Asym on a Furler

[colemj]

Originally Posted by Curmudgeon

Many thanks, estarzinger, for your detailed and very helpful response.

If you take a look at the CDI furler, as opposed to the Facnor (and Facnor clones), you will see that CDI has an anti-rotation bar on the upper swivel. The Facnor does not appear to have this. See the part labelled "L" and the picture on p. 8 of the manual for CDI's spinnaker furler: http://www.sailcdi.com/sailpdf/Spinn...r%20Manual.pdf BTW I'm not in love with the CDI design, because I can easily imagine the anti-rotation bar fouling some other bit of rigging or poking a hole in a sail. But maybe it works.

I raised the rotation issue because a very experienced sailmaker and a very experienced yacht manager (both in the Newport, RI area) both raised it.

The ability to just set the sail and forget it is important to me. I'm definitely leaning towars a smaller "gennaker" or "UPS" type sail on a removable furler.

For sails to be used on a continuous furler, the luff has to be pulled very tight. When raised, the halyard will only have a few inches free of the sheave it rides on. With a tight luff and a few inches free, there is no way the halyard is going to twist more that a single 90 degrees over the couple inches that are free.

Mark

[colemj]

AH! I just looked at the CDI manual. That furler is a completely different beast designed for furling an unconnected spinnaker without a luff rope. The Facnor is not designed for the same purpose or sail. Technically, if the CDI furler was tensioned properly, I don't see the need for that bar.

Mark

[Bash]

Originally Posted by Curmudgeon

The ability to just set the sail and forget it is important to me. I'm definitely leaning towars a smaller "gennaker" or "UPS" type sail on a removable furler.

That being the case, you might want to look into a North 3G. When I bought mine, I was skeptical about their claim that it's a "set it and forget it" sail, but in reality it requires much less attention than a normal assym.

I've opted to go with a sock rather than a furler because this gives me the ability to sail deeper, especially in lighter air. The downside is that the sock system requires someone to go to the foredeck to set the sail. That said, the sock that North built for the 3G is marvelously easy to use, far better than the ATM system. I can even snuff the chute when it's powered up.

[s/v Jedi]

Originally Posted by Bash

That said, the sock that North built for the 3G is marvelously easy to use, far better than the ATM system. I can even snuff the chute when it's powered up.

So what did they change in the design of the sock? I don't see much potential improvements when I look at my ATN socks and have the feeling I am missing something

ciao!
Nick.

[estarzinger]

Originally Posted by Curmudgeon

you will see that CDI has an anti-rotation bar on the upper swivel.

I see. Interesting. Rather kludgy looking - like they discovered a problem and whacked on a temporary fix.

I have never used the CDI system (or even seen one used). I do have experience with facnor (and karver and Harken zero furlers), and these are general the units I see used on the top offshore race boats. I have not heard of any halyard twisting problems with these - and we certainly have not had any with ours. But if you wanted to absolutely minimize any possibility you could go to a 2:1 halyard as many of the race boats do (not because of twisting but to use smaller halyards, to minimize mast compression, and to get more luff tension). A 2:1 would provide some 'section' to the halyard which would resist twisting.

I raised the rotation issue because a very experienced sailmaker and a very experienced yacht manager (both in the Newport, RI area) both raised it.

Did they raise it related specifically to the CDI system, or related to all rope luff furling systems? Perhaps there is something in the CDI approach that needs it. The other (Facnor) furling systems have been used for going on a decade now and they obviously have not felt any need to add that sort of anti-twist stick to their swivels.

I am just drawing a blank on halyard twisting as an issue.

on socks vs furlers . . . both work pretty well but we find the furlers easier for two reasons. First when there are random squalls around (as on many tropical passages at night) when a squall approaches - with a sock you need to sock and then drop the whole deal on deck lash it down and then unlash and rehoist and unsock when the squalls by - with the fuler you just tightly furl and can leave it up and unfurl when the squall is by, which is quite a bit less work. And second, when the wind speed has snuck up and we have not noticed until too late we have had times when it has been extremely difficult to get the sock down over the chute (even after blowing the tack). Once we just had to let the halyard run and drop the chute in the water and then go over and fish it out. With the furler we always seem to be able to get it rolled up pretty quickly without too much trauma - sometimes the roll is not so neat and we have to straighten it out later.

[Bash]

Originally Posted by s/v Jedi

So what did they change in the design of the sock? I don't see much potential improvements when I look at my ATN socks and have the feeling I am missing something

Better blocks, and a carbon-fiber ring.

