new vision on old camber

Good day,

would like to share with You with my camber tuning

more information is available
http://www.youtube.com/watch?v=omfRe97qzno

Yurij Walavin
ywalavin@gmail.com

But surely you will loose batten tension just when you need it; ie under full load when powered up the shock cord will be stretched (because of batten tension) and allow wrinkles to form.

Thought idea of cambers was to maintain batten pressure (ie hold sail out) when powered up. Thats why they tend to have better wind range ???

Its like using a slight compressible batten. If it works would be easier to do at batten pocket end;just hold them on with shock cord ????

Sail will "tack" easier but be less stable ???

[Farlo]

Interesting. From what I've seen in recent sails, battens are more or less "decoupled" from the cams. This was not the case with soft cambers where battens were pressing on the mast. But now battens mostly support the sail's body while cams give shape to the mast sleeve. Some sails allow you to remove cams and keep fully tensioned battens. Wrinkles may appear on the luff, and disappear under wind load. The sail may change profile in lulls... good or bad thing?? By the way my shophandler advises to keep battens slighty undertensioned, even in high performance sails.

[BelSkorpio]

Yep, that's also what I've read.

Batten's main function is to support the sail body (tension is not that important).
Cams are there to profile the mast sleeve and maintain the shape, also in the lulls. They need of course the tension to stay in 1 position.

I think that what the gentleman shows in the movie could work.
It will make the camber rotation easier.
The tricky thing in this setup is to adjust the tension of the coupling device (close to the camber, like shown in the movie) in this way that the profile/shape of the mast sleeve is guaranteed in all cases (also in the lulls + slightly negative wind pressure). I mean that the coupling device should stay "open" in all cases and ONLY closes (shortening the effective length of the battens) when we really want to tack.

Originally Posted by Unregistered

But surely you will loose batten tension just when you need it; ie under full load when powered up the shock cord will be stretched (because of batten tension) and allow wrinkles to form.

Thought idea of cambers was to maintain batten pressure (ie hold sail out) when powered up. Thats why they tend to have better wind range ???

Its like using a slight compressible batten. If it works would be easier to do at batten pocket end;just hold them on with shock cord ????

Sail will "tack" easier but be less stable ???

Good day, thank you for your comment and reply!

would like to clarify that the main construction idea is seperated tension for batten and camber. Where batten has constant tension in the sale as in old Neil Pryde constructions. But rubber ropes in offered construction WORK ONLY FOR CAMBER. As from photo nr. 1/3 you could see that only batten end rests into shock cord (grey color rope). But rubber ropes with one end pull the camber and with another end rest into the batten end (see photo nr. 5).
As a result the batten tenssion keeps strong and there is no wrinkles inside of mast pocket. The camber pressure on mast keeps in diapozon 20-25 kg for both cases, when sale has full profile and when we change the tack.

Best regards
Yurij Walavin
ywalavin@gmail.com
tel: + 371 2 9 287 473

Originally Posted by Farlo

Interesting. From what I've seen in recent sails, battens are more or less "decoupled" from the cams. This was not the case with soft cambers where battens were pressing on the mast. But now battens mostly support the sail's body while cams give shape to the mast sleeve. Some sails allow you to remove cams and keep fully tensioned battens. Wrinkles may appear on the luff, and disappear under wind load. The sail may change profile in lulls... good or bad thing?? By the way my shophandler advises to keep battens slighty undertensioned, even in high performance sails.

Good day!

thank you for your comments!

"Recent sales" you mentioned ... is it Neil Pryde?

I think that constant / full sales profile is more important when wind is not too strong.

Best regards
Yurij Walavin

[Farlo]

Hello Yurij, I was referring to hard cambers like in North Sails S-type. Recently I had to fix one. The lower cam wasn't rotating at all because of the "drop shape" mast. Removing batten tension did help but only marginally. So I had to grind a few mm off the cam to allow more clearance. What you have made is a kind of adaptive spacer. I don't think the profile is affected too much. One issue may be a looser connection with the wishbone making rig less reactive. Do you feel any difference when sailing in low wind? strong wind?

Hello Farlo!

One my good friend (latvian sportsman, see video) having experience with remade sails in season 2009 (based on my camber cosntruction), when received new sail EVOII 10.7 asked me to remake at once even not taking away the package. Therefore i think everything works well both in strong and weak wind.

Best regards
Yurij Walavin

Good day,

just now remade three sails EVO3 (10.0, 10.7, 12.0) for Latvian surfer Ansis Dale LAT13. Avaible from 04.07 till 09.07 on WF World Cup in Puerto Rico.

Best regards,

Yurij Walavin

Riga, Latvia