Announcements
New Discussions
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
5.8 sail tuning #169095
02/22/09 02:59 AM
02/22/09 02:59 AM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline OP
veteran
JeffS  Offline OP
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
G'day I've tried all types of settings but I'm finding it hard to get my sail to stay full in the front 20% of the sail upwind. You can see in the photo's taken yesterday how its luffing, it does this with full rotation or only 45 degree rotation. The only way I've been able to fill it is by pulling on more downhaul that I want and depowering the boat. I was also supprised by the amount of twist, should I have had it on more? but that seems to choke the boat. Anybody know my error?
regards

Attached Files
Nacra sail.JPG (280 downloads)

Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576
-- Have You Seen This? --
Re: 5.8 sail tuning [Re: JeffS] #169105
02/22/09 10:39 AM
02/22/09 10:39 AM
Joined: Dec 2006
Posts: 2,490
On the Water
P.M. Offline
Pooh-Bah
P.M.  Offline
Pooh-Bah

Joined: Dec 2006
Posts: 2,490
On the Water
Jeff,
. . . there are lots of variables. Pay attention to the jib, it is a large overlapping setup on the 5.8NA. Be careful to not oversheet the jib and pay attention to the jib block position, forward vs aft, inbound/out. It is easy to backwind the main on the NA.


Philip
USA #1006
Re: 5.8 sail tuning [Re: JeffS] #169106
02/22/09 10:43 AM
02/22/09 10:43 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Jeff,

It's difficult to tell from those photos but I can definitely see a really full deep shape at the bottom with the draft at or further back than 50% - it just looks like a sail with a bad cut/shape. The boomless sail is a difficult cut to get correct - is that a sail built by Nacra (E/P) or someone else? If you want to try and salvage the sail and get a little more out of it, you might want to try putting a boom on the rig so you can force the foot of the sail out further toward the rear of the boat.


Jake Kohl
Re: 5.8 sail tuning [Re: Jake] #169108
02/22/09 10:52 AM
02/22/09 10:52 AM
Joined: Sep 2002
Posts: 3,224
Roanoke Island ,N.C.
Team_Cat_Fever Offline
Carpal Tunnel
Team_Cat_Fever  Offline
Carpal Tunnel

Joined: Sep 2002
Posts: 3,224
Roanoke Island ,N.C.
Or just move your mainsheet forward on the foot creating more outhaul. It looks to have the track,but I can't tell for sure.If no track try the forward most grommet hole(if it's a class sail)Like Jake said ,the draft appears to be way aft.
Also looks like you need more downhaul,if you loose to much power ,try the other adjustments to get it back.


"I said, now, I said ,pay attention boy!"

The cure for anything is salt water - sweat, tears, or the sea
Isak Dinesen
If a man is to be obsessed by something.... I suppose a boat is as good as anything... perhaps a bit better than most.
E. B. White
Re: 5.8 sail tuning [Re: Team_Cat_Fever] #169133
02/22/09 05:23 PM
02/22/09 05:23 PM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline OP
veteran
JeffS  Offline OP
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
Thank's guys it's not a Nacra sail it was given to me it was fine but it may have stretched. This sail doesn't have the outhaul track on it so I'll try it in the next hole to pull the sail back, I was reluctant to do that as all my reading said to keep it in the middle hole but I can see from the photo's how full the sail is. The jib does a lot of drumming if its not pulled on really tight but when its pulled tight enough to stop the drumming you can feel it choke the boat, is the drumming a sign that the jib is too old? We had a pile of wind about 2 hours after that photo and I found it hard to point or have any speed up wind.


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576
Re: 5.8 sail tuning [Re: JeffS] #169136
02/22/09 07:32 PM
02/22/09 07:32 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
If the jib is "motoring" (flapping making the sound like a motor), the leech has probably stretched. You can probably tape in a couple of small battens (6" or so) horizontally on the leach at those areas and at least make the sail quiet. Sounds like it's time for some new sails though.


Jake Kohl
Re: 5.8 sail tuning [Re: Jake] #169138
02/22/09 08:07 PM
02/22/09 08:07 PM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline OP
veteran
JeffS  Offline OP
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
Thank's Jake I had the feeling that the jib was tired but really have never sailed anything with newish sails, so white with no holes looked good. I'm in the process of looking for a newer 5.8 anyway so I'll just have to find one with good sails.
regards Jeff


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576
Re: 5.8 sail tuning [Re: JeffS] #169146
02/23/09 12:03 AM
02/23/09 12:03 AM

S
Scarecrow
Unregistered
Scarecrow
Unregistered
S



Jeff, does the cunningham on the nacra jib pull the sail up or down (attach to the head of tack)? If its up try a little more of this. The luff looks loose in the photo and lifting the jib even a little will allow you to tighten the leach without flattening the sail.

Re: 5.8 sail tuning [Re: ] #169147
02/23/09 01:31 AM
02/23/09 01:31 AM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline OP
veteran
JeffS  Offline OP
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
Thanks Scarecrow it does pull up, I've been running it looser lately so I'll try more pull on it
regards


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576
Re: 5.8 sail tuning [Re: JeffS] #169149
02/23/09 02:13 AM
02/23/09 02:13 AM

S
Scarecrow
Unregistered
Scarecrow
Unregistered
S



you might also try a longer shackle at the bottom.

