Beyond that I think wrapping the sheets around the sail like a candy cane from the clew most of the way down, and then pulling the furling line (both parts) tight and cleating it tight against tight sheets will keep the furled sail put. This will offer a lower clew height and allow the user to manipulate the sheet longer before the entire sail is furled away. I think (and I am no sailmaker) a longer leech and shorter luff promotes better furling. We think the ultimate best solution is to have a sail especially cut to accommodate better top down furling. I have to say, I do not know the Bartels or the Magic Furl systems (pictures are welcome, However, all of these systems suffer from a loose furl from where the clew gets wrapped up, on down. We’ve been working a lot on these spinnaker furlers lately and with many different manufacturers. I am considering locking off hte top swivel and effectively making the system into a top down furler but am concerned about the twist in the furling line. This is particularly important to us a s we are a husband and wife team (not so young), who do not want to go on the foredeck when crossing Biscay particularly when there are large swells. The system works fairly well but we have a lot of trouble getting a tight furl which is very important to enabling the sail to stay furled in position when the conditions become unfavourable, without the wind getting into it. This system uses a Bartels furling drum ( made by the German Company). These strings are attached to the luff of the sail. There are 2 strings tied onto the torsion rope at approximately 1 third and 2 thirds up. The system relies on swivels at the top and the bottom of the torsion rope. I cruise extensively on the west coast of France and across the bay of Biscay (300mls) each year. Hi, I have an asymmetric masthead spinnaker fitted to a Magic Furl system from Crusader sails of the UK, on My Beneteau Oceanis 411. Hampidjan, maker of some of the best torsion cables on the market, makes their cable. They have very good reputation, have a very nice looking product, and use the balls along their torsion rope to help alleviate stress on the sail and perhaps alleviate the ‘back twist’ issue. All of these systems are very similar as it’s pretty hard to reinvent the wheel but each offer some unique feature or selling attribute. So let’s take a quick look at the various manufacturer’s and what their doing to address these issues: The systems worth looking at are Ronstan (click link for more info.), Pro Furl, Selden, Karver, Facnor, Bamar, and as of recently Harken joined the line up. ~Lastly, make sure that the person on the furling line never ever lets off of the furling line if it feels tight or bound up.~ So it is a fine line. The next component is to make sure that the sheet trimmer is paying out enough line during the furl, especially during the initial portion of the furl. However, over-tightening can lead to the bearings in the furler trying to bind and thus make furling very difficult. Adding a 2:1 spinnaker halyard or tack line…or both is also a great way to achieve this. This will stiffen the cable and reduce cable torsion, and also provide a better axis for the sail to furl around. One way to alleviate this is to ensure the torsional rope is very tight. The good news if this should happen, it can always be lowered. This will need to be lowered spread out on a lawn and dealt with that way. This can make a partially furled sail unfurl, or even worse, begin to furl the sail in the opposite direction and make for a sail that won’t furl or unfurl any further. Then once the person realizes the sail isn’t furling, stops furling, eases the tight furling line, and all that torsion comes spinning back down the rope and into furling drum. This induces lots of stress on the system and the sail, but also creates a lot torsion loading on the rope itself (hence the rope being the most crucial component). This means that torque has to go somewhere and that is up the torsion rope. This is where the sail has suddenly stopped furling, but the person on the furling line is still furling. That being said, the issue that seems to haunt top down furlers (and it’s always something) is called “back twist”. Lastly and most importantly, it’s very much the users technique. Then it’s also the bearings in the drum, tack swivel and head swivel having a large capacity for high loads. The 1st secret to a good Top-Down Furler is the torsion rope. This system is all about set up and even then, it is not without its problems. Although this system makes it much more viable to fly a spinnaker there is still a learning curve. However, nothing is just push a button and ‘bang’ there’s your spinnaker. Top down furling is the new revolution that makes flying the big sails a much more achievable task.
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