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PostPosted: Wed Oct 30, 2013 10:12 am 
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Nohuhu: My 5.0 doesn't have a roller set up, unfortunately. I have a forestay that travels most of the way down and then splits to two and goes to each hull. I'm pretty sure that part is the same. However, my sails have plastic clips down the back end. These clips attach to the forestay by putting them against the wire at a 90 degree angle and the rotating back to vertical. Is yours the same? If so, how then does the action of furling work?

If not, I've been thinking of ways to allow this to happen. My one idea came from the fact that fusioneng uses clear plastic tubing on his stays because he doesn't like tangling line. Here is my idea:
Image

To the left is the sail clipped to the forestay (red line). To the right is the tubing with windows cut and forestay through it. I guess the picture doesn't illustrate much does it lol. Best I could do on an iPad mini.

Basically the forestay will run through the tubing. The tubing will have little windows cut into it to allow the sail to clip to the forestay. Without the tubing, the sail can rotate 360. With the tubing, which will have the roller furler attached to it, the sail will be furlable because it will not allow the sail to swivel on the forstay 360 and so will furl when the tubing is rotated.

This is me thinking how to do this without much knowledge of the mechanics behind normal furlers. I don't know if the above is even necessary or if the top and bottom attached to the furling mechanism is enough. Is that the case?


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PostPosted: Wed Oct 30, 2013 2:58 pm 
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This Nacra has had the jib halyard tension line removed and is hard tied off at the top. I wish it was adjustable at times.

The sail is fully sleeved and slips over the wire,. The foot is tied direct to the furling ring. Like a simple downhaul. It worked loose once in squall and prevented the sail from furling. That was interesting…

I have no reason to disagree with Bobs PVC approach. I've seen it used on much larger boats.

Speaking of PVC, you can consider a DIY alternative to the $1000 harken furlers. Many plans out there

http://www.boatdesign.net/forums/sailboats/roller-furler-jib-43714.html

http://forum.index.hu/Article/viewArticle?a=121513659&t=9190435

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PostPosted: Wed Oct 30, 2013 7:21 pm 
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Looks like this guy did what I was thinking(the PVC with holes for sail attachment).
http://skinnyhull.com/forum/index.php?P ... sg48#msg48

Thanks for the links!


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PostPosted: Mon Nov 04, 2013 7:42 pm 
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Finally got my Nacra sails out of storage. Looks like the jibs all have horizontal battens, about a foot and a half in length, on the...luff? Leech? The side of the jib that's not attached to the forstay. There's three of them. Think it'll be an issue to just remove them? Or should I cut my losses and not make it a roller furling setup? The sail would furl all but a foot and a half...


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PostPosted: Tue Nov 05, 2013 2:30 am 
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Leech. Sounds less than ideal. I would post some picts and seek Bobs advice here.

Easy furling is critical, I think. The cut of the jib and length of the foot will need to be right for the TI. And the position of the blocks, etc. Most folks start with the small Hobie kayak sail as a starting point.

I would personally like to have a small furling genakker or assym spinnaker kit from Hobie, if I lived in the world of my dreams.

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PostPosted: Tue Nov 05, 2013 5:02 pm 
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The red has 3 battens. The blue one lacks the top batten pocket that the red has. The blue is also missing the mid most batten, though the pocket is there. So ol blue only has one batten but was designed to have two (just trying to be clear).

Both sails are the same shape and design otherwise. I would guesstimate that they are about a foot shorter than the TI sail.


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PostPosted: Tue Nov 05, 2013 7:47 pm 
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Big for our boat but I like the bottom sail. Could work if furled and could be fun down wind if you let it out.

Maybe you could lay that over the TI sail/mast for comparison?

Waddaya think Bob?


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PostPosted: Tue Nov 05, 2013 9:56 pm 
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Can and will tomorrow, weather permitting. I placed these jibs on top of the mast and they are indeed about 1 1/2 foot shorter than the TI sail. Not the entire mast but the furled sail. It's been so long since I sailed the Nacra that I had forgotten how big its sails were! I need to get her out again.


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PostPosted: Tue Nov 05, 2013 9:57 pm 
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DM06:
The battens were probably designed in to prevent flutter, you can likely remove the battens from the pockets in order to be able to furl the sail.
If the sail flutters too badly you may need to add a vertical batten (that's what I have in my jib, the back edge has 1/8" fiberglass kite rod sewn into the trailing edge, this wraps around the mast easily when furling, and helps keep the sail from luffing. ( I believe vertical battens are optional on Nacra jibs, when people have a furler).

