Tips for top down furler?

[flightlead404]

I just purchased an asymmetric spinnaker and topdown furler from a list member and got to play with it a bit yesterday.

We are struggling to get a good furl and looking for suggestions, tips, and tricks.

Mostly we get too tight a wrap around the bottom, with a big loose area in the middle that in a few minutes works its way out and starts to wrap the jib or just flog around.

Any suggestions viz the furler torque cable tension, sheet handling, and so on?

 

[jssailem]

I have little experience with the Top Down furler. I understand rig tension is an important issue as you need the tension to help the furler to turn the complete length. You also need the furler bearings to be clean and moving if the rig is to turn properly.
Some sails will be too full to work properly.

As you describe it is easy to wrap the base and the full middle or top are too slow. Try adjusting your tack down and doing the wrap in the shadow of the Mainsail..

Check out the Youtube videos by Harken on the use of their TopDown Torsion Furler.

 

[DayDreamer41]

Key to the operation of the TD furler is shock cord tension, as tight as you can get it.
Why can't you just barber pole the sheet over the sail to restrict its movement / ballooning / flogging?

 

[flightlead404]

Key to the operation of the TD furler is shock cord tension, as tight as you can get it.
Why can't you just barber pole the sheet over the sail to restrict its movement / ballooning / flogging?

I’ve tried with various tension. I can crank it down so hard the forestay is loose still get the big baggy section in the middle.

sheet wraps don’t help. The clew is high and the sheets fall down but regardless it’s the top 1/3 that is an issue

will take pics this weekend if I get it out

 

[DayDreamer41]

Interesting, when we furl ours the clew ends up about midpoint of the rolled sail once barber poled the sail is quite secure, on occasion if there was not enough tension put on the sheet the sail does end up with a section that bags at which point we will unfurl and refurl the sail solving the issue. Perhaps you are not putting enough tension on the sheet when you furl the sail.

 

[flightlead404]

Perhaps you are not putting enough tension on the sheet when you furl the sail.

Could be, I''m going to experiment with that and the sail in various stages of stalled and deflated

 

[Hayden Watson]

I am curious about how the bottom is being wrapped tight and not the top. With a "top down" furler, the bottom should not rotate at all so it will be the last thing to roll up. Do you instead have a code-0 furler that does not have a freely spinning tack bearing? They look about the same except that the on the TD the tack does not rotate with the torsion line and on the code-O the tack rotates with every turn of the torsion line.

 

[flightlead404]

I am curious about how the bottom is being wrapped tight and not the top. With a "top down" furler, the bottom should not rotate at all so it will be the last thing to roll up. Do you instead have a code-0 furler that does not have a freely spinning tack bearing? They look about the same except that the on the TD the tack does not rotate with the torsion line and on the code-O the tack rotates with every turn of the torsion line.

I don't understand what you're saying. The tack and the head components of the furler allow the torsion cable between them to rotate at both ends. I cannot see how it would possibly work if only one end rotated, you'd never get more than a couple of turns on. The head fitting has an anti-rotation pin so the rotation can't be transferred to the halyard. The furling "drum" (really a sheave of sorts since its a continuous loop) is at the bottom which obviously rotates with the torsion cable. Its fixed to the anchor roller.

The bottom of my sail most definitely is tight and the top loose and baggy.

 

[Hayden Watson]

I don't understand what you're saying. The tack and the head components of the furler allow the torsion cable between them to rotate at both ends. I cannot see how it would possibly work if only one end rotated, you'd never get more than a couple of turns on. The head fitting has an anti-rotation pin so the rotation can't be transferred to the halyard. The furling "drum" (really a sheave of sorts since its a continuous loop) is at the bottom which obviously rotates with the torsion cable. Its fixed to the anchor roller.

The bottom of my sail most definitely is tight and the top loose and baggy.

It sounds like yours is a code-0 furler based on what you say. The top down is just that. It wraps the top and not the bottom. This way the very full A-sail will roll tightly at the top and slowly roll downward until the bottom is the last thing to roll up. Beginning about 1:37 you can see the torsion line spinning but the tack not wrapping around it. The torsion line spins full height and wraps the head of the sail around it. The wrap continues from the top downward to about the mid-height before any of the bottom is started to wrap. To work best, you will need to keep some tension on the sheet so that the foot is held away from the torsion line so that it does not begin wrapping too soon.

