Transcript
Star Tuning Guide
Mark Mendelblatt and Brian Fatih, Weymouth Test Event 2011 using Doyle M11 and J8 Photo Credit: Leandro Spina
Mast and Rigging Set-up Before stepping the mast you'll need to measure and adjust the intermediate diagonal lengths and spreader sweep. With the mast supported on stands start by pulling the upper shrouds taught along the front of the mast and marking the position of the clevis pin hole on the mast (most mast builders have previously marked this position already on the front of the spar a few inches below the spreader bracket). The intermediate shrouds can then be pulled taught along the front of the mast and adjusted evenly to a length of 73 mm (2 7/8") below the uppers mark on the mast. Then tighten the locking nuts with lock-tight and taping so the nuts won't back off.
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With the lower cap shroud pinned into the upper cap shroud each shroud and turnbuckle should then be pulled taught along the front of the mast to check that they are adjusted evenly in length before the caps and intermediates are pinned to the spreader tip. Once the cap shrouds turnbuckles are adjusted evenly they should be held in position until the mast is stepped. Repeat the same procedure with each of the lower shrouds and turnbuckles to assure they are even side to side before stepping the mast. With the spreaders attached to the mast the spreader sweep can be checked by tensioning a string between the spreader tips and measuring to the 134mm (5.25") to the aft edge of the mast. Place a batten on the flat surface of the mast step to sight the spreader sweep is even side to side. Generally the mast builder installs tape marks on underside of the spreaders 457mm (18") from the tip for jib trimming reference marks. The shrouds can then be attached to the spreader tips and the masthead Windex mounted securely before stepping the rig. The forward pin on the mast step should be positioned so the aft edge of the mast step in the upwind position is approximately 4520mm (14' 10") measured from the aft intersection to the transom and the deck. The aft pin should be positioned near the back of the step to allow the mast to rake forward downwind when the backstays are eased. Pull the headstay taught along the front of the mast and mark the position of the top of the lower black band on the headstay. Once the mast is stepped, the headstay can then be adjusted so that the distance from the reference mark to the deck is 940mm ( 37") as a base setting. The upper shrouds should be placed forward of the lower shrouds on the chain plates (or cars if provided). Once the running backstays, headstay and shrouds are attached you should then just tension both upper backstays evenly until the headstay just stands firm (the lower backstays (check stays) and lower shrouds must all be slack) to check the cap shroud tension. The cap shrouds turnbuckles should be adjusted first by counting turns and adjusting evenly on each side until the base setting of 24 (on the PT-2 Loos gauge) or (32 on the older Type A Loos gauge) is achieved. Make sure the mast puller is slack when checking the cap shroud tension. Now the lower shrouds can be tensioned evenly by counting the same number of turns on each until the slack is removed and the lowers are just firm. With the lowers firm then ease both lower turnbuckles off two full turns (12 faces off staymaster turnbuckle) and this will be your base setting. The jib lead position measured from the headstay to the bearing point of the jib block. On the J6R, it should measure 86.5" and on the JH8 should measure 87". Once the boom, mainsheet, outhaul, vang and Cunningham are attached and rigged you should be ready to slide the rolled main on the boom and then attach the jib tack and jib sheets onto the rolled jib on the foredeck. Try to raise and lower the jib while protected from the stronger winds so the zipper luff does not get damaged. Also keep the main outhaul eased when raising or lowering the mainsail
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to prevent the luff rope, vision windows and/or tack slug from overloading. Once the main is hoisted the lower luff rope can be fed down the mast slot below the feeder (before lowering the main it’s a good idea to slide the lower luff rope back out of the mast slot to prevent damage to the mainsail).
Sailing While sailing close hauled the outhaul should first be tensioned to within 25mm of the black band in light air. As the wind speed increases over 8 knots the outhaul should gradually be tensioned to 15mm to keep the lower batten open. If the wind lightens under 7 knots, the outhaul should be eased back out to 25mm gradually to add power to the main. Trim the mainsheet so that the telltale at the top batten stalls about half the time. The telltale at the upper middle batten should not stall more than a third of the time. In these lighter wind speeds I like to lengthen the headstay 6 to 12mm (37.5") to increase helm and keep the leech of the main open. The jib tack should be eased some to keep some wrinkles in the luff of the jib in light air to make the jib fuller especially when the ram is on and the headstay is sagging for power. The tack of the jib will be 0 to 1" above the deck. The leech of the jib will be almost to the mark on the spreader or just keeping the leech telltale flying. The main Cunningham should not be tensioned until the wind increases over 7 knots (the diagonal wrinkles in the luff help add power to the main by converting the excess luff curve into increase cord depth and power in light conditions). As the wind speed increases to over 10 knots the Cunningham should be tensioned to help flatten the mainsail and keep the leech from closing down. In very light wind speed (under 5 knots), we recommend tensioning the forward mast puller (ram) while sailing closehauled to prebend the mast and open the upper leech to keep the leech telltales from stalling. The ram (mast puller) also helps keep the headstay loose which helps power up the jib in light conditions as well as keep the main upper leech open. Often in very light conditions when using the ram to prebend the mast we will ease the outhaul to compensate for the prebend. Once the wind speed reaches 5 knots, we recommend releasing all the ram since the wind is strong enough to open the upper leech of the main. It is not uncommon to have to make several ram adjustments as the wind speed changes between 1 and 5 knots. In wind speeds 8 - 12 knots (max power) return the headstay to base setting 950mm (37.25") to as short as 37". The mainsail can be trimmed to two blocked and the outhaul tensioned to 10 - 15mm from the band. The jib in these conditions can begin to be smoothed out on the luff by tensioning the jib tack. The leech of the jib will be trimmed to the mark on the spreader. In general, don't use much mainsail Cunningham in these max power conditions. You will not need any tension on the upper runner backstay upwind in these conditions either. You may need to use a little lower runner (check stay to power up the main when needed).
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As the wind speed increases over 13 to 16 knots tighten the cap shroud turnbuckle one turn. The outhaul should be tightened from 10 to 0mm from the band. The Cunningham should be tensioned to flatten the main and keep the leech open. The jib tack will be tensioned to remove all the luff wrinkles. Make sure the jib halyard is high enough to still trim the jib properly on the spreader and keep the luff tension smooth. The check stay will need to be tensioned quite a bit to avoid to much over bending of the mast. The upper runner can be tightened in the puffs to depower and then eased some in the light spots. When the wind speed increases over 16 knots, increase the cap shroud load to 25 on the Loos gauge. It may also be a good idea to lengthen the headstay again in the heavy air to 6 to 12mm (37.25" to 37.5") to help depower the mainsail and keep the boat balanced. The Cunningham should be tightened to max and the outhaul pulled to max as well. The runners tension helps keep the mast from over bending and the headstay from sagging too much and overpowering the jib. It is a good time to be using a flatter jib such as the J2-H. When heading downwind, the leeward runner must be eases first followed by the mainsheet and Cunningham on the offset leg. While the running backstay is being eased, the puller must be tensioned to keep the mast from inverting. Once the backstay is eased to the downwind position, the puller (ram) must be on all the way. (It is a good idea to mark your backstay tails for the correct downwind position for each wind speed). The main outhaul should be eased and vang tension adjusted for the wind speed. Once the whisker pole is attached and the jib sheet eased to set the pole the jib tack can be released and the coarse jib halyard raised.
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