Forums > Windsurfing General

Cams don't turn

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Created by Macroscien > 9 months ago, 27 May 2012
Macroscien
QLD, 4115 posts
27 May 2012 7:02PM
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What could be most likely reason that cams don't want to turn.
I just bought s.h. 8 m2 RAM NS sail with three cams and did first trial today in relatively weak wind.
Is that ( ?):
-not enough down haul ?
-not enough out haul?
-battens too long?
-wrong mast - too thick?
I had to use my feet after each gybe to push that stubborn cams to other side as ordinary shaking and pumping did nothing.

Mark _australia
WA, 16825 posts
27 May 2012 5:09PM
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Could be any of the above.
Firstly are you using the correct mast?

Macroscien
QLD, 4115 posts
27 May 2012 7:41PM
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Mark _australia said...

Could be any of the above.
Firstly are you using the correct mast?


Recommended set-up seems to be quite strange for me.
Mast 460 plus 45 extension ( not 490 + 15 you may think)
I guess that mast is quite thick that's low and by looking at angle that rolls are installed on cams I am afraid that housing may be touching that mast not rolls.

fanatic02
NSW, 274 posts
27 May 2012 7:43PM
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mast , i had the same problem with a warp , i actually marked on the mast were they sat , then pulled out the cams and saw how they sat on the mast , they were all way to small, i used a heat gun to stretch the cams apart , now it works beautiful

scarrgo
WA, 169 posts
27 May 2012 5:43PM
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the right mast doesn't necessarily mean the sail will rotate well
arn't the north RAM's ment to be 3 cam ?
anyway a couple of things you can do
1. more down haul (outhaul doesn't really have a big effect but you can go for less which can help with getting the final click)
2. less cam spacers
3. a mast with a softer bottom section, or is it a stiffer bottom section
not sure can't hurt to try both, pretty sure it's softer

there's not much else that has a huge effect on rotation other than making new battens with a different taper but thats getting a bit complicated, i normally try not to resort to that until i am very sure of exactly where the problem is and how i want to improve it

Macroscien
QLD, 4115 posts
27 May 2012 7:50PM
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right, three cams at least but only two zips ( the third cam I could only access though boom incision in the sail)

neilpete
WA, 141 posts
27 May 2012 7:19PM
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Agree with fanatic02.

First of all, do not underestimate the mast!! Although problem might be already solved to replace just 1 cam from another sail. You might be better off with another (reed correct) mast. Just take out the cam and see how they do on the mast on the place where it should be as the sail is rigged. You immediately can see if the cam is too small. I had a similar problem with an NP RS sail. Used another mast in it at first as recommended. Replaced just one cam (the one above the boom) from a loft blade and problem was solved. Now I have put the original cam back and using an X9 mast and works fine.

Having some more wind might be helpful too.

If you have got two cams rotating, ….the third one will follow.

Mark _australia
WA, 16825 posts
27 May 2012 8:12PM
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Macro you didn't say if you are using the correct mast. I don't mean length, the actual model recommended by the manufacturer.

45cm extension may not be right if you use a different brand extension. See other threads...... but for example my Chinook starts at 4cm and you can't get the pulleys on the sail to touch the extension pulleys so I add 6cm to every sail's printed specs to get correct downhaul.

If you have the wrong mast, or are under downhauled then you will find rotation really hard.

Then worry about if the cams are too narrow, then batten length

fjdoug
ACT, 374 posts
28 May 2012 8:29AM
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Hi, i find with my (older) formula sails that if i put too much downhaul it kills rotation.
Backing off the downhaul a little fixes it.
kicking the bottom cam once in awhile is normal for me.

stanly
QLD, 298 posts
28 May 2012 11:22AM
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have the same problem with a 7.8 Naish GP, only in one direction, have got use to giving it a little kick coming out of the gybes.

28 May 2012 12:52PM
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Hi Macroscien

The answer is "simple". Your mast is to thick and restrict the camber to rotate and in the same time the distance is less from where the camber push on the mast to where it sits on the leading edge. (from the thicker mast pushing it back)

The North Mast made for those sails was a lot more tapered / drop shape.

Best suggestion if you keep your current mast might be from Fanatic02, that used the heat gun to "open them up a bit more" and if you can sand a bit of the back of the cambers,,





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"Cams don't turn" started by Macroscien