[Pyxis156]

We have a Facnor 2500 Asym-FX furler with an Ullman "2A Light Air Running Asymmetrical" (definitely not a Code 0 shape to the asym) and after a fair amount of tweaking with the setup are happy with the result. We ended up with the furling setup for the reasons Evans lists below and for the desire to not have to leave the cockpit to furl. Our earlier experiences with a sock indicated someone having to go forward to sock the spinnaker and a difficulty in getting it down over the spinnaker if the winds pick up. Both are dealt with pretty cleanly with the furler. And Evans comment about the roll not always being so neat is spot on in our experience as well, but it does furl every time without going forward which is a huge plus for our purposes.

One thing I am surprised about is nobody has mentioned is the amount of work furling a spinnaker is. If you think about it, you are furling your biggest but lightest fabric sail around a "stay" that is about 3/4"-1" in diameter and that takes a LOT of wraps! I would be one step from a heart attack by the time I was done cranking the furling line with our winch using a winch handle. Luckily a friend has an electric drill with a chuck that fits the star socket in the top of a winch and we use that as a poor man's electric winch and it has proven extremely effective.

Originally Posted by estarzinger

on socks vs furlers . . . both work pretty well but we find the furlers easier for two reasons. First when there are random squalls around (as on many tropical passages at night) when a squall approaches - with a sock you need to sock and then drop the whole deal on deck lash it down and then unlash and rehoist and unsock when the squalls by - with the fuler you just tightly furl and can leave it up and unfurl when the squall is by, which is quite a bit less work. And second, when the wind speed has snuck up and we have not noticed until too late we have had times when it has been extremely difficult to get the sock down over the chute (even after blowing the tack). Once we just had to let the halyard run and drop the chute in the water and then go over and fish it out. With the furler we always seem to be able to get it rolled up pretty quickly without too much trauma - sometimes the roll is not so neat and we have to straighten it out later.

[muskoka]

Continous line furlers have a swivel shackle at the top, so halyard twist is minimal. We use a Profurl, without any problem. But the key is halyard tension - it's gotta be tight.

The big thing to decide is whether you want a Code 0 (Doyle UPS) or a spinnaker. We use our Code 0 much more than our spinnaker. We leave it furled on the bowsprit and she runs pretty nicely from about 65 to 150 degrees.

If you go with a spinnaker, forget about furling - it'll take forever. Socks are OK, but we find it easier to just spike the tack and letterbox it.

[daddle]

Originally Posted by Pyxis156

One thing I am surprised about is nobody has mentioned is the amount of work furling a spinnaker is. If you think about it, you are furling your biggest but lightest fabric sail around a "stay" that is about 3/4"-1" in diameter and that takes a LOT of wraps!

Not my experience at all. It's effortless with my Harken continuous line furler. Far easier than a headsail furler. Takes 30 seconds for my HUGE spinnakers.

[senormechanico]

Originally Posted by 44'cruisingcat

This does look pretty easy:

With flat water, lots of luff tension and practically NO wind, yes.
I'd like to see a video made with at least ten knots and increasing wind when on a downwind course.

[svloki]

We have 3 downwind sails on board- spectra code zero on a profurl system, asymmetrical in an ATN sock and lastly a triradial symmetrical spinnaker (no sock). By far the best trade wind sail has been the old symmetrical flying with a pole. The 'code is great but in very light going but the laminated construction takes a beating from rolling. The Asym is fine on some angles but wont fly super deep angles. I found the plain old kite much more stable, adaptable to conditions, and still easy to douse behind the main. When the wind comes back up the code goes out. This may be heresy, but I might skip the asym on heavy (slow) cruising monohulls.

[Pyxis156]

Originally Posted by daddle

Not my experience at all. It's effortless with my Harken continuous line furler. Far easier than a headsail furler. Takes 30 seconds for my HUGE spinnakers.

Daddle,

Could you elaborate on how your continuous line furler is setup? Maybe I am doing something wrong?

Thanks

[daddle]

The lower unit clips to the stem and the tack of the sail. The head bearing between the halyard and head. A double guide block clips to the toerail a meter from the stem. The continuous line is run back the deck to a snatch block just aft the cockpit. No slack in the furling line, but not tight either. You must do a perfect splice. It will be a half-strength skinny one. But that doesn't matter because it's a handline.

The unit spins effortlessly even with a moderately loaded sail. It may take 50 turns or more. Haven't counted.

A double luff rope helps. But one sail is without and works just fine. Only moderate luff tension is needed while furling. Without the double luff rope the head will slowly unwind. Which can be a small disaster. So I lower the furled sail immediately.

If your decks have that cluttered garage-sale look you'll have problems.