raceboard sail

[Remi]

Hi Tonymatta,

Sorry for the late reply but just arrived in Peru.

I use this sail to developpe the new Phantom Race 380 and use a Red Line 530 and the cams rotation is really nice. Perhaps your RSX mast is bigger or you have too much tention on the battens.

I use this sails easily until 20 knots, after you can be faster with an Overdrive 8,5.

All the best

[tonymatta]

Thanks for the Reply Remi

I have baught the redline 490 mast as recomended for light sailors. I tried it on the sail today, but I still cant get the rotation without pushing the lower batten with my hand or leg.

When I pump the sail, the top battens rotate but come back again because the bottom one won't go.

I tried loosening the batten tension but it only added wrinkles in the sail without assissting rotation. I also tried the boom in the top and bottom clew holes but no difference.

Does it matter what base extension is used? I am using a North Powerx extension set on 20. its maximum setting is 42. I wouldn't have thought that 12cm extra would alter the mast curve much.

[Roger]

Hi Tony,
Not sure if the longer extension is the problem, but I've seen quite a few sails, over the years, that had exactly this problem.
The combined bend of the mast and the extension is way too stiff, and if the top of the extension is anywhere near the front of the bottom cam, you get rotation issues.
Do you have an shorter extension (like a 26 cm) that you can try?
That might just take care of the poor rotation of the bottom batten.
Also, it's never really a good idea to put too much extension up inside your mast as it does affect (marginally in some cases, alot in others) the overall mast bend curve.
I'm looking at an older NP XT26 (Matrix 2000) extension at the moment, and if I set the ring at 20 cm, I measure 19 cm to the top of the extension.
From the top setting on this extension (26 cm) there is still 13 cm (non adjustable) to the top of the extension.
If you have a 42 cm extension, and it has the same 13 cm of non-adjustable area above the top setting, you would have 13 cm +22 cm (42 cm - 20 cm= 22 cm) or 35 cm
up inside your mast.
Does the bottom batten on the Severne Raceboard sail come anywhere close to 35 cm from the base?
If so, I think you would be alot better off (rotation of the lowest cam) and also you would avoid "point loading" the mast at the top of the extension by using a shorter 26 cm extension.
Mast won't bend at all in the area where it ovelaps the extension, so the mast will want to bend alot more right as it comes past the end of the extension, thus causing significant "point loading" in that area. Add the cam on top of it, pushing in the opposite direction, and you have a good recipe for a broken mast.
Hope this helps,

[tonymatta]

Hi Roger, Thanks for the comments. Can always count on you.

I don't have a shorter extension at the moment.

This sail has only five battens so the first one is fairly high. It is about 90cm up the sail. With my extension, I have a 12 cm minimum mast penetration so I have 34cm of extension inside the mast. The first camber is about 36cm from the top of the extension.

I found the comments below on a previous thread about mast rotation. I have sent Jesper Orth a private message as well to confirm his view on it. Do you think the same remedy would apply in this case? Also will it cause any harm to use the sail without the camber inducer in place?

"7th September 2006, 03:13 PM #2
Jesper Orth Member Join Date: Aug 2006
Posts: 37 RE: Severne Overdrive 2005 rotation problems
--------------------------------------------------------------------------------
....... Take the camber out of the sail. Cut with a hacksaw 3-4 mm of the camber end that is pressing against the camber tongue/ and panel inside the luff sleeve. ....

[Floyd]

Hi everyone and happy new year.
I`ve haven`t used or rigged mentioned sail/mast combo but had exacly same problem with a Gaastra GTX. (And a Tushingham T.Bird)
Did find (especially with Gaastra) that by setting extension about 2 cm longer than usual and NOT downhauling any harder bottom batten rotated far easier. Think its to do with the angles downhaul rope makes with respect to mast.
Using exactly correct length and fully down haulling (Sp?) pulls cringle in towards mast. If ext. is a bit longer cringle can be a little away from mast but still be correctly down hauled.
I know overall length of rig is longer but find with both rigs mentioned its worth it. (I also leave bottom batten very slack ; prompting folk on beach " your bottom batten is too slack !!!) (Which it is but entire sail rotates easier)
Good Luck

[tonymatta]

Hi Floyd
Thanks for your suggestion. I did already try setting the mast length longer. I had the experience previously of setting the mast on my RSX sail shorter than the spec and the lower batten would not rotate. Lengthening fixed it but unfortunately not in this case. I also tried more and less downhaul without success.

[tonymatta]

To Remi

I got a respons from Jesper Orth saying that it was a starboard not Severne product and that I should address the concern to you.

I don't believe it is a good idea to cut the camber as suggested in the quote above because the camber doesn't have much plastic in the sides(I guess for weight). I have tried triming a little off the sail shoulder where the camber sits and have had some improvement in Rotation.

I can now get it around with a hard pump or two. Will it improve more with cutting more or is this of limited benefit only?

I can get it back to original with spacers if necessary but I don't want to cause irreparable damage to the sail. Help Please!!

[tonymatta]

Dear Remi

I am still waiting for an answer to my last question please.

should I trim more from the sail shoulder where the cam sits to help the cam to rotate better?

[tonymatta]

waiting.... waiting.... waiting...

[Remi]

Hi Tonymatta,

Sorry but I was busy with 2010 boards.

I think your main problem come from the batten, a stifer one must be better, but anyway next I am working on the next VO2Max sail and will take car of your point.

All the best