Homemade roller furler
Posted: Sun Feb 08, 2015 8:27 pmI was doodling at work one day (don't tell the boss!) and wondered if I could make my own roller furler system. You need a swivel at the top and bottom of the jib, and a rotatable drum to hold the furler line. A big problem for any home-made system is strength: the 5/32" wire rope in the jib is rated for 730 pounds safe load, so any system I come up with should be as strong, or stronger.
I ordered two 1/4" stainless steel swivels (SD-182206). The top swivel is connected to jib and a block for 2:1 halyard line. The bottom swivel is connected to bowsprit/jib. The bottom swivel has a circular drum attached to it and fixed into position by a screw driven through the wood and through the upper eye of the swivel. When the drum is rotated, the swivel will rotate, thereby rotating the jib and furling it. Pulling on the jib sheet reverses the process as it should, causing the furler line to rotate around the drum. ALL of the force is carried by the swivel; the drum only takes on force when you are winding the jib, and this force is fairly negligible.
My drum is cut with a 2 1/4" hole saw, with the interior cut out with a 2" hole saw (or similar - just make it the correct size to fit your swivel). Top and bottom of the drum are 4mm plywood with the hole cut out of the center. I think I used 3/4" overhang on the plywood, but I should have made it wider to fit more furler line. The line is dead-ended through a hole in the drum. Placement of a fairlead is critical. I had a problem where the line would "jump" over the top plywood. That could be solved by using a wider overhang of plywood (a "wider" drum), or in my case, by placement of a fairlead extremely close to the drum to force the line to furl closer to the middle of the drum.
I've been very pleased with performance so far. I can furl the jib even in heavy wind. I like the low cost and natural wood appearance of this unit, though of course you give up a "professional" look, a slightly easier to use unit, and the smooth ball bearings of the Harken roller furler.
I ordered two 1/4" stainless steel swivels (SD-182206). The top swivel is connected to jib and a block for 2:1 halyard line. The bottom swivel is connected to bowsprit/jib. The bottom swivel has a circular drum attached to it and fixed into position by a screw driven through the wood and through the upper eye of the swivel. When the drum is rotated, the swivel will rotate, thereby rotating the jib and furling it. Pulling on the jib sheet reverses the process as it should, causing the furler line to rotate around the drum. ALL of the force is carried by the swivel; the drum only takes on force when you are winding the jib, and this force is fairly negligible.
My drum is cut with a 2 1/4" hole saw, with the interior cut out with a 2" hole saw (or similar - just make it the correct size to fit your swivel). Top and bottom of the drum are 4mm plywood with the hole cut out of the center. I think I used 3/4" overhang on the plywood, but I should have made it wider to fit more furler line. The line is dead-ended through a hole in the drum. Placement of a fairlead is critical. I had a problem where the line would "jump" over the top plywood. That could be solved by using a wider overhang of plywood (a "wider" drum), or in my case, by placement of a fairlead extremely close to the drum to force the line to furl closer to the middle of the drum.
I've been very pleased with performance so far. I can furl the jib even in heavy wind. I like the low cost and natural wood appearance of this unit, though of course you give up a "professional" look, a slightly easier to use unit, and the smooth ball bearings of the Harken roller furler.
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