Actually my wing jib has 17 full length horizontal soft battens that I constructed from an old steel tape measure (the type with a curved tape), they are typically called soft battens. I cut the battens then covered with mylar packing tape to make them waterproof, then just slid them into the pockets. They furl around the mast with no difficulty, yet they keep the sail from luffing. I designed my jib to remain stable in winds over 30mph so there are a lot of battens and re-enforcements in it. In very rough conditions (high winds) I furl the main completely and only sail with the jib alone.

I would initially just take the battens out for now and see how it works, when trying it out if you post some video most of us can tell you what needs to be added or adjusted to make it work.

Supporting the leading edge with a mast will of course help (can be PVC tubing). You will also need a rear stay line because this jib was designed for use on a much more rigid (stayed) mast. Also your clew line will need to pull almost downward (tied in probably in front of the main mast) similar to how it works on your cat. It would be cool if you could rig it to be self tacking.
Because the sail is so large you may need to mount the jib further forward on the bow sprit than where I have mine.

In higher winds (>12mph) you will likely need to furl the jib some or it can bury the AMA and tip the TI over on a reach with both mainsail and jib open full out. My original (non-wing) jib started at around 40 sq ft, and that was a little large, I eventually cut it back to around 30 sq ft and it was fine but I did have to furl it in some in higher winds. If those sails in the picture are standard Nacra 500 jibs, I believe they are around 40 sq ft.
That jib is so large it will likely work like a big genoa in lower winds, and downwind you will be able to set the jib to one side and the main to the other in a batwing setup, so you may not even need a spinnaker (downwind performance will be awesome).
You will find once you add the jib you will be able to point much closer to the wind when on an upwind.

You know what they say once you go over to a jib you never want to go back :lol:
Hope this helps
Bob


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PostPosted: Wed Nov 06, 2013 7:25 am 
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So keeping the sail partially furled I can use this thing as a proper jib, and by letting it out as a genoa? I like your tape measure idea for the battens. Reminds me of those slap bracelets that used to be popular back in the day, except the tape wants to stay straight.

All the rigging is transferable from the Nacra to the Hobie. All I would need to add is a furling line. But it wouldn't be self tacking. The setup includes a line that has no end. A complete circle with no knots(I suck at describing things). Anywho, it has two Harken...block and tackles? Harken pulleys with a cleat on the same housing. One side of the line goes to the other pulley(the bit that I control, and then the other side of the loop goes to the clew and back to the other pulley. I'm sure there was an easier way to describe that...

Anyway. I can attach the two harken jobs at the handles of the outriggers. At the front of the outriggers...or I guess somewhere on the bowsprit frame. Perhaps on the bars that go back to the crossbar? Either of the former ideas would be having the clew pulled aft. The latter would be pulling it more down. Of course, with the two former I could rig up a line between spinnaker frame that would redirect the aft pull to a downward pull...

Not sure how to make it self tacking. Hopefully this thing isn't too big, as I wasn't looking to spend any money on a sail.


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PostPosted: Wed Nov 06, 2013 8:40 am 
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DM06:
I'm sure it will be fine, just remember to furl it a bit in higher winds or you'll be goin over ( LOL). If the TI were a bit wider it wouldn't be a problem, but it's only 10 ft wide vs the Magnum 18 which is 14 ft wide, or the Windrider 17 that is 12 ft wide (both similar boats, and both have bigger AMA's)
I'm thinking if you can get the downward pulling force on the jib control line at around 45 degrees downward pull, you will be fine.
If you look at the front AKA cross bar you will see they have the screw holes pre-drilled into that bar for up to 5 harken cleats, those are the ones I use to control my jib. I actually have two lines, one on the right side for right tack, and another on the left for left tack. The lines wrap around the AKA bar, then feeds back thru the cleat (so it doesn't come un-cleated from the upward force). I moved my mainmast furler cleat closer to the center (just to the right center of the mast), then use the outer Harkin cleats for the jib control.
The fifth cleat (on the left side next to the mast) I use to hold my halyard line so I can raise and lower the jib from the cockpit.
The setup you described will also work fine if I understand it correctly, plus you already have all the blocks and cleats, I would try your setup first.

On my TI everything is controlled from the front seat, and it's very simple to single hand the boat. I have most of the lines extended so if I ever wanted to run from back seat I could, but haven't ever had any desire to drive from the back seat. I feel trapped back there in the back seat, can't hike out or anything, and that main control like likes to take your head off while back there. Once you add spray skirts it's actually drier in the front seat anyway.
Now you have a bowsprit it provides enough upward lift when sailing to raise the bow out of the water, so sailing from the front seat the boat has perfect balance.
Here is a pic of all my control lines and harken cleats.
Image
The blue sail bag on the left is where I kept my extra spinnakers. The white things on the mirage drives are Hydrofoils to help lift the bow out of the water some (don't really need them anymore since adding the bowsprit so I removed them (sittin in my garage for a rainy day).
Bob


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PostPosted: Sun Nov 10, 2013 11:43 am 
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Couple quick questions:

How thick is your flat aluminum with the bondo? 1/8 or 1/16?

