experience can do it.
Anyway, my rationalization for what is going on is this sketch.

Where the pivot point moves under the mainsail when there is no foresail and needs to be matched with the CB partially down.

With a foresail the full CB down would be proper as the pivot point or what I call the center of effort would be moved forward to the CB vertical point and matched properly. I am not sure about a M boat, are both sails are needed to tack well with an M's daggerboard?
Rich, if I am saying something wrong, please advise, as I really want to improve my sailing. (I finally get to go to the ocean at Wrightsville Beach this week after 5 months of lake only boating.)
Re: How can the Mac 26X sail close hauled better?
Posted: Wed May 19, 2010 8:20 am
by SailingontheRiva
opie wrote:Riva,
Please let us know how much CB you have down while you are using the main only. I find that I can not tack with more than 8 inches of CB line down, that gives about 33% of board down.... By using partial CB the center of effort moves back enough to make a tack. With full CB and using main only, I can not do a thing. What do you find?
8" of centerboard sounds about right. I also find it very difficult to tack with the centerboard fully deployed with only the main up. The boat has a lot of weather helm when you sail into the wind with only a little bit of centerboard but I find it sometimes works better for a close haul in brisk wind (~15Knots). I'll bear off the wind to pick up speed and then quickly tack. It might be noted that I don't carry a lot of gear with me so weight might be a factor. (???) Just my two cents...

Re: How can the Mac 26X sail close hauled better?
Posted: Wed May 19, 2010 2:19 pm
by Scott
On a low pointing boat like the mac you can get enough speed to tack in light winds even under main only. Sometimes you may need to release the sheet on the main a bit as you come across the eye. Fall off more than you intend and sheet in until you regain enough speed to point up again.
Anyone that has sailed a hobie knows this one.
Re: How can the Mac 26X sail close hauled better?
Posted: Wed May 19, 2010 10:16 pm
by Hamin' X
Opie, you are confusing center of effort (COE), with center of resistance (COR). COE is where the push is, or what the wind is affecting, COR is what is preventing the side slipping. The centerboard (CB) only affects resistance and sails, effort. When sailing on main alone, the center of effort is moved aft and requires the CB to be raised a bit, in order to move the COR aft to balance the boat. But, this should not allow the boat to point higher, only reduce weather helm, which is the tendency for the boat to want to turn toward the wind. To make the boat point higher with more velocity make good (VMG) to your target, you need two things: More power from the sails and less heeling. This requires a balanced sail plan and flatter sails. Tightening the backstay to induce mast bend will help flatten the main, as will tightening the boom vang and outhaul. If you are heeling too much, you probably have improper trim, or blown out sails. As your manual says though, when sailing to windward, the CB should be fully down, unless you are on main alone. in that case, you need to pull the board a bit for balance, but you will sacrifice pointing ability, or you will side slip to leeward during the tack. Neither of which is desirable.
~Rich
Re: How can the Mac 26X sail close hauled better?
Posted: Thu May 20, 2010 12:05 am
by delevi
You will not point higher with just the main. You might get your bow closer to the wind, but you're not really sailing, and your speed will be mostly leeway. 7 knots wind, I would use the 150 genoa vs jib. It won't get better with the jib. It is not uncommon to not be able to sail as high in light wind. Close hauled apparent wind will be 30-35 degrees when pointing 45 true in 7 knots wind. 45 apparent is a close reach (maybe 65 true.) As Scott pointed out, speed first, then point. Max board for pointing. The trick is to get the wind and sail trim to get you close hauled, not force it by steering up. Fall off, build speed, trim in a bit. Let the boat come up on its own. Trim in some more, keep going as the apparent wind builds and moves forward. Keep trimming until all is tight. 50 degrees true with the genoa is quite good. With the jib, you may get a few degrees better in light air. Should be able to hit 45 with jib but much slower in 7 kts breeze. Subtract 10-15 degrees between true & apparent. Results may vary. I do sail an

with various mods, but the technique would be the same on any boat.
Leon
Re: How can the Mac 26X sail close hauled better?
Posted: Tue May 25, 2010 9:01 am
by Gazmn
Boy you guys are good
I have to try these options as Stall & Fall are my culprits @ close wind.
But nothing beats 90 ponies or whatever magnet you got back there
We're
PowerSailors....
The name says it all..

