I had a new sail made for my Nacra 6.0 NA. The sail is a square top. Ever so slightly smaller in overall area than the original pin head. It's an upgrade, we did 19.9 knts in our first 7 min under way, our fastest ever. We furled the jib shortly after that since the water was freezing and we didn't want to flip.

I'm looking for some help though.

For starters, when the sail is loaded up at all, I can't trim the main sheet without it pulling the traveler up. I have no fix for this that I can think of. It basically inhibits me from trimming the main in any small way.

Secondly, and this isn't specific to the new sail, but when I adjust the outhaul and the top block of the main sheet move fore and aft it greatly changes the angle of the main sheet jaws. So when sailing upwind and the main sheet is angled forward the jaws which are on top of the main sheet get angled down so I have trouble releasing it. When sailing downwind and outhaul is out, jaws are too high. Most the new Formula boats I see have the mainsheet attached directly to the clew of the sail so they must have this same issue?

I'm contemplating installing a boom which would eliminate the latter problem, it would also improve mast rotation as an added benefit.

Let me know your thoughts, ideas. Thanks.



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Nacra 6.0 NA
Ogden Dunes, IN
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Have you split the traveler or mainsheet so it has 2 eye straps where the sheet is tied off to the rear beam? This minimizes slack and traveler movement when close-hauled. This rigging practice started after the 6.0 was built. It is a simple retrofit.

The newer boats have reduced outhaul purchase compared boats built in the 2000s, (I20). Many sailors with spinnakers are not adjusting the outhaul with each leg change. I believe the mainsheet has to get eased to re-tighten the outhaul and in most cases is not worth the adjustment.

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David
Inter 20
Southern Maine
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Have you split the traveler or mainsheet so it has 2 eye straps where the sheet is tied off to the rear beam? This minimizes slack and traveler movement when close-hauled. This rigging practice started after the 6.0 was built. It is a simple retrofit.

I'm not real sure what you're referring to here. I have a 2:1 arrangement on the traveler. its set up just like a hobie 16. Just one sheet tied to the rear crossbar. I couldn't find any pictures of what you describe.

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Nacra 6.0 NA
Ogden Dunes, IN
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here is a photo

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David
Inter 20
Southern Maine
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Oh I see. Looks like a good idea. Wouldn't help me when the traveler is out though. I'll have the traveler out a foot, and I cant trim the mainsheet without the traveler coming up nearly to center.

If I had a boom, I could route the main sheet forward and trim from there like a dinghy or the new A cats... That would help.

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Nacra 6.0 NA
Ogden Dunes, IN
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For starters, when the sail is loaded up at all, I can't trim the main sheet without it pulling the traveler up. I have no fix for this that I can think of. It basically inhibits me from trimming the main in any small way.

What do you mean that the traveler is pulling up? Is the traveler track pulling off the beam? Is the car pulling off the track?


Secondly, and this isn't specific to the new sail, but when I adjust the outhaul and the top block of the main sheet move fore and aft it greatly changes the angle of the main sheet jaws. So when sailing upwind and the main sheet is angled forward the jaws which are on top of the main sheet get angled down so I have trouble releasing it. When sailing downwind and outhaul is out, jaws are too high. Most the new Formula boats I see have the mainsheet attached directly to the clew of the sail so they must have this same issue?

Try flipping the mainsheet cleat over. Where you go upward to uncleat. It is different and I recommend sailing in light/medium breeze to get used to it before you get yourself into trouble trying to pop it down to uncleat by habit. This way, it is easier to cleat downwind when the blocks pivot forward.

I'm contemplating installing a boom which would eliminate the latter problem, it would also improve mast rotation as an added benefit.

I loved the 5.8 and 6.0 without a boom. I would not recommend it.

One thing to look at on the square top, if the head is too big, you will get some funky wrinkle loads through the middle of the sail.

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Scott

Prindle Fleet 2
TCDYC

Prindle 18-2 Mod "FrankenKitty"
Tornado Classic "Fast Furniture"
Prindle 19 "Mr. Wiggly"
Nacra 5.8 "De ja vu"
Nacra 5.0
Nacra 5.8
Tornadoes (Reg White)
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Try flipping the mainsheet cleat over. Where you go upward to uncleat. It is different and I recommend sailing in light/medium breeze to get used to it before you get yourself into trouble trying to pop it down to uncleat by habit. This way, it is easier to cleat downwind when the blocks pivot forward.

I'll try that.

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Nacra 6.0 NA
Ogden Dunes, IN
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I think what he's saying about the travel pulling in...
When the travel is out from center and you pull to sheet the main hard. The traveler wants to move towards the center of boat when sheeting. This can't be stopped completely, but adding more purchase (blocks) will reduce it. The square top on my 5.5 was difficult with a 6:1 and pulling to sheet always pulled the travel back towards center first, then started sheeting the main. Going to an 8:1 helped greatly.

Sounds like you may need a wedge below your cleat on the mainsheet. There are different angles and also risers. Here's an example.
https://www.harken.com/pr…l.aspx?id=5061&taxid=392

If your playing large amounts of mainsheet, you may need to fine tune your outhaul, traveler, rotater and downhaul.