I recall you saying you bent the metal by hand but I just want to confirm that. Did you just bend it over the hull?

I don't know much about bondo. I'm assuming its a powder mixed with water to make a paste. Did you wrap the bow with parchment paper or seran wrap so it wouldn't stick to the hull while it dried? Or does this stuff only stick to metal? Would strips of foam padding with stickum on one side do the trick? Could glue it to the aluminum. It's about 1/8 thick foam. No idea where I got it but would have to get more... I'm sure 3M made it...

Do you think 1/16 thickness is sufficient for my aluminum tubing?

Thanks!


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PostPosted: Sun Nov 10, 2013 3:39 pm 
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I used 1/8 x 2 inch aluminum (bought at Lowes). I just bent it free hand using a cresent wrench for leverage and my knee, or the edge of my work bench. I just eyeballed the shape and bent to fit (it doesn't have to be exact at all). You can also use silicone calk to fill the gap. What I did was taped wax paper over the hull, squirted a big old blob of silicone (or bondo body putty) on the hull and places the piece over it, then skimmed the excess away from the edges. If you use Bondo body putty it sets up in ten minutes (body putty is polyester resin mixed with glass fiber (so you have to mix the resin and hardener to get it ready to use)), if you use the silicone it might take a couple days to setup and dry.
On my anchor mount on the back of my boat I ended up gluing that non-slip rubber shelving material (available at Walmart or the grocery) glued to the aluminum with contact cement, that also worked, so your foam idea should be fine. Basically anything to fill the gap and prevent the aluminum from scratching the hull will work.
Doesn't need to be fancy or precise at all. No I didn't try to bend over the hull, I took it off to make the bends, then tried it, then adjusted (like 15 times), I'm kind of perfectionist and tried to bend it exactly like the hull but there are some really fancy compound bends if you want it bent perfect. I finally just bent it close, then filled the gap with Bondo (way easier).
I used 3/4 sq 1/16 wall sq aluminum tubing. The pieces I used were only 4 ft long, that's why the sq tubing only goes to the rear brace, I used 1/8 x 1/2 aluminum bar to go from the rear to the middle of the bow brace. The reason I used the bar stock is it has to have a twist in it to go from the angled brace (the one you made above) to the 1/8 x 2 inch bar that my bow sprit was bolted to (in my case the fiberglass pultrusion), in your case the bottom of the extra 1/8 x 2 piece I see in your pics that you have folded over the tip of the bow (over the lifting cleat), these are the braces that form the truss shape giving the unit it's strength.

If you can find 1/8 thick sq aluminum tubing I think it will be much stronger especially on the bow sprit itself. If you can get the 3/4 sq tubing to slide easily thru 1" sq tubing with 1/8" wall thickness that will probably work ok. But I think you will find that the 3/4 sq tubing wont fit in the 1" sq x 1/8" wall tubing and you will need 1" sq x 1/16" wall thickness with something like plastic sheet glued in to fill the gap like you described (though it would probably work fine with nothing, however with nothing the 3/4" bowsprit will move back and forth and up and down and will likely be annoying with no spacers).

Hope this helps
Bob


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PostPosted: Sat Nov 16, 2013 3:06 am 
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Ok chaps the jib has arrived. A new but second hand Rooster. Looks just the job. I am sending it off to aeroluff spars http://www.aeroluffspars.co.uk/ who are going to work their magic on it.

With regards to the discussion on mounting a bowsprit onto the Ti is there any reason, if the loads are spread well, that I cannot bolt directly through the hull in front of the hatch. I am thinking of using my favorite yakattack rails bolted to the full back plates and probably four 12" ones. Two on each side. Then i will weld up an aluminum brace that will hold whatever i make the spar out of.

I see you both are taking the pulling force of the jib back to the AKA's where the main sail is but suspect that is because you are having a removable system. as my boat is a sort of advert for yakattack i am quite happy with a fixed installation providing it isn't going to fold in half the first time i put the sail up!

Any thoughts

CC

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PostPosted: Sat Nov 16, 2013 7:36 am 
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I think fusion and I are of the same mindset. Neither of us want to make modifications up front there that require hull modification. For me it's a resale thing, and a wife thing. When she gets frustrated with my meddling I need to be able to strip it off and say "what meddling dear?" If I sell I want to be able to sell it stock.

If I was OK with drilling holes etc though, I think I still might do the same as I'm going to do now. I can see the bow buckling at that big ol hatch up front with a jib setup.

I like cap'n chaos's method of attaching to the front aka. I'm thinking of doing a hybrid of his and fusion's setup. Ie. one long tube from front to rear, with the bent aluminum stock and webbing up front to hold it to the hull.


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