I picked up a used Duke 5.4m sail and 430cm mast from Simon just before Easter and took it out for a try today. First thing I noticed was I couldn't pop the sail over because the second batten sits at least 2 finger widths in front of the mast (Hope I'm making sense, I don't know the lingo too well). I set the mast foot and boom to the correct size and had full downhaul, so don't know what's going on. I've been told that the batten should sit about half way across the mast to be about correct. Is there a way to adjust it at all? I'm sure Simon will have a look at it after Easter, but I'm just trying to see if it's something simple so I can use it next week.

Thanks
Michael

CJW said...

Need to know a few things:

- What brand mast?
- How loose is the leech (how floppy is the top of the sail)?
- How much outhaul?

I've found that sails rarely rig as specified by the manufacturer, particularly if they have had a bit of use (stretch) or are rigged on anything other than what is specified.

From what you say to me it sounds like one of only two things, wrong mast or nowhere near enough downhaul.

Its a North Silver 430 mast.
Ahh, the leech I don't know right now, it's all stowed.
Outhaul. I set the boom at 480 and on the sail it said give 1cm outhaul for light conditions and 3cm for heavy conditions. I tried all those, and in between and a bit more without it fixing the problem.
I set the mast foot to 10cm (sail spec says 438 +- 1cm ) and downhauled it with a handles till I couldn't pull any more. I guess the sail pulleys and mast foot pulleys were no more than 5cm apart.

I forgot to mention that Simon replaced this batten while I was waiting and fussed over it quite a bit so I assume he's got it spot on in length.

Thanks
Michael

Mark _australia said...

Measure your mast base - come down 10cm from the 10cm hole and is that the pulleys? If so you will never pull it down that far. For example my Chinook extension starts at 4cm (first hole is labelled 4cm and that is where I can downhaul the sail to) so I add 4cm to every sail spec

Picture perhaps?

Makes sense Mark. I just checked my base and the 10cm mark is 10cm mast base to pulley top. Looks like that would have me about 5cm too short on the downhaul where I got it to today. I'll put it up a hole and do a bit of testing tomorrow.

Thanks
Michael

sthandy said...
Its a North Silver 430 mast.
Ahh, the leech I don't know right now, it's all stowed.
Outhaul. I set the boom at 480 and on the sail it said give 1cm outhaul for light conditions and 3cm for heavy conditions. I tried all those, and in between and a bit more without it fixing the problem.
I set the mast foot to 10cm (sail spec says 438 +- 1cm ) and downhauled it with a handles till I couldn't pull any more. I guess the sail pulleys and mast foot pulleys were no more than 5cm apart.

I forgot to mention that Simon replaced this batten while I was waiting and fussed over it quite a bit so I assume he's got it spot on in length.

Sounds like nowhere near enough downhaul. If the sail spec says 438 +-1cm, and you have your extension set @ 10cm, you should downhaul until there is about a 1-2cm gap between the sail pulley and the extension pulley. as a general rule, you don't want any more then 1-2cm gap between the sail and extension pulleys.

That aside, sails often don't rig exactly to spec due to various factors. So you should rig until the sail looks "right". This is fairly easy on the norths as they have the visual trim system on the top panel as a reference. Basically you downhaul until the top panel is floppy up to the visual trim markers.

http://www.north-windsurf.com/deu/nodes/display/pages/sail-technology <<check the visual trim system here.
www.srfsnosk8.no/pdf/rigwave.pdf <<rigging guide, read this!


also, when you have enough downhaul, the front of the battens directly above and below the boom, should as a general rule, be sitting midway on the mast when there is no outhaul on the sail. It's been a while since I've had a north duke, so I'm not sure where it should sit exactly.

As far as outhaul, the fail-safe system is to just adjust it on the water until the sail is just brushing or not quite touching the boom when it's fully powered. As it gets windier just keep adding a bit of outhaul so that the sail stays off the boom. If its super windy that you have to pull the sail super flat with outhaul just to hang on, it's time to change down a size.

Thanks Swoosh and jsnfolk for the extra info and links, very helpful understanding the vts. I posted some photos of what I have done. I tried adding an avi showing the leech put I don't think is will upload properly and I don't have a youtube account. I wonder what to do to if anything, to get that batten back from 3/4 to 1/2 across the mast? Should I pull a lot harder and move it down a bit more (couldn't budge it past the 441cm mark, but perhaps I could put a bit more weight on it but worried something might go bang!)

Edit. My captions didn't appear so this is the description of photos:
1) mast foot set at 10 gives 440cm mast length.
2) Pulleys are 3cm apart in this photo with mast foot at 10, so 437cm downhaul, the minimum spec on the sail
3) At the above downhaul, the batten is still 2 fingers in front of the mast
4)This photo the base is at 15 and the pulleys are 4cm apart so 441cm downhaul
5)With the above setting the batten is 3/4 across the mast. I think it needs to go back a bit further.
6) Avi didn't upload as I suspected, but the leech is floppy to about the light wind mark on the vts

Thanks
Michael

Okey Dokey, I uploaded the leech avi to my picasa site here:
https://picasaweb.google.com/115049943344198541722/DukeSail#5729234559218581346

It is a terrible video, I don't video with my camera very often perhaps I should have filmed it on the ground but maybe you can see how floppy it is. It is floppy through to the light wind mark on the vts.

Thanks
Michael

Thanks swoosh, I'll use that pattern next time I rig up. Thanks everyone, I've learnt heaps!

Thanks
Michael

Oi,yeah I bought a North sail "duke" 6.4 from Simon couple of weeks ago myself.It rigged up well on the 430 north RDM mast I bought off him a couple of weeks earlier.It was so different to use than the Ezzy 5.2 that Carantoc gave me(thanks heaps mate).It was way lighter to uphaul and so much more power for my beefy 100kgs.Good sails from my very novice opinion

Yep put it on 16cm and downhaul it to about where you have it now in relation to the black pastic base, and that will enable you to get about maximum downhaul