Asym Top down furler

[Hunter216]

I ordered a Ronstan RS006400R (combo kit of drum, top swivel and continuous line) unit today as I feel it has better price/performance than the Harken 1134 Line-Drive & it's associated 1878 top swivel.

The Ronstan info can be found here:

Coming Soon – Ronstan Sailboat Hardware News

www.ronstan.com

More detailed info in the attached pdf

The Harken info is included in the attached PDF. I prepped the info and sent it to Harken for their input.

 

[Hunter216]

Info regarding top down furlers and line drive furlers applicable to the Hunter 216

 

[Hunter216]

Did a little mock up in the yard. Just hand rolled the sail onto a taught rope. No swivels so was fighting the twist in the rope but I was curious if the “stiffness” at the head and tack of the sail due to multiple layers of cloth and stitching would cause trouble. It looks like the furl will be quite tight if the sail is tensioned on the way in.

 

[Hunter216]

The Ronstan line-drive furler arrived and I’ve been busy sorting it out.

I initially tried to rig it with a synthetic rope stay and found that although the bottom drum turned the top swivel didn’t so very tight wrap at the tack end and floppy at the head. At one time I even had a nasty back winding problem to sort out!

I realized that the rope was absorbing a lot of the twist and went to a 1x19 stay wire (inner core wound opposite of outer) that resisted the induced bottom torsion which transmitted the force to the top swivel and ended up with a reasonably consistent furl.

Decided to go sailing to see how it actually worked on the water. Lots of initial thrash at the marina trying to rig everything for the first time but got underway upwind with the sail ready to deploy. No noticeable reduction in upwind efficiency which was a concern.

Deployed and furled the sail repeatedly on both downwind tacks just to be sure, has me convinced that this is a big improvement over a spinnaker sock and the line-drive furler is sufficient to handle the size of the standard asym for the 216.

Deployed

Furled.The balloon in the centre deflated in about a minute. I probably wound it in a little too quickly and captured some air. Technique will likely reduce or eliminate this but it’s not a big problem as once it deflates naturally I’m back to a tight furl.

 

[Hunter216]

The logic of why I chose to try the Ronstan product below.

Although I really like Harken's product the Ronstan equivalent line-drive furler was less $ and has a higher rating as to MWL. The cost differential would be greater if I could have sourced one in Canada and eliminated or reduced the tax-duty charge.

As you can see the Harken Reflex is 4 times the cost and would have been overkill for the size of sail I have. That being said I would give their solution to top down furling a very high rating as they seemed to have waited until everyone else worked most of the bugs out and then proceed to design a system to eliminate or at least reduce those.

 

[jssailem]

Nice write up @Hunter216. This information is transferable to other boats and owners looking for a furler solution. Very helpful.

 

[DArcy]

I agree, great write up. I would just mention that you added tax and duty on the Ronstan but the Harken would still have 13% tax to be an apples to apples comparison.
It looks like you have found a great solution.

 

[Hunter216]

Thanks.
Although I’ve only sailed it once I’m amazed at how easy the spin furler makes handling “the big floppy beast”. The furious thrashing that naturally occurs with a spinnaker I think deters a lot of people and their crew from using this type of sail more often. Trying to yank a sock down over an inflated spin takes a lot of effort sometimes if your timing is a bit off. The furler I feel is familiar territory and makes the task less “intimidating”.

 

[jssailem]

I would agree. One of the issues regarding thrashing sails is the hard ware used to connect lines to the sails. Usually a snap shackle. This risk can be mitigated through the use of good soft shackles. With strong soft shackles costing less than $3 and a little seamanship skill (easily learned) you can protect your boat and crew.

 

[Hunter216]

I would agree. One of the issues regarding thrashing sails is the hard ware used to connect lines to the sails. Usually a snap shackle. This risk can be mitigated through the use of good soft shackles. With strong soft shackles costing less than $3 and a little seamanship skill (easily learned) you can protect your boat and crew.

I’ve removed any metal from my asym rig. I tied a short length of line to the clew cringe and put a crown knot on its bitter hend. I spliced loops onto the end of my sheets and cow hitch the loops over the short line at the clew. Easy to get on and off and no getting punched in the face with a snap shackle!

 

[DrJudyB]

Just for clarity’s sake... the Ronstan Series 60 is not a top down furler. I would not recommend it for furling asymmetrical spinnakers that meet the rating rules doe asymmetric spinnaker (or nearly do, as some cruising asymm do)cut for angles deeper than 90 degrees apparent, because they have a moderately rounded luff, a rounded leech and a significant half girth.

The Series 60 is a great little fry flying furler for code zeros which have an almost straight luff, or with with just a slight positive curve in the luff. It’s also great for staysails and screechers, which have hollow luffs and hollow leeches and are are shaped more liike genoas than spinnakers.
Top down furlers have a swivel where the tack of the asymm attaches to the lower unit. On a top down furler, the torque line and top swivel turn when you pull to furling line, but the bottom of the sail doesn’t wrap until the last moment.

