MacGregorSailors.com

I would think that if you use the genoa cars for the working jib you will suffer from a heap of leech flutter at best, moving the cars forward on the cabin top allows you to pull the leech down at a more acute angle tensioning the leech.

I would think using the genoa cars the top of the jib would be allowed to open spilling wind,but im no expert

sailboatmike wrote:I would think that if you use the genoa cars for the working jib you will suffer from a heap of leech flutter at best, moving the cars forward on the cabin top allows you to pull the leech down at a more acute angle tensioning the leech.
I would think using the genoa cars the top of the jib would be allowed to open spilling wind,but im no expert

Thanks BOAT and Mike.... I hope my Sailmaker has not got this wrong ...will keep you posted.

All the best.
Neo

I agree with Boat and sailboatmike. I use my working jib exclusively and always run the sheets from the tracks on top of the cabin. I do move the cars forward for light winds and aft for heavier winds...or, when lazy, just put the cars in a middle position and leave them there.

To use the Genoa cars was at the sailmakers request/recommendation, not mine. They are a repeatable sailmaker so surely they would have modified the sail to match? .... I know the sail area went down slightly so I'm assuming the clew was set higher up, like a Genoa, although I know a Genoa has a greater reach (around the stays).... I know I'm going to lose sleep over this.... Maybe Judy can share her thoughts on this?

All the best.
Neo

Sails can be designed for where your sheet blocks are. I a 100% is designed to use the aft blocks the clew is going to be high. If you are having a sail made and looking for the easiest way to do it that is probably ok for you. However you will be giving up some pointing ability not having one designed to fly off of the fwd blocks.

Thanks Grady.

I have questioned this with the sailmaker and here's their response....
"It’s important to design the clew on basis of correct genoa track measurements. The optimum sheeting point can be seen with a virtual line starting from 50% of luff down through clew and ends up at the right position of sheeting point position. We have designed the jib to match your tracks.

I also asked if the sheets should be run inside or outside the stays and their response was "The best is to test it on board"

I can't say I'm happy with their reply but I guess I'm stuck with it
I laid the new Jib over the old Genoa last night. The Clew is much higher but with the overall shape I'm guessing the sheets will be inside the stays.

All the best.
Neo

Check the foot length of ur Jib , did they make u a 125% Jib , because the 100% jib sheets should b run from the front tracks on the roof , think of the sheet carrs as a car gas pedal start at the rear slow "depower" move forward to accelerate "power-up"

I believe Judy B. wrote an article on here somewhere that the 125-135% jibs will not work or sheet well on the mac,s because of there front & rear track locations unless u install 7ft genny track,s on the cabin roof like I have done or u could add another 2-3ft track midships which is a lot of work
http://i844.photobucket.com/albums/ab1/ ... 010012.jpg

http://i844.photobucket.com/albums/ab1/ ... 010011.jpg

http://i844.photobucket.com/albums/ab1/ ... 010009.jpg

If u have a 125-135% jib an easy place to add a 2-3ft midships genny track is on top of the plastic strips for ur sliding hatch , by using my method u can use the already existing holes that r there , the deck is already re-enforced there & is very strong, in this pic below if u were to mount them just in front of my dodger fittings u,d be fine depending on wither u had a 125% or 135% jib

http://i844.photobucket.com/albums/ab1/ ... wjkxcr.jpg

U could install 2-3ft genny tracks in that location starting just past "aft" of the jib track,s behind "aft" of the foot blocks
http://i844.photobucket.com/albums/ab1/ ... 010016.jpg

Just thought I,d throw that in there as I know some guy,s do have 125-135% jibs & have sheeting issues as per Judy B. explanation .

Now do u have a 100 or 125% jib

J

Hi Highlander,

No my new Jib is supposed to be 100% .... If I get lots of Leech flutter would I still be able to use your great idea of "midships genny track"?