 

[Hayden Watson]

Here is another video that shows it better

 

[flightlead404]

So you flew out t again this weekend. It appears to wind up from the bottom. It’s like winding a spring, it wants to bounce back and unwind. It’s like the cable is not rotating in the fitting at the head so the cable is storing all the tension.

 

[Hayden Watson]

So you flew out t again this weekend. It appears to wind up from the bottom. It’s like winding a spring, it wants to bounce back and unwind. It’s like the cable is not rotating in the fitting at the head so the cable is storing all the tension.

Do you have any photos of the furler? What brand is it? One thing to remember is that the torsion cable needs to be as tight as possible in order to to turn the top. When it is loose, it will twist like any other rope. When it is pulled tight, it does not twist so that if you turn the bottom one turn, the top also makes one turn.

 

[DayDreamer41]

The tack of the sail should be connected the the drum (spindle) at the bottom, ours is connected with a dynema line, the top swivel is 2 sections, 1 fixed 1 rotating, 1 connected to the halyard the rotating (lower) section to the head of the sail and to the shock cord. When the drum at the bottom is rotated it rotates the upper swivel connected to the head of the sail thus allowing the head of the sail to furl while allowing the foot of the sail to furl in last. If your TD furling system is not doing that I would look at the top swivel does it rotate freely?

 

[flightlead404]

Do you have any photos of the furler? What brand is it? One thing to remember is that the torsion cable needs to be as tight as possible in order to to turn the top. When it is loose, it will twist like any other rope. When it is pulled tight, it does not twist so that if you turn the bottom one turn, the top also makes one turn.

I purchased it used from a forum member, it is described as "CDI Code Zero with torsion cable with upper swivel and lower furler". I think its a first gen furler of this type, it does have some design deficiencies.

I found a manual for it and in reading it is says it should not need more than 150lbs of force, I may be cranking the halyard down way too hard! I will try it again with different amounts of force.

The tack of the sail should be connected the the drum (spindle) at the bottom, ours is connected with a dynema line, the top swivel is 2 sections, 1 fixed 1 rotating, 1 connected to the halyard the rotating (lower) section to the head of the sail and to the shock cord. When the drum at the bottom is rotated it rotates the upper swivel connected to the head of the sail thus allowing the head of the sail to furl while allowing the foot of the sail to furl in last. If your TD furling system is not doing that I would look at the top swivel does it rotate freely?

Yes its fixed like that and its supposed to work like that. Next time I won't be singlehanding and will have someone watch the top swivel with the binoculars but it appears the top is not rotating.

More experimentation to come.

 

[Hayden Watson]

I cannot find any documentation on the CDI code-O furler, but is does not sound like a top-down furler by your description. Here is a good graphic that shows the differences between a code-o (or standard) furler and a top-down furler. The key difference is that on a top-down, the tack of the sail does not rotate with the drum. The tack is attached to a swivel that allows the torsion line to spin but not wrap the sail around the line at the bottom.
If you turn the drum one turn and the bottom of the sail has rolled once around the line it is not a top-down.

 

[Hayden Watson]

I purchased it used from a forum member, it is described as "CDI Code Zero with torsion cable with upper swivel and lower furler". I think its a first gen furler of this type, it does have some design deficiencies.

I found a manual for it and in reading it is says it should not need more than 150lbs of force, I may be cranking the halyard down way too hard! I will try it again with different amounts of force.



Yes its fixed like that and its supposed to work like that. Next time I won't be singlehanding and will have someone watch the top swivel with the binoculars but it appears the top is not rotating.

More experimentation to come.

If the top is not rotating, you could not furl in more than just a little way. without the top rotating, all of the turns you put into the bottom would go into the halyard and it would tie up into a knot. I think your problem is at the bottom of the sail in that it IS rotating.

 

[flightlead404]

I cannot find any documentation on the CDI code-O furler, but is does not sound like a top-down furler by your description. Here is a good graphic that shows the differences between a code-o (or standard) furler and a top-down furler. The key difference is that on a top-down, the tack of the sail does not rotate with the drum. The tack is attached to a swivel that allows the torsion line to spin but not wrap the sail around the line at the bottom.
If you turn the drum one turn and the bottom of the sail has rolled once around the line it is not a top-down.

ah excellent, I will review my pics, but probably need to go back to the boat to verify.