Hey folks,
I'm from Germany. Sailing a 1994 Nacra 5.0 which is a super fun boat.
When its blowing harder I would love to get the main more flat. My mast points nearly 90° to the hulls.
The 500 have a rotation device but unfortunatly the manual says nothing about how its made.
Have someone pics of a 500 with rotation or a retrofitted 5.0?
Also interesting is a boom. The main is very close to the tramp so for a really good way the do it, the sail foot must be shorter. Or with a bend boom like the decksweaper F18's.
Thanks, Hannes
retrofit mast rotation and boom Nacra 5.0/500
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Posted: Aug 14, 2020 - 08:43 AM
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Posted: Aug 14, 2020 - 10:43 AM
If you are evaluating adding a boom, that decision comes first because the mechanism is opposite. With a boom the outhaul tension works against the mast producing rotation, the mast rotation device restricts the rotation produced by the boom. The rotation arm points back and restricts the rotation.
Without boom the rotation arm points forward and you pull it from the windward side against the front beam (typically) to increase the rotation, normally downwind, that system cannot restrict rotation.
I'm not sure that mast rotation is your first alternative to flatten the sail, outhaul and downhaul come firts. You don't have an outhaul but you should have grommets to attach the mainsheet hook. -
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Posted: Aug 14, 2020 - 10:50 AM
mast rotation actually flattens the sail, doesn't it? Rotated mast will bend more and therefore flatten the sail. -
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Posted: Aug 14, 2020 - 11:03 AM
Downwind isn't my problem here, its more upwind. As I said, the mast nearly points 90° to the hulls. This makes the sail deep and give much of profile. Most books and text i have read till now says the rotator should point towards rear beam end (lee) when it comes to upwind. And towards front of daggerboard or stays when sailing downwind.
Downhaul clearly comes first. But the mast rotates it self due to the tension in the sail and the cut.
Sail is quite new, and comes from probably the best nacra sailmaker around here, shouldn't be the problem.
My 5.0 hasn't got a boom. The 500's also hasn't as long as i know. -
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Posted: Aug 14, 2020 - 11:21 AM
That is with a boom
In this picture you can see one case without boom, here it seems to go under the tramp but it can also be cleated at the beam, in that case there is an arm wider at the tip that works better, with two attachment points rather than one, so you can overrotate (not really but works better when you want to produce 90° rotation) (I know it's not what you want, just explainng what it's used.
More interesting on the picture is the traveler clew, which I believe migh be a good option for you, instead of a boom. I have that on my 5.5 and like it very much. Still, a 90° rotation upwind is not right, that deserves some root cause analysis before fixing the problem, not sure why that might be happenin.
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Posted: Aug 14, 2020 - 11:24 AM
The Clew plate on the sail is there to flatten sail. Attach main block further aft to flatten and further forward to put more belly in the sail. Down Haul will do the rest. I wouldn't mess with the natural operation of a boom less rig. I also use a roller furling jib to depower boat in a heavy blow and sail main only.
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Pete
2001 NACRA 450 SOLD
2000 NACRA 500 TOTAL LOSS
2004 NACRA INTER 20 SOLD
2016 NACRA 500 Sport
DeLand, FL
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Posted: Aug 14, 2020 - 11:30 AM
I'd say the other way around? -
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Posted: Aug 14, 2020 - 04:05 PM
@saltlife77
I'd also say that cleating in forward will flatten the main and other way around.
Sailing without the jib in heavier conditions is quite difficult when it comes to tacking. Do you have any tips? Normaly I use the jib backwindig in tack.
@Andinista:
thanks for the article! Great to read and very inspiring. The sheeting in hardly section makes me laughing.
But I still didn't get 100percent of the message with the mast bend, rotation and shroud tension.
To depower the main above 14kts I use a spreader rake of about 45mm (should be about 1,8") while in softer conditions 25mm (1") doing just fine. In both situations a 90° rotation is normal.
Probably I have an issue with the shroud tension. My shrouds are as tight as I get them with the standart adjusters (holes are far from another due to the "one hole line")
To set up shroud tension i ask the heaviest guy in range for help (pulling a trapeze line as hard as he could while i set the shroud)
Maybe this isn't enough. Are there any tricks to achieve more tension (using mainsheet or something?)
I didn't own a tension gauge cause they are that pricy.
