The Lunacy Report
- Category: The Lunacy Report
- Created: Thursday, 02 June 2011 15:34
- Written by Charles Doane
One huge last-minute addition to Lunacy's pre-launch punch list this year has been replacing the headsail furler. Near the end of last season I noticed that her old Profurl unit, which probably dates back to the early 1990s, was getting increasingly difficult to use. When rotating the drum, the action was stiff and felt very rough, as though the bearings inside the unit had all gone "square." I had assumed this was reparable. But when Lunacy's rig came out of storage earlier this spring, I asked the guys at Maine Yacht Center to check into it, and they found the furler is in fact so antique that Profurl longer makes parts for it.
So I gave my old friend Scott Alexander at Selden Mast a call, and he hooked me up with a new Furlex 300S furler. Being the fine fellow he is, he also came up to Portland last week and helped me put it on.
The first thing we did was assemble the new furling drum and schlep it up on to Lunacy's deck so I could see how high off the deck I wanted it to ride once the rig is reinstalled. The old Profurl unit, as you can see, was mounted atop some long tangs and rode high off the deck, primarily so it wouldn't get banged up by the anchor as it came aboard. Thanks to Lunacy's new bowsprit, which will carry the anchor further forward and more outboard, this is no longer an issue, but I still wanted the new furling drum to ride fairly high off the deck. In the end I decided I should add one extension link between the Furlex furler and the toggle that would affix the headstay and furler to Lunacy's headstay chainplate. We also deduced we needed to keep the old toggle, which just fits on Lunacy's over-sized headstay chainplate, and could not use a standard Selden toggle.
Next we had to figure out the length of the new forestay. To do this we first measured the length of the old forestay, which, you will note, does not have a turnbuckle or rigging screw on it. Once we had this number, 17.090 meters, we entered it into the table in Selden's well-organized installation booklet. From it we then subtracted the lengths of the various bits of hardware we'd be installing at the end of the new stay that were not needed on the old stay. These included a lower wire terminal with rigging screw (235 mm); the extension link I wanted to add (130 mm); plus the difference (or "delta" as Scott insisted on calling it) between the length of a standard Selden toggle and the longer existing toggle (20 mm). In the end, we determined the new forestay would be 16.705 meters long.
Having derived this number, we next needed to calculate the length of the furler luff extrusion that would be fitted over the wire forestay. To do this, we subtracted a fixed number, 1280 mm (the combined length of the distance from the base of furling drum up to the luff feeder on the extrusion plus the distance from the upper swage-fitting eye to the top of the extrusion), from the forestay length. We thus learned the total length of the luff extrusion should be 15.425 meters.
Selden's luff extrusion segments come in lengths of 2400 mm. To make up a total length of 15.425 meters, we therefore needed 6 full-length segments (6 x 2400 = 14.400), plus one extra one on top cut to a length of 1025 mm (14400 + 1025 = 15425).
Having double-checked all these numbers, we then got out a hacksaw and started cutting things up. We cut the odd-length top extrusion segment, plus we had to trim the so-called "distance tube" riding inside the top extrusion segment to make room for the swage fitting and plastic bearing fitted at the top of the forestay.
The distance tube, I should note, is a feature unique to Selden's Furlex furlers. It is essentially a plastic insulator that envelops the stainless steel wire forestay inside the luff extrusion and prevents the wire from ever contacting the aluminum extrusion itself. The distance tubes inside each extrusion segment are separated by a series of aluminum joining sleeves at the segment joints.
We were now ready to start putting everything together. The luff extrusion we assembled from the bottom up, starting with the first connection, which incorporates the luff feeder. This and all other extrusion segment connections are made with Selden's very clever connecting plates, which have little buttons on either end that fit inside corresponding holes in the extrusion segments and ride inside the segment joints atop the joining sleeves that separate the distance tubes.
This may sound a bit complicated, but really it's quite facile. You slide the distance tube and joining sleeve on a given joint up out of the way, fit in the connector plate, then use a stray length of joining sleeve to ram the pieces back into place inside the extrusion under the connecting plate. The little plate is thus neatly trapped, and everything is held tightly together, without the use of any invasive mechanical fasteners (which are likely to corrode, so that you can never get anything apart again) or unreliable roll pins (which are apt to fall out, so that everything comes apart when you least want it to).
