Stearn Sailing Systems Furler
Steam Twinstay One / Dynafurl One
Troubleshooting
The standard considerations in all furling system installations are:
Halyard angle -- angle should be aft of parallel to the luff when the sail is fully hoisted. On many masthead arrangements this will require a halyard pullback device installed on the mast. (See Accessories)
Halyard Swivel Height -- halyard swivel should be within 12" of the halyard sheave when the sail is fully hoisted. On shorter sails, this will require a wire pennant attached to the sail at the top (for performance), or at the bottom (for visibility). To check Halyard Swivel height, or to measure for a pennant, carefully hoist the Halyard Swivel with the sail attached to it, but not attached at the tack. When sail is fully hoisted measure from the tack of the sail to the tack pin, or shackle, on the furling drum. Pennant should be 6-12" shorter than this measurement and preferably, attached directly to the sail.
Furling line Angle -- furling line should enter the drum at 90 degrees to the luff. This is achieved by adjusting the position of the furling line block or fairlead closest to the furling drum.
Furling line Tension -- Furling line should always be under tension when the sail is being unfurled. Leading the line through a ratchet block mounted aft of the operator is usually a big help.
Furling line Jam -- there should not be so much line on the drum that it binds against the drum cover when fully wound for any particular sail. Start with the sail rolled up. There should not be more than 3 wraps on the drum when the sail is tightly furled with the sheets wrapped around it twice. If you cannot get enough line on the drum to completely unfurl the sail, then the line you are using is too large. Reduce line size or, remove the core in the forward third of a braided line. "Coring" the line will reduce the amount of space it takes up and cause it to lie flatter on the drum. This should be done in all furling installations using standard braided line, as it reduces fouling and overrides while still giving you a full diameter line in the cockpit. Some systems, notably Hyde and Stearns, are best suited for wire/rope furling lines in many applications. (See Accessories)
If you are experiencing trouble with your Stearns system that is not related to any of those items above, it is usually one of the following problems:
System doesn't rotate smoothly - With reduced backstay tension and no tension on the furling line, grab the drum and rotate the system by hand. If it feels rough or bumpy it is time to replace the Terminal End bearings, torque nuts, and O-rings. (See Bearing Replacement Kits)
Hard to furl - If you've already checked the Terminal Ends (System doesn't rotate smoothly, above) then it's time to check the halyard swivel. Lower the sail and rotate the top of the Halyard Swivel while holding the bottom. It should rotate smoothly and easily. If not, you need to replace the Halyard Swivel bearing. (See Bearing Replacement) Also be sure to check the white Delrin Inserts between the halyard swivel and the rod. Make sure that they are firmly in place and that they fit snugly against the rod. If they are sufficiently worn they can allow the Halyard Swivel to cock to one side. This will increase the effort needed to furl and they should be replaced.
