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FT10 Boat / Rig Upgrades

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#1 b_pattison

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Posted 09 November 2012 - 02:20 PM

Regarding Sailplan upgrade per StayinStrewn:

It's being done.
Ditto removal of the furler. Get longer hoist (.52m / 1.7' longer) for more power and more area in jib for better helm balance (3.8m2/41sqft bigger) by going to a 'MAX' jib configuration.
Coupled with straighter mast setup allows for a bigger (and flatter) main planform and a more aggressive roach that is more readily de-powered.
See comparrison shot from Brian Wood in AUS below.
Bob Pattison

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#2 Snapper

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Posted 14 November 2012 - 10:26 PM

Thanks, Bob. Seems like no one wants to touch this but the bigger jib has been discussed recently. More power, better balance, why not?

-Snap

#3 DA-WOODY

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Posted 15 November 2012 - 02:14 AM

Thanks, Bob. Seems like no one wants to touch this but the bigger jib has been discussed recently. More power, better balance, why not?

-Snap


Rides costing 2X an Up won't like that on bit

Bad enough FT10-M's are faster the way they are

Show sum respect for those who like to buy the more expencive when given a choice

#4 Ship o' Fools

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Posted 15 November 2012 - 04:55 PM

Ditto removal of the furler. Get longer hoist (.52m / 1.7' longer) for more power and more area in jib for better helm balance (3.8m2/41sqft bigger) by going to a 'MAX' jib configuration.
Coupled with straighter mast setup allows for a bigger (and flatter) main planform and a more aggressive roach that is more readily de-powered.

Bob Pattison


The boat has a neutral helm now with a lot of mast rake, how is a bigger jib going to result in better helm balance?

When you are talking about a straighter mast, is the point to make a main with less luff curve and move the removed luff curve sail area to the roach? Will more roach balance the helm and compensate for a larger jib?

Interesting batten position on the main. Why are the battens not perpendicular to the leech?

Thanks

#5 b_pattison

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Posted 15 November 2012 - 07:18 PM

Jibs:
My feeling is the bigger jib is killer fast for the usual reasons with a sweet spot of about 8 true from those that are using them. So this makes it a true light jib and would allow the std class jib to be more of med-hvy...pushing its range up quite a bit...maybe to the point where the class 'heavy' jib isn't needed?

Snap: I guess the reason NOT to have them like this that it removes the furler and requires drops instead of furling. And that's a whole other contentious bit I'll leave to the class. ;)

Helm: Agree about the helm, but on the 10 it is more about keel/rudder/hull, as more and more rake doesn't appreciably add to the helm. The boat feels right with this jib. Maybe the net increase in power at the bottom range helps the helm by loading up the boat in general?

Mainsail: Generally, mains have been getting flatter and flatter, noticeably on rigs like this that can be made quite stiff because of the rig geometry or because of carbon masts. As a result the sail designers don't have to design a lot of luff curve into the sail (so that the sail doesn't turn inside out when the mast is bent).

Stiff rig and tuning allows designers to make the main flatter to begin with (less luff curve) and this results in more roach and the bigger the roach (think fat head) the more the sail will twist easily to depower. Since the girths are fixed by the class rules this results in a sail that is 'bigger' in profile. In this case it might only be 76mm or so, depending how flat/full the one might be.
And as we all know, getting the 10 powered-up, isn’t really the issue, so the need to have a big plump main in light air is over rated.

Battens: Top two are more parallel to the foot. This reduces some of the compression on them and allows the top to twist more readily.
The bottom three are perpendicular to the straight line leech, more or less. Right angle extends the batten further into the sail, so in theory you need less batten length to do the same job as battens parallel to the foot.
This isn’t the reason though. When I design things I try to make sails clean visually and clean from the manufacturing POV. So you notice that all the battens, stripes, windows, do not cross panel or section seams. (had the battens been parallel to the foot, they would have overlapped or been on top of section seams). Doing this means that all of these components can be put on the sail before the sail is assembled. Makes it easier and faster to build and makes the finished product less mangled by machines and hands. And it looks good. Doesn’t always happen like that, but I start with this in mind.

b

#6 Ship o' Fools

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Posted 16 November 2012 - 12:40 AM

Bob, thank you for the response.

s.

#7 Bob Perry

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Posted 16 November 2012 - 05:31 PM

Thanks Ship o:
I was wondering the same thing.
Thanks Bob.

#8 d'ranger

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Posted 16 November 2012 - 08:32 PM

Me too, that is the easiest to understand explanation of the new sail shapes I have seen or heard.




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