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Alan and Paul's secret weapon for the Everglades Challengec

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Well, it did not make Dawn Patrol any faster, they already had the spinnaker but the top down furler certainly made spinnaker hoisting and dousing quick and easy so that they could use it even on short legs where they might not normally feel that it would be worth the effort or use it in more marginal conditions knowing that they could easily get rid of it.

 

I have been lusting for a top down furler for a long time as I usually sail Carlita solo or with my dog. Mandy does not seem to care about that pretty red, white and blue asymmetric spinnaker. It was the price tag of around $1000.00 that discouraged me. They have been in use for large short handed boats for some time now but it appears that manufacture's cannot be bothered with those of us who sail small boats. 

 

I started to design one for myself. As I delved into how I was going to make double concentric ball races it occurred to me that I could just make a swivel and insert it into Ronstan's bottom up 60 series furler. I showed the drawing to Alan and said that I would make one for him for the EC, he just happened to have an R60 on Mosquito. We ordered up some torlon balls and I got to work on the lathe.

 

What makes the top down furler different is that the furling drum does not connect to the tack of the sail. The drum is connected to a torque line that turns the top swivel so the top of the sail winds up first and starts removing that extra cloth from the middle of the sail before the foot of the sail starts to wind up. . The tack is attached to the second swivel which makes it independent of the furling drum.

 

Bottom up furlers work okay for relatively flat cut sails but top down works better for spinnakers.

 

The first picture shows our shop built swivel waiting for the torlon balls to arrive. I got lucky as we tried a spare length of dacron braid that just happened to be twice the length of the hoist. We tied it as a double line and it seemed to be about right.  The shackle showed that it might foul or at least chafe on the sail as it rotated. I rounded out the shackle hole to reduce chafe and replaced the shackle for multiple wraps with a light lashing and eliminated the problem.

 

Drum furlers won't work because they cannot hold enough line. You need the endless line that just has a single turn around the drum giving unlimited turns. They are also less sensitive to line alignment which allows the drum to out-hauled to the end of the bowsprit or in-hauled as needed.

 

Here is the email that Alan sent the first night of the EC.  spinnaker flying all day furler works like a dream. 14knots recorded. heard a sea pearl capsized have no more details. having fun. Boat feels old hat at this.

swivel.jpg

swivel3.jpg

swivel 5.jpg

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I thought I needed a mizzen staysail but now maybe I need this! 

 

This looks like a lot of bang but also a lot of buck (bow sprit, back stays, etc.).

 

Can you comment on the benefit of one vs the other?

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Hi Matt

 

You are right, it is a lot of stuff.

 

Wind pressure goes up or down by the square with wind speed. For instance if 16 knots of wind is perfect, then you are only getting 1/4 of wind force at 8 knots. If you can add more sail in light air it can add a lot your performance.

 

When the wind gets lighter still, say 4 knots you are only getting 1/16 of the wind force. Sometimes the boat just feels stuck, what is happening is that the sails are stalled and it is hard to feel what is going on. Adding more sail can sometimes get you out of this stalled situation and move the apparent wind forward and get you moving really well. It can sometimes mean the difference between not moving at all to coaching 3- 4 knots out of the boat instead of being stopped.

 

To answer your question, the spinnaker is bigger and has more effect over a staysail. The staysail has less stuff to get and is all inboard. It just depends on what you want to achieve. When the wind is way forward, the spinnaker will give you some lee helm. You can lower the board all of the way which helps. This is not a problem in light air but is can get heavy in strong winds. When this happens you can bear away and solve the problem but if you have to sail that course, then it is time to furl it up.

 

I have never tried to fly both at the same time, feeling that the staysail might rob more from the main and mizzen than it gives and just concentrate on making the spinnaker work as efficiently as I can.

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Graham, would you get the same effect by shackling the tack of the spinnaker or gennaker to a separate point close aft of the R60 (but clear above the furling line) so the torsion line still operates separate from the lower end of the luff, thus avoiding the need for the swivel?

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Interesting solution Graham. I played with making something similar a few years ago, but went with a split ring (instead of captive ball) arrangement. It's funny how we approuch things. I was working through this on my old 35' CCA Lion Class, converted to yawl. I need a better way to hoist, douse and furl the mizzen mule, which was a sail I liked to use fairly frequently. I had a couple of different staysails and wanted a relatively cheap way to have everything attached, so I could hoist from a cockpit locker, dog down and runout pretty quickly. 

 

The drums I found commercially were either too big, quite costly or had too much diameter to be effective on the smaller sails I was using. Initially, I tried what I saw in a Karver bottoms up setup, but didn't like the lack of furling line exit adjustment. Eventually I made a drum that worked pretty well, once I got the friction thing worked out and a Ronstan 60 series swivel, for their code zero/drifter setup.

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Drew,

I had the same question. Unfortunately that would only work to furl the sail in about half way and then it would bind up. Once the top half of the sail starts to wind onto the torsion line then the whole thing goes and the tack starts wrapping up as well. We found the best was to just keep winding and all the spinnaker sheets were taken up (wrapped around the sail) and all out of the way. 

 

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That makes good sense Alan. Your video is very helpful. It looks like it could be safely handled even single-handed so long as no spinnaker pole is being used. Thanks.

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We found the sail very easy to handle. For single handing the continuous line could be run all the way to the stern of the boat even. The top swivel we were using was a bit sticky and the whole arrangement meant that in lighter winds we had to positively "unfurl" the sail when we wanted it out. It would unfurl about half way but then to get the last twists out of the top we would have to pull the furling line the other way to take some torsion out of the taught line. 

 

The best part about it was that it furls with no hassle in strong winds. Because of this we used the spinnaker much more than any other year because it was so accessible and I know it made us faster. With this asymmetrical spinnaker we can sail about 30 deg. off the wind and gybe downwind when downwind is our goal. Deeper than that and the sail doesn't get enough clear air. We carried the sail up to about 15 knots and then switched to wing and wing. If I had to guess, in 15 knots of breeze we maybe gain about 1/2 a knot of vmg by gybing downwind with the spinnaker versus sailing dead down wind wing and wing. In 10 knots of wind it might be closer to a knot faster vmg with the spinnaker. 

 

We left the sail up, furled almost the entire time in the EC this year only taking it down when we had to paddle hard into the wind to get out of a narrow pass at the checkpoint and didn't want the extra windage. 

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Very cool Graham! Looks like your swivel works incredibly well. I've lately been installing hardware to the masts for Deluge. Could you send me a dwg or description of hardware and location for the running back stay and spinnaker? The drawings I've got only include the halyard block and cleat for the staysail.

Thanks!

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Fred,

 

I will work on it. I am also updating the dodger plans for you.

 

I have been working on being able to produce the adapter swivel at an affordable price. I am planning on being able to CNC cut the swivel body from UHMW plastic. I have built a cutter for machining the races and will make up a new swivel and give it a good testing.

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