Having joined all the extrusion segments together, we next slid the furler's halyard swivel over the extrusion's top end and installed the extrusion's top cap, which is secured with two set screws. We also slid the furler's bearing assembly up over the bottom of the extrusion. Note that there is one roll pin that fits through the body of the extrusion to secure the bottom interior sleeve in place. This not only is secured with Locktite, but is also physically held in place by the bearing assembly itself, which slides down over it and is itself fixed in place after everything is finally put together.
Now, at last, we were ready to slip the new forestay wire inside the assembled extrusion. First, however, we stretched out the wire and measured and marked it at 16.705 meters from the top, per our initial calculation. The very end of the wire as delivered is annealed and tapered at the factory so that it slides neatly through the center of the various distance tubes and joining sleeves inside the extrusion. As we threaded it down the extrusion after measuring and marking it, we wiped the wire with a clean cloth to make sure no dirt or grit got trapped inside. Then and only then did we cut the wire to length with our trusty hacksaw, which we fitted with a fresh blade to ensure a clean cut. To make sure the wire didn't unlay as we cut it, we taped it either side of our mark.
Next we needed to install the rigging screw, which has a Sta-Lok mechanical wire terminal incorporated into its upper end. Anyone who has assembled a Navtec Norseman terminal or a Sta-Lok terminal will be very familiar with this part of the job.
First we threaded the terminal socket onto the end of the wire, unlaid the end of the wire, and slipped the terminal's wedge cone over the wire's core. The core should protrude about 2 mm from the end of the cone. We then made sure the outer strands of the wire were evenly spaced around the body of the wedge cone, making sure in particular that no strands were trapped in the small compression slot that runs the length of the cone.
Next we took a pair of pliers and pre-bent the ends of the outer strands of wire around the end of the cone. We then dropped the forming bowl inside the terminal, screwed on the socket, and dogged it down tight with a pair of wrenches. We immediately reopened the terminal to check that the outer strands of wire had been pressed neatly around the cone; we also, again, wanted to be sure no strands had been pressed into the slot.
Everything looked neat and proper, so we applied some Loctite to the threads on the socket and screwed the terminal up tight again. When we were done, we opened the rigging screw as far as it would go (it has stops at the end so that it can't come apart), to ensure it would be easy to get the forestay on when it comes time to step the mast.
We then slid the bearing assembly into place over the rigging screw. The flats inside the assembly correspond to those on the body of the screw and must all be lined up properly for the former to fit over the latter. This also serves to lock the screw and keep it from turning under load. The bearing assembly is fixed in place over the screw with a clevis pin at the bottom, which fits through the lower end of the screw itself and is secured with a cotter pin, and a pair of set screws at the top, which seat into holes in the bottom of the luff extrusion.
The last bit of assembly consisted simply of snapping the furler pieces together around the bearing assembly. Prior to joining the two halves of the furling drum, we first threaded the bitter end of the furling line through its hole in the drum and secured it with a clip and set screw inside. All the other parts--the two drum halves, the exterior line guard that fits around the drum, and the line guide on the front of the drum--are carefully machined and fit together simply and neatly.
Last but not least, we carried the forestay, extrusion, and furler out to Lunacy's mast and pinned the forestay in place to the masthead.
Twas a gratifying experience, though the job isn't finished quite yet. Once the mast goes up and the forestay is on, I'll need to tighten up the rigging screw inside the drum and bearing assembly. This is easy to do. Pull the clevis pin at the bottom of the bearing assembly, open the two set screws at the top, and the whole business, drum and all, can be slid up the extrusion to expose the screw.
I also still need to install the extension link under the rigging terminal (it should arrive in the mail today) sometime before the mast goes up. Plus, once the mast is up, I also need to orient the line guide so it faces the furling line leads that run back to the cockpit. But again, this is easy. It's just a matter of opening another set screw and twisting the line guard and guide around the drum into the desired position.
So really, I think, the biggest problem I have right now is figuring out what to do with the old furler, extrusion, and forestay.
Here's a special offer for WaveTrain riders: it's yours, for free. Come and get it. First come, first served.
PS: A note to the Blog Integrity Police. No, Scott did not give me all this stuff, though he did give me a discount.