Edited by hannes-neo on Aug 14, 2020 - 04:12 PM. -
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Posted: Aug 14, 2020 - 07:12 PM
That should be enough, set one hole above and you should notice that it rotates easier but with shroud tension it’s not like you will limit rotation completely. If you feel you may go a bit further it’s not a problem to set one adjuster one hole lower than the other. Or for testing with rotation at least, but under human weight limits It seems reasonable, you don’t want to crank your shrouds like crazy.
Edited by Andinista on Aug 14, 2020 - 09:57 PM. -
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Posted: Aug 15, 2020 - 05:36 AM
Maybe have the heavy guy hang on the trap rather than pull it.
About tacking, stupid as it may sound it’s very common to forget about the tiller in critical instants, like when you are moving to the other side or when it’s time to revert the steering and complete the turn backwards. I never sail without jib though but I guess that is still a point. Also start tacking close hauled. -
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Posted: Aug 15, 2020 - 07:19 AM
I did it the most powerfull way. Proper tension measurements without expensive tools would be nice anyway.
Tacking is mostly correct performed I think. But I definitly i forgot to steer correct in the first days (long time ago).
I wonder how saltlife77 is doing his tacks. Would be nice to read about.
So does no one retrofitted mast rotation on a 5.0/500? -
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Posted: Aug 15, 2020 - 08:17 AM
That is backwards. Hooking to the forward holes allows more mainsheet tension, which flattens the sail.
I installed mast rotation on an N5.7, but removed it, just wasn’t worth it.
http:// https://www.thebe…4c71c44ce2c5b05ea8a4343a
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Posted: Aug 15, 2020 - 05:23 PM
I didn't feel I needed one when I had a N5.0. Now my N5.5 has one and I like it very much to lock rotation completely (cleat both sides) when trailering or the very few times that I’m out with waves and little wind. But for sailing I don’t really use it. The few times I did it, too often i forgot about it before tacking. -
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Posted: Aug 16, 2020 - 12:05 PM
Fixed the link, for some reason when using an ipad the links dont work. The lines in this photo are wrong, each side should dead end on the beam eye just inside the cleat on the beam. You run the line from dead end to rotator-back to cleat- around mast- through opposite cleat- to rotator - back to dead end. This gives a 2:1 for positioning the rotator, & it does require some force with higher wind loads.
As Adinista said, I didn't use it much, especially solo.IT was handy when in choppy seas & light wind. The mast would bang around, shaking what little wind ther was out of the sail, & generally annoying the hell out me.
Edited by Edchris177 on Aug 16, 2020 - 12:09 PM.
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Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
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Posted: Aug 19, 2020 - 07:28 PM
This may be the best and simplest forced mast rotation I have ever seen. This would give you what you want with a soft rig (not pre-bend) mast in a big blow on a broad reach. Or travel in and employ a boat load of leech twist.
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Posted: Aug 20, 2020 - 03:04 PM
LOL...yes I did get that backwards didn't I...That's what I get for chiming in while I am at work LOL.
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Pete
2001 NACRA 450 SOLD
2000 NACRA 500 TOTAL LOSS
2004 NACRA INTER 20 SOLD
2016 NACRA 500 Sport
DeLand, FL
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Posted: Aug 20, 2020 - 04:02 PM
What I said is wrong, you can restrict rotation with this system on a boomless boat, just pull on the other side. It's just unusual I think. -
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Posted: Aug 22, 2020 - 11:04 AM
Here is a video of my buddy's g-cat with positive mast rotation - lots of footage of him setting, using it, how it's reeved, etc (he runs the lines back to deck cleats near the skipper)
lots of good footage of him using it - then we pull out his spin to "dry it off" around 1:15
then it gets "un dry" :)
https://www.youtube.com/watch?v=o-ajtJfs-Sc -
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Posted: Aug 22, 2020 - 11:07 AM
Here is a video of my buddy's g-cat with positive mast rotation - lots of footage of him setting, using it, how it's reeved, etc (he runs the lines back to deck cleats near the skipper)
lots of good footage of him using it - then we pull out his spin to "dry it off" around 1:15
then it gets "un dry" :)
https://www.youtube.com/watch?v=o-ajtJfs-Sc -
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Posted: Aug 23, 2020 - 07:19 AM
Thanks for all the tips and inspiration.
I'll build some kind of rotation device in winter 2020 and will let you know about it.
If there is any 500 sailor with nice pics of his rotation or boom setup it would be nice to read about.
