John
First of all, the guys who really know how to make the boat go fast may not wish to share their specific tuning secrets on line, and secondly the tune is a bit boat specific and owner specific as well, it is a lot about what you like on your boat. Ill give you some idea of how I approach tuning, but I recognize that many on here probably know a lot more about the subject than I do. Basically you need to get your mast up plumb, side to side and fore and aft with minimal shroud tension, just enough to hold it in place, and then introduce about 8-10 inches of rake by adjusting the mast position fore and aft at the mast step. In calm conditions, and not introducing a lot of movement on your boat by moving your own weight around drop a heavy weight suspended from the main halyard and note when the weight suspended just above the gooseneck hangs 8-10 inches aft of the mast. Check fro plumb side to side with the main halyard fastened to the toe rail on either side and tensioned equally on each side as you move it back and forth from one side to the other exact spot on toe rail each time plumb side to side is when the length of halyard marked at some convenient spot after it exits the mast is the same on each side. Set you upper shrouds, incrementally using initially about 2 to 3 turns on the turnbuckles each side, one after the other, measuring tension each time after you do this. I would guess that 1000 would be a good starting point upper shroud tension on your 29 MKII so as you approach 1000 on each side then do one turn on each turnbuckle at a time and then maybe ½ a turn each time until you get a measure of 1000 on port and stbd upper shrouds. Now do the lowers same way but tension those to about 600. If you have the check stays then set those turnbuckles only hand tight and leave them alone. Go for a sail, noting leeward side shroud sag on a beat, tacking back and forth to get an idea if that seems equal for stbd and port tacks. Also while on the beat each tack sight up from the base of the mast ( lie down on your back to look straight up the forward line of the mast if you must) to see what the mast looks like. It should bow a little towards leeward, maybe 3-5 inches maximized at the spreaders which you will have to estimate, but I believe that you boat will work best with that leeward bow as opposed to a perfectly straight mast on a beat and that is why the lowers are tensioned to a lesser level than the uppers. With sails down and preferably on the hook again in calm conditions, check to see that the mast has remained plumb side to side and check the rake. If things changed as a result of the mast and stays settling in a bit under sail then do some fine tuning again and after that seize the turnbuckles with wire or whatever I get away with using plastic electrical tie wraps but I would change those out for metal for offshore cruising. When you are doing the at dock tuning set your backstay tension to about 800. In heavy air and after you have the tune you like you can use that backstay if you have on the fly adjustment capability to bring the top of your mast aft while going to weather up to about 2000 on the backstay or you can release tension and let it go forward when sailing downwind which should help with speed. I am guessing at your numbers based on my experience with my C&C 27 MKIII and now with my C&C 35 MKII. You need to try it for yourself and it helps a lot to have the proper shroud tension gage and it does take time. I spend hours experimenting with my rig tune and I dont even race anymore and I check the tensions after every couple of sails, especially if we encounter heavy air. Good luck and please the rest of you dont beat up on my suggestions here too bad, just trying to help a fellow sailor. Dwight Veinot C&C 35 MKII, Alianna St. Margarets Bay, NS _____ From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of johnr...@aol.com Sent: April 3, 2014 9:27 AM To: cnc-list@cnc-list.com Subject: Stus-List Lookin' Good Goin' Slow I have to chuckle a bit in that my post re Poli-Glow has elicited a flood of discussion and my post re tuning my rig has (finally) received one response. Thanks to you all and especially to Bob for the reply on tuning. As a friend at the club observed after a club race: "You guys gotta be green with envy when you sail by me. I look sooooo fine!" Cheers, John McLaughlin C&C29-2 "Falcon"
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