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Ron
Nacra F18
Reservoir Sailing Assn.
Brandon, Mississippi
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Wedge kit, More purchase, both good suggestions thank you.

Does anyone run their mainsheet forward from the rear cross bar like a dinghy or A cat?

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Nacra 6.0 NA
Ogden Dunes, IN
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I can't answer running the mainsheet forward. But did want to mention new 18-20 ft squaretop boats are running 10:1 or 12:1

8:1 is not enough without a boom, and not enough for squaretop (I20/6.0) IMO.

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David
Inter 20
Southern Maine
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8:1 works on 5.5 without boom. Agree with you for 6.0 more is needed - at min a 10:1.
My experience has been a boomless rig is easier to over-sheet because all the load goes into the sail. On a boomed rig, part of the sheet load is transferred down the boom to the mast.

Also if your running the harken travel car on the main (boomless rig) - make sure the sail maker reinforced the mounting to the sail - otherwise a 10:1 (or greater) will potentially rip the traveler track off the sail (the belt rope and few screws will not survive the added purchase power). On my 5.5 sq top there is actually an inserted metal plate in the sail which the harken traveler track bolts through.



Edited by geepaks on Apr 09, 2020 - 01:15 PM.

I went with this:
https://www.harken.com/pr…category.aspx?taxid=1558
The wisdom seems to be to trim the main more with the traveler that with the sheet.
https://owners.aquarius-s…/viewtopic.php?f=3&t=896
https://owners.aquarius-s…/viewtopic.php?f=3&t=914
https://owners.aquarius-s…/viewtopic.php?f=3&t=922
Attached are the late Bill Roberts thoughts on sq tops.
Plenty of time to read presently.
I admit some of that is a bit dense. Bill was like that.
What I have noticed with the sq top ti that the windward hull rises in a more dignified manner in a gust than it did with the pin head. I get a bit more time to react.



Edited by gahamby on Apr 09, 2020 - 03:02 PM.

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'82 Super Cat 15
Hull #315
Virginia
Previously owned: '70 H14, '79 H16, '68 Sailmaster 26, '85 H14T
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I've got a heftier than I would like alum plate in my sail that the "boomlet" bolts through. Good read Gahamby, I've read a lot of guys trim more with the traveler than the mainsheet. I myself set it for a point of sail and trim the rest with the mainsheet. Maybe I should experiment more with trimming by way of the traveler.

Only problem I have now is the cost of those Main blocks! Maybe I'll try and borrow a set of 10:1 blocks from one of the local F18 sailors.

I still am leaning towards adding a boom. Reason being, I had sail maker add a reef point in this sail, but the clew wasn't reinforced as I requested. The Reef would require me to hook the main all the way to the back of the sail on the leech. this will give me too much belly, exactly what I don't want when I need the reef in the first place...

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Nacra 6.0 NA
Ogden Dunes, IN
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As far as adding a boom. Make sure you have room under the sail at the mast for the boom attachment. The boomless sails seem to be longer down the mast towards the tramp (I can see you have this extra sail area from your sq top pix). Check for how much room is available with full downhaul of the main to mount the boom. Then you and your crew can still get under it on a tack? Also the boomless sheeting angle is different compared to a boom rig. Currently your traveler car on the main sits forward or almost above the rear beam. So when sheeting in its pulling the main down and back. On a boom rig the sail tends to sit outward (or behind the rear beam) so when sheeting it pushes the boom in towards the mast (inducing mast rotation). Look at sheeting angle on boomless and boom rigs to see. Maybe you can just make the boom hang-out further than the main.



Edited by geepaks on Apr 09, 2020 - 05:32 PM.

Sheet tension along with downhaul, outhaul and rotation, flatten the sail and de-powers it, every time you blow that main sheet, your your powering it back up. If your dumping large amounts of sheet , that cleat angle is never going to stay where you want it. If your setting the controls for you main and just using your main sheet to sail a N6.0NA your going to work your ass off in a breeze.

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Ron
Nacra F18
Reservoir Sailing Assn.
Brandon, Mississippi
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Because I'm too cheap to pay $600 for 12:1 main sheet blocks. Consider the pictures above and below. Pretend I add a pulley where the mainsheet currently ties off and go back to boom. That will turn my main sheet from 8:1 to 9:1. Then I take the end of that line and attach it to a pulley. That pulley is in turn its own 2:1 purchase system. Now I will have a 9:1 main sheet as well as a 18:1 Main sheet. (If I want 8:1 and 16:1 i can unthread one of the pulleys on the main blocks.) This will give me an optional fine adjust main that I should be able to trim with one hand.

Here's my favorite part:



In the picture above, the grey pulleys are fixed while the red pulley moves. The grey pulleys are about 4 ft apart. When the fine adjust isn't in use the red pulley is allowed all the way to the back of the boom until it butts up to the rear fixed pulley at this point a 1ft tag line is dangling from boom. When the crew decides to take the main trimming for say double trapping he/she grabs the tag line and pulls it 4 ft out to the edge of the boat and the red pulley is now in its intermediate position.

What do you think?

