Hi Steve, The following is from the 1990 Owner's Manual for the C&C 37+ (which has rod rigging so you can't use a normal Loos gauge). It should be similar to the 34+
Hope it is of some help. Scroll down past your email copied below. Ken H. On 8 February 2014 12:08, Stephen Thorne <[email protected]> wrote: > > Folks, > > Has anyone developed a ratio for tuning a C&C 34+ rig using a loos gauge ? > > Thanks > > Steve > 34+ Deja Vu > New Orleans > > Sent from my iPhone > > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > [email protected] > 4.3 Tuning at the Dock All turnbuckles are equipped with toggles at their base which eliminates bending load on the swage and turnbuckle threads. Toggles are fitted to both ends of the forestay. As the boat tacks and the headsail loading varies from side to side, the forestay terminals are subject to extreme fatigue loading. Start tuning the spar by ensuring that the mast is in the centre of the boat, perpendicular to the designed transverse waterline. Your boat may not sit level at the dock due to distribution of gear, stores and tankage levels, so check the waterline position both sides. Then slacken the lower shrouds completely by undoing their turnbuckles. Take the main halyard and lead the shackle end to a point on the rail or chainplate. Adjust the halyard so that the shackle just touches the reference point on the rail or chainplate with a given downward tension, and then cleat the halyard. Then take the halyard to the same reference point on the other side of the deck. With the same amount of downward tension, you will be able to just touch the shackle to the reference point if the mast is plumb transversely. lf not, let off one upper shroud turnbuckle and take up on the other in order to bring the masthead closer to centerline until the halyard shackle touches both reference points under the same downward tension. The particular part of the rail or deck you choose as your reference point is not important as long as it is the same point on each side. Once the mast is centered transversely, tighten both upper shroud turnbuckles uniformly, one full turn one side, then one full turn on the other. Repeat until the turnbuckles become difficult to turn. Pin the turnbuckles. Tighten the lower shroud turnbuckles so that almost all of the slack is removed; the center point of each lower shroud should have about 1 inch of play in either direction. Sight up the aft side of the mast to make sure that it is straight. The lower shrouds may require adjustment to straighten the mast. Now check the rake. Rake is the fore and aft angle of the spar. The C&C 37+ spar is designed to carry up to (approx.l 12 inches of rake. Rake effects the position of the centre of effort of your sail plan and, consequently, the balance of the helm. The effects are more pronounced in heavier winds. The extent of rake on your boat should be determined by your particular sailing characteristics, the typical local wind conditions and your sailmaker's suggestions. Forward rake should be avoided. The main halyard may be used to measure rake. In calm wind and sea, with the boat floating level on her lines, hang a plumb weight or equivalent, such as a hammer or wrench, from the main halyard. Adjust the halyard so that the weight is suspended just above the gooseneck. The fore and aft distance between the mast and the halyard at the gooseneck level is the amount of rake. Ease off the forestay turnbuckle and tighten the backstay turnbuckle (or vice versa) until the desired rake is achieved. Pin both fore and backstay turnbuckles. Unless the rake has to be readjusted in the future to correct helm balance, these turnbuckles will need no more adjusting. Additional tensioning may be applied by the backstay adjuster. Check that the outboard ends of the spreaders are padded and taped to avoid chafing the genoa. Ensure that all turnbuckles are pinned. The mast should be fixed at the step to prevent fore and aft movement and to hold the mast in the step. You are now ready to complete the tuning procedure while sailing. 4.4 Tuning While Sailing Select a day with a steady I to 12 knot breeze and reasonably flat sea. Put the boat on starboard tack, close hauled. Sight up the luff groove of the mast. If the mast seems to fall off to leeward at the spreaders, luff up slightly and tighten the starboard lower shroud as necessary. Put the boat back on the wind and check the spar again, adjusting as necessary. When the mast appears straight, bring the boat about and do the same on the port side. Check the following carefully. *First, when the upper shrouds are at optimum tension, when at about 15 to 20 degrees of heel, the leeward rigging should look slack. This is quite appropriate and should never be tightened. *Secondly, when close hauled under genoa and main, the forestay may appear quite sagged. Tensioning the backstay will reduce the amount of sag, but the sag itself can never be eliminated. As a rule of thumb, the maximum static backstay pressure should never exceed one quarter of the backstay breaking strength. (See table 2, Standing Rigging and Table 5, Backstay Preload Limits.) lf your boat is brand new, the rigging may seat and stretch to the extent that tuning from scratch again will become necessary in a matter of weeks. However, after this initial working-in period, you will find that the rig tends to hold its tune for considerably long periods of time. After becoming used to the feel of the boat, you may wish to either increase or decrease the amount of weather helm. Any sailboat, when sailing up wind, should have a slight tendency to "round up" or head into the wind if the helm is let go. However, if you find it typically difficult to hold the boat off the wind, the boat is carrying to much weather helm. This can be alleviated by reducing rake which will move the center of effort of the sailplan further forward" Conversely, if you find the boat tends to fall off when sailing upwind and you must constantly push her to weather, then the boat carries lee helm and the rig will require more rake. With constant tuning as the season progresses, your boat's performance will improve. The boat will feel more comfortable to sail. You will find that tuning is a bit of an art, yet you will begin to notice subtle changes in the behaviour and response of your boat as you make subile changes in tuning. The important thing to remember is to go about the process in a slow and orderly fashion. To record the details of the tuning and retuning procedures as well as the results achieved will provide you a better understanding of the rig and will serve as a useful reference for rigging the boat on subsequent occasions.
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