All the best.
Neo

Someday I might go to a working jib (i dunno) but if I ever do go to a working jib I will not use the standard off the cabin tracks - the day I go down to a working jib is the day i will have a self tending jib - only one jib sheet - not two. If I am going to downgrade to a jib I want to get something in return. I will dump the furler on that day too - too much hassle on the trailer. I'll get a hank on jib that is self tending with a single sheet line and then i will even be able to program tacking maneuvers into the auto pilot and and not need to wake up to tend the sails when the AP tacks the boat for me!

That'll be the life!

Neo wrote:Hi Highlander,

No my new Jib is supposed to be 100% .... If I get lots of Luff flutter would I still be able to use your great idea of "midships genny track"?

All the best.
Neo

"Supposed to "B" !! u need to measure how long the foot is that is ur first need to know , then go from there !!

J

There are some exceptions:

There is a problem with the traditional way of measuring sails when it comes to the MAC. Judy can explain this stuff way better than me but in traditional lingo there is this thing called the "foretriangle" and it's just the triangle formed on a sailboat - the three points of the "foretiangle" is the top of the mast, the bottom of the mast, and the end of the bowsprit, (or in our modern parlance the end of the bow). The square footage of that "triangle" is used to determing the size of the sail - if your sail is the same square footage as that triangle then it is a 100% jib. 'Performance Handling Racing Rules' say anything bigger than the boats "foretriangle" requires a handicap based on the percentage of sail greater than the "fortiangle" thus we get these stupid sail sizes like 150% and 110% and so forth. It's all because of the regatta crowd, (a past life I try to keep buried).

But it's misleading!

On a FRACTIONAL rig like ours the triangle if measured from the top of the mast is much larger than the triangle if measured from the spot where the forestay attaches to the mast - so TECHNICALLY we can run a sail with a foot that is LONGER than the distance from the tack to the mast and still be within the guidelines of a 100% head-sail - it's all very complicated because in the traditional world all sailboats were flying their head-sails off the TOP of the mast, not near the middle like we do.

It throws off the whole percentage deal.

That's why my genoa: which is a full 208 square feet, is considered a 150 under PHR rules but in reality if compared with the actual triangle created by my FRACTIONAL rigged fore-stay my Genoa is actually over 180% larger than my "foretriangle" if you take into account that my fore-stay does not go all the way to the top of the mast. It's really goofy. And that is why my Genoa goes all the way almost to the back of my cabin - some guys sailing my Genoa don't even use the tracks 0 they tie their Genoa off the rear docking cleats!!!

So with sails with a foot that big you can throw out all the rules in regards to track and cars - it's every man for himself!

This is exactly the reason I dont want sails made in Australia, Australian sail makers have no idea about Macgregors and from my reading on other forums have a very average hit rate on making good sails.

When you have cabin top jib cars WHY would a sail maker build a jib to use on the Genoa tracks unless it was specifically requested, the sheeting angle has to be all wrong unless the sail cut specifically for them and even then Im not sure how you could trim out leech flutter and stop the twist to close the top of the sail so it wont spill the wind at such a shallow angle of sheeting.


On second thoughts, you could use a tweeker (like on symmetric spinnaker sheets) run through your cabin top jib cars to change the jib sheeting angle some smaller trailer sailors that dont have cabin top jib cars do this to get a steeper sheeting angle, but their tweekers are normally run to the side decks for greatest effect

Have a quick read of this, under ther "Tweakers and Telltales." section, http://ullmansails.co.uk/sail-trim/ligh ... wnwind.pdf

sailboatmike wrote:This is exactly the reason I dont want sails made in Australia, Australian sail makers have no idea about Macgregors and from my reading on other forums have a very average hit rate on making good sails

I agree with you Mike but in my case the Sailmaker is based in Asia. I know for a fact they have made Jibs before so I'm not really sure why they suggested using the Genoa tracks..... Maybe I measured it wrong (I doubt it)? .... Maybe they wanted to save on Sail cloth?

Anyway, fingers crossed that this will come good when she flys ....somehow

Neo wrote:Sailmaker is based in Asia.

Not having gone back through the thread, but have you spoken with Judy? HSes based in the US but the loft is in the Phillipeans (if I remember correctly) Maybe she could get them to ship direct?

Would have loved to have ordered from Judy ... but it wasn't to be