Re: How can the Mac 26X sail close hauled better?
Posted: Wed May 26, 2010 3:04 pm
by ronacarme
Opie....I agree..Our 2001 X, in winds high enuf to require mainsail only, sails nicely to windward and tacks easily and has a balanced helm, with about 3/8 of the CB line let out. Center of effort is positioned aft, so center of lateral resistance has to be correspondingly shifted aft.
If the wind drops enuf to set the working jib, our helm balances with about 7/8 of the CB line let out. Center of effort is thus shifted forward, so center of lateral resistance has to be correspondingly shifted forward.
I have never sailed an M, but the helm balance of our old 1988 D seemed less affected by adding or dropping the working jib...maybe because the D daggerboard had a wider chord the X centerboard and so was more stall resistant?
Ron
Re: How can the Mac 26X sail close hauled better?
Posted: Fri Jun 04, 2010 12:57 pm
by opie
Rich and Leon and others,
Good tips and explanations...
Here is a trac-pic of a brand new M and my old X sailing in the Atlantic near shore. One track shown, mine, but we were together.
Ignore some of the other points of the tracks as we were fooling around some and the broad reach back to the jetty (the furthest south track) was just angled to make the sea buoy before bringing down the mast. Too choppy in the inlet to sail between rocks in our opinion.
My point is, on two reaches shown upon returning south, we both could only do 240 true in 180 true wind before luffing as shown on pic below. I will continue to re-read your suggestions and try again next time. Maybe someone else could post some trac-pics of better close hauling toward 50 degrees with proper trim....

Re: How can the Mac 26X sail close hauled better?
Posted: Fri Jun 04, 2010 1:29 pm
by Catigale
Opie- is that main + jib or main + genny ??
Re: How can the Mac 26X sail close hauled better?
Posted: Fri Jun 04, 2010 6:10 pm
by opie
I apologize for stoking the fire as I believe many significant suggestions were previously made. Whether main only or +jib or +genny, there does not seem to be a unanimous recommendation above. My point I think I was trying to make, other than showing off some Goggle skills, is that 45 degrees to the wind on a haul is the gold standard. Some above can get there and others can get almost there, to close to 50 degrees. My getting to 60 degrees is not all that bad for non-racer types, and it is alot better than where I started this spring at 70 degrees or even 80 with non-trimmed sails and the 150 genny on the outside of the shrouds. I'll keep trying to improve. I still would like to see some member's GPS tracking of a Mac doing 45 or 50 degrees true on a reach or haul (or a 'fetch' for the UK'rs).
Re: How can the Mac 26X sail close hauled better?
Posted: Sat Jun 05, 2010 4:03 am
by Catigale
...you cant just report your compass heading either since slideslip will deviate your true course made good to a larger angle of the true wind.
Opie - with my main plus genny, ive never done better than 50 to true wind - but I suck as a sailor, to put it bluntly
Re: How can the Mac 26X sail close hauled better?
Posted: Sat Jun 05, 2010 8:15 am
by opie
Exactly!
That is why an accurate wind reading is necessary from a non-moving position and then use gps true tracks applied over a Google Earth image. What you see that way is true readings for course covered and not the boat-heading reading that does not show true course.
Re: How can the Mac 26X sail close hauled better?
Posted: Sat Jun 05, 2010 8:34 pm
by Phil M
opie wrote:
That is why an accurate wind reading is necessary from a non-moving position and then use gps true tracks applied over a Google Earth image. What you see that way is true readings for course covered and not the boat-heading reading that does not show true course.
Does it really matter what your true course is?
If you are heading at, say 200 degrees, at 4 knots close hauled, and then you tack and are now heading 350 degrees at 4 knots close hauled, would you not just split the difference (350 -200 = 150 150/2 = 75) The best you can do close hauled, maintaining a reasonable speed of 4 knots, is 75 degrees.
Phil M