The smallest top down furler that Ronstan offers is the Series 80. You can order the basic standard version for a straight luff sail for sailing AWA <90 (approx) degrees or the “top down” version which has a tack swivel for lashing an asymm spinnaker with a curved luff and a full mid girth, for sailing AWA >90 degrees (approx).

Judy B
Reitired sailmaker
Authorized distributor for Ronstan, Harken, Selden, Spinex/Facnor brands of top down and free flying , continuous line furlers

 

[Hunter216]

Just for clarity’s sake... the Ronstan Series 60 is not a top down furler. I would not recommend it for furling asymmetrical spinnakers that meet the rating rules doe asymmetric spinnaker (or nearly do, as some cruising asymm do)cut for angles deeper than 90 degrees apparent, because they have a moderately rounded luff, a rounded leech and a significant half girth.

The Series 60 is a great little fry flying furler for code zeros which have an almost straight luff, or with with just a slight positive curve in the luff. It’s also great for staysails and screechers, which have hollow luffs and hollow leeches and are are shaped more liike genoas than spinnakers.

Top down furlers have a swivel where the tack of the asymm attaches to the lower unit. On a top down furler, the torque line and top swivel turn when you pull to furling line, but the bottom of the sail doesn’t wrap until the last moment.

Judy B
Reitired sailmaker
Authorized distributor for Ronstan, Harken, Selden, facnor, etc

All very valid points and I likely misused the term top down furler in my journey to a solution so apologize if I created any confusion.

I appreciate that I was/am pushing the limits of what the Series 60 will do but for my specific use, small asym ( <300sq ft) used in non-race and <10knots it seems to work. If $ was no object I would have loved the Harken Reflex 1

Your explanation of the “roundness” in the centre of the sail is likely what caused the balloon I mention so that takes the mystery out of that. These are the measurements of the sail I’m using.

 

[DrJudyB]

i hope it all works out for you. Please use it with caution, because the system you put together is going to be prone to back twisting ( wraps in two different directions). It may not not furl at all if you get caught in more wind than you expected. In the event of unexpected windsthat middle bubble may prevent you from furling A wire is not the ideal choice for a torsion cable and may unlay itself over time or in a big blow.

Be sure to rig it so you can depower it in a pinch if it won’t furl, by easing the sheet, then detaching the lower unit from the sprit, grabbing the foot of the sail or what ever yu can get your hands on , and then releasing the halyard to lower the whole things onto the foredeck or into the cockpit.

Judy B

 

[Hunter216]

I

i hope it all works out for you. Please use it with caution, because the system you put together is going to be prone to back twisting ( wraps in two different directions). It may not not furl at all if you get caught in more wind than you expected. In the event of unexpected windsthat middle bubble may prevent you from furling A wire is not the ideal choice for a torsion cable and may unlay itself over time or in a big blow.

Be sure to rig it so you can depower it in a pinch if it won’t furl, by easing the sheet, then detaching the lower unit from the sprit, grabbing the foot of the sail or what ever yu can get your hands on , and then releasing the halyard to lower the whole things onto the foredeck or into the cockpit.

Judy B

Again thanks for the words of caution and for the emergency dousing procedure. Something I will work out and practice BEFORE I need it so that I can explain to visitors.

During my research it became apparent that the potential for back twisting is present in all of the systems. The two primary factors that seem to cause this problem are the “skill” of how the product is used and the “quality” of the torsion cable.

Part of the skill is the sailor(s) risk assessment of when to not use the sail by ignoring Mother Nature (some people like to really push this).

The torsion cables have improved dramatically since inception; however some of the systems I researched don’t come with a cable creating a situation where the purchaser might try to save $ and end up buying older tech cable thinking that cable is just cable.

 

[DrJudyB]

The best two cables available today are from Harken and Hampidjian. If your free flying furler has either one, and you control the furling properly on the way out as well as the way in, the chances of back wrapping are really small, even in high winds.

Harken’s Reflex Cable is torsionally the stiffest, but can not handle large axial loads such as those generated by a Code zero or screecher without a supplementary cable. It’s better than the competitors at transmitting torque without needing to be winched very tight. It’s ideal for top down furling of Asymm’s with big half widths and curved luffs, but, as I said before, requires an additional line sewn into the luff if you want to pull the luff tight, as you must when the AWA is less than 90, such as on a straight luffed code zero or screecher.

The Hampidjian Dynice furling cable is almost as torsionally stiff as the Harken Reflex cable, but it must be tensioned more before furling. It’s also stronger in axial strain, so you don’t need an additional cable sewn into the luff for a code zero. All the top name brands other than Harken recommend hampidjian.