Re: 5.8 sail tuning [Re: JeffS] #169159
02/23/09 09:00 AM
02/23/09 09:00 AM
Joined: Jun 2001
Posts: 890
Dunedin Causeway, FL
David Parker Offline
old hand
David Parker  Offline
old hand

Joined: Jun 2001
Posts: 890
Dunedin Causeway, FL
If you're downhauling and the wrinkles won't go away, I'd say the bolt rope has shrunk and needs to be "relaxed".

The rope inside the luff of the sail shrinks and can shrink A LOT, often a foot or more. You want to downhaul the sail material, not the rope. The rope just holds the sail in the track. The sail is only held to the rope with a few stitches top and bottom. Cut those bottom stitches and downhaul the sail and the rope will pull up into the sail quite a bit. Now the sail will slide down an extra foot, smoothing out the wrinkles and correcting its shape.

You'll have to feed a new bit of rope up into the pocket and stitch it in to keep the new piece from falling out. Alternatively, you can melt the new piece and fuze it to the butt end of the old before you cut those stitches. Then when you downhaul it will draw the new bit up into the sail.

Don't let anyone convince you that you pull on the rope. It does NOT need to be continuously strong top to bottom. It's only there to keep the sail in the track.

Look at your photo. You can see the wrinkles and yet your downhaul is tight. 15 minutes will fix it and add 10% to your upwind power.


Re: 5.8 sail tuning [Re: David Parker] #169220
02/23/09 05:12 PM
02/23/09 05:12 PM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline OP
veteran
JeffS  Offline OP
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
Thank's David I should have said that photo was the worst I could find that actually showed the sail luffing. It was just after the start and a puff had just passed through that flattened a 5.7 and A just out of the photo before my wife pulled on much downhaul, it was one of those days where it goes from nothing to full on which was why she grabbed me going upwind. When she pulls the downhaul it sorts out the wrinkles no worries and sorts out most of the luffing so it doesn't show in a photo but it's still there. Chris I added a 6 inch lead to the bottom of my jib to fit in my downhaul arrangement, could the lifting of the jib create this problem?
regards


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576
Re: 5.8 sail tuning [Re: JeffS] #169348
02/24/09 01:37 PM
02/24/09 01:37 PM
Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
Todd_Sails Offline
Carpal Tunnel
Todd_Sails  Offline
Carpal Tunnel

Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
If your jig is 'luffing' when you sheet it fairly tight, move the jib block forward some, this pulls more tension vertically, and puts more tension on the leach, and will often stop the 'luffing', motoring, whatever you call it, it's slow.

And as has been said, it is easy to stall, or backwind the main with the HUGE jib of the Nacra NA's. If so, also move the jib block outward some. It hsould have the 4-way jib system on it, making it an easy thing to adjust.

Good luck, let us know.

BTW, from the looks of the one picture, move the mainsheet block clew forward a bunch, and then play with it to get things flowing right.


F-18 Infusion
#626- SOLD it!

'Long Live the Legend of Chris Kyle'
Re: 5.8 sail tuning [Re: ] #169377
02/24/09 05:25 PM
02/24/09 05:25 PM
Joined: Nov 2005
Posts: 1,203
uk
TEAMVMG Offline
veteran
TEAMVMG  Offline
veteran

Joined: Nov 2005
Posts: 1,203
uk
If you move the mainsheeting point foward on the sail, you may flatten the bottom but you will also induce hell of a lot more twist. the large amount of twist that you say you already have will be a good reason that the boat is not pointing [Pointing is down to jib and main leech control/tension]
It looks like you need to let the mast bend more to take some of the fullness out. i think that the 5.8s go with a 'soft' rig so you can loosen the diamond wires a bit. To stop this bend choking the slot, let some rotation off.
The trouble is, you may end up with a totally gutless boat with no power on this set-up!

New sails time maybe


Paul

teamvmg.weebly.com
Re: 5.8 sail tuning [Re: ] #169396
02/24/09 08:24 PM
02/24/09 08:24 PM
Joined: Mar 2006
Posts: 337
Arizona
AzCat Offline
enthusiast
AzCat  Offline
enthusiast

Joined: Mar 2006
Posts: 337
Arizona
I just got rid of my old dacron on my N5.7, an went to a mylar. I had the same problem with the sails chocking in the heavies. With the main bellying out so far, it chocked off the slot. I couldent point at all. on a reach, in even moderate wind i would be over powered. It was like riding a bronco. New Mylar squaretop = new boat. The sail can be shaped any way you want it. I tightened up the diamonds, added rotation, no more chocked off slot. tons of useable and controllable power.
I think your sails are tired. Look around in the winter, there are some great deals out there.


Auscat MKV 444 A class
NACRA I-20- 440/CATHATKA
Re: 5.8 sail tuning [Re: AzCat] #169421
02/25/09 02:32 AM
02/25/09 02:32 AM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline OP
veteran
JeffS  Offline OP
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
Thank's guys I'm going to have a play with settings this weekend. The main sail was holding a good shape until I started playing with the jib or I may have stretched it. I have the loose diamond wire setup where you can just make the wires touch 18 inches up from the bottom. I'll see what I can do with various settings before the race on Saturday.
regards


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576

Moderated by  Damon Linkous 

Search

Who's Online Now
0 registered members (), 253 guests, and 85 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Darryl, zorro, CraigJ, PaulEddo2, AUS180
8150 Registered Users
Top Posters(30 Days)
Forum Statistics
Forums26
Topics22,404
Posts267,055
Members8,150
Most Online2,167
Dec 19th, 2022
--Advertisement--
Powered by UBB.threads™ PHP Forum Software 7.7.1