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Nacra 6.0 NA
Ogden Dunes, IN
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Very smart solution. It's hard to if some details may fail, I see a few things to have in mind
- The forces may be very high, be careful at the attachments at the boom.
- If you are using the yellow line from the helm, it seems that the force might tend to pull the boom out of the gooseneck
- A 18:1 system will mean a lot of rope to produce limited effect on the sail, the fine tuning might end up too fine for what you are looking for. Or could be too slow or too short for avoiding a capsize.

About the traveler moving when you pull the mainsheet, I've always had this problem with my N5.5, I did a few things about it:

- As someone already said, I started using a lot more the downhaul to flatten the sail and now play much less with the main.
- If it's blowing hard I prefer to pinch instead of easing the main. In this video it is pretty evident at 1:09, I don't want to scare my daughter. After she fixes the outhaul and goes out on the trap, I never actually took all the wind
https://www.youtube.com/watch?v=Tl9tAkREld0
- I made this invention to be able to lock the traveler in position:



At each side of the rear beam there is an eyestrap in the back, where that red line starts and a block in the front for the same line. I added two blocks at each side of the traveler for the rope and two cleats like the one with the red part (the other one is green and opposite). End result is something that works but that I almost never use. I mostly keep the traveler centered, and if it's blowing to hard, bothering on this littke cleat is not a very good idea. On longer runs I occasionally use it but not very often.

Yes 18:1 might be too much. I'll have to play with it. as for the force on the gooseneck, as long as the trimmer is pulling perpendicular to the boom the net fore/aft force should be zero. the tension should all be between the two grey pulleys. Now if the helmsman is all the way at the back of the boat and pulling onthe fine tune it would yield some force away from the mast. not enough to overcome the force of the 8:1 on the boom. The existing 8:1 would be mounted behind the rear cross bar on the boom like new cats do.

I thought about that double cleating system on the traveler like a keel boat would have. Looks neat in your application. Doesn't that make it non self tacking though? Nice Boat!

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Nacra 6.0 NA
Ogden Dunes, IN
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Talk to texastuma about a cascading system. I run a 10:1 on my square topped prindle 19 and its plenty. The trick is reeving the block and tackle so it doesnt bind.

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Captain Chris Holley
Fulshear, TX
'87 Prindle 19 "¡Hijole!"
'74 sunfish "1fish"
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I thought about that double cleating system on the traveler like a keel boat would have. Looks neat in your application. Doesn't that make it non self tacking though?

The line runs free under the red part of the cleat, when not cleated, and the traveler works the normal way. When you want to fix the traveler you just cleat the line, on the windward cleat close to you. Before or during the tack you uncleat it and then cleat the other side if you want. What defies the solution is that it takes some attention during the tack, which you don't want on rough conditions. Worse if you are already out on the trapeze. It is very nice to have it on low wind conditions with waves, where the traveler is constantly moved by the waves and the sail. Uncommon and not very exciting situation though...

I would make the following improvement (still can):
Move the cleat even closer to the hull and a bit down. You can see in the picture that the line is deviated up a little bit and this may produce unwanted operation of the cleat sometimes.

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Nice Boat!

Thanks! :)

Here's my first attempt, with two cleats at the center of the beam instead of one. This one required to adjust at each tack and it just sucked.

Visible very shortly at 0:29
https://www.youtube.com/watch?v=TgQxIS0TDDM

On a side note, this was a small lake near Santiago in Chile, today it's completely dry, doesn't exist anymore.

Kevin219

Because I'm too cheap to pay $600 for 12:1 main sheet blocks. Consider the pictures above and below. Pretend I add a pulley where the mainsheet currently ties off and go back to boom. That will turn my main sheet from 8:1 to 9:1. Then I take the end of that line and attach it to a pulley. That pulley is in turn its own 2:1 purchase system. Now I will have a 9:1 main sheet as well as a 18:1 Main sheet. (If I want 8:1 and 16:1 i can unthread one of the pulleys on the main blocks.) This will give me an optional fine adjust main that I should be able to trim with one hand.

Here's my favorite part:



In the picture above, the grey pulleys are fixed while the red pulley moves. The grey pulleys are about 4 ft apart. When the fine adjust isn't in use the red pulley is allowed all the way to the back of the boom until it butts up to the rear fixed pulley at this point a 1ft tag line is dangling from boom. When the crew decides to take the main trimming for say double trapping he/she grabs the tag line and pulls it 4 ft out to the edge of the boat and the red pulley is now in its intermediate position.

What do you think?

It does make it easeir to use, but the problem becomes the amount of line you have to pan out in puffs. I run a 12:1 and it is easy to play, but we get puffs from 8 to high teens/low 20s.. so it becomes all in to all out.. I'm running a cascade sheet on a boom: 3:1 to a 4:1. The Tornado sill has a 9:1 and it gets my attention..

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Scott

Prindle Fleet 2
TCDYC

Prindle 18-2 Mod "FrankenKitty"
Tornado Classic "Fast Furniture"
Prindle 19 "Mr. Wiggly"
Nacra 5.8 "De ja vu"
Nacra 5.0
Nacra 5.8
Tornadoes (Reg White)
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