For example both Colligo and Selden resell Hampidjian anti torque furling cable with their furlers, and both brands curls dependably with proper technique.

An anti torsion rope that twists easily makes it hard to control dousing the sail without back wrap. The cable will store up twists in the middle long before the top starts to turn. As it gets windier, it takes more energy and work in a crummy cable before the cable starts to furl the sail, and it is very likely to twist back so that half the sail wraps the opposite direction as the other half. When furling the sail, don’t pull the sheets tight if there’s any wind, that will Likely cause backwrapping if you let go of the furling line for even a split second

When deploying the sail, Actively control the furling line for the first third or half of the unwrapping process. Don’t pull on the sheets and let the furling line run free (like you probably do with a Genoa furler). That frequently causes a back wrap! Instead, use the furling line to unroll the snits unfurled at least half way.

Also, for reliable top down furling, the luff can’t exceed the available sail space on the furler by more than 4 or 5 percent, and preferable less.

In conclusion, I’d say that free flying furlers work very, very reliably in a wide range of conditions when you combine the right set of components with a properly matched asymm or code zero or screecher, and you control the furling in and out properly.

 

[Hunter216]

The best two cables available today are from Harken and Hampidjian. If your free flying furler has either one, and you control the furling properly on the way out as well as the way in, the chances of back wrapping are really small, even in high winds.

Harken’s Reflex Cable is torsionally the stiffest, but can not handle large axial loads such as those generated by a Code zero or screecher without a supplementary cable. It’s better than the competitors at transmitting torque without needing to be winched very tight. It’s ideal for top down furling of Asymm’s with big half widths and curved luffs, but, as I said before, requires an additional line sewn into the luff if you want to pull the luff tight, as you must when the AWA is less than 90, such as on a straight luffed code zero or screecher.

The Hampidjian Dynice furling cable is almost as torsionally stiff as the Harken Reflex cable, but it must be tensioned more before furling. It’s also stronger in axial strain, so you don’t need an additional cable sewn into the luff for a code zero. All the top name beands other than Harken recommend Hampidjian

The only other competitor that seems to try to differentiate themselves via the torsion cable is Profurl with their ball shaped rollers. I am curious as to your opinion of their system?

 

[DrJudyB]

The only other competitor that seems to try to differentiate themselves via the torsion cable is Profurl with their ball shaped rollers. I am curious as to your opinion of their system?

I can’t comment on Profurl cable with balls, because I have never sold any or used it myself.

I have personally used and sold only Hampidjian and Harken cables exclusively for the past 8 or 10 years, with 99% or better customer satisfaction. In earlier years, we used other manufacturers cables, but the simply weren’t as reliable,

I’ve sold hundreds of Asymm’s, code zeros with and without free flying furlers, from Selden, Ronstan and Harken uand had only one customer in the past 10 years who absolutely never learned out how to operate the furler properly.

Judy B
Retired Sailmaker

 

[Hunter216]

When deploying the sail, Actively control the furling line for the first third or half of the unwrapping process. Don’t pull on the sheets and let the furling line run free (like you probably do with a Genoa furler). That frequently causes a back wrap! Instead, use the furling line to unroll the snits unfurled at least half way.

I found this video from Harken during my research that visually illustrates your point. Also a technique to undo the back wrap if you do get one.

 

[DrJudyB]

I found this video from Harken during my research that visually illustrates your point. Also a technique to undo the back wrap if you do get one.

That technique demonstrated by Harkenworks when the backwrap occurs during deployment, but not when the backwrap happens during dousing. When you get a backwrap during dousing, it doesn’t help. When the cable spins backwards during dousing, It’s usually wrapped against itself so tightly that you’ll probably need to untangle it off the boat, tied between two tree or poles.

I’ve made both kinds of mistakes and sorted out the mess afterwards.

So that during furling, you don’t want to put much drag on the sheets until After the sail is wrapped all the way to the clew. It’s okay if the wrapped sail is a little bit loose.

IMO, It’s a good idea to drop the Furled asymm before sailing upwind if you want good upwind performance, especially in light wind. The furled spinnaker causes a lot of turbulence in front of the jib. It will cost you in terms of how high and fast you can point. It will hurt your reaching performance too, but probably not as critically as pointing.

 

[Hunter216]

Yes I’ve had a few “kite snarls” myself using a sock where the air gets a little blue with >|*~*}*}€}* and I dump the whole mess in the darkest corner of the boat I can find to punish it for wrecking my day!!!

The alternative to flying a big headsail and it’s inherent risks is a boring slog downwind or turning the noisemaker on. Neither of which are my idea of fun on the water.

Socks took a lot of the “trouble” away and I think the furlers are just the next step in the evolution.

Thanks again for all the experienced insights.