mast geometry

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lloyd

I have changed the shrouds on my mast,and I want make sure the mast is put up correctly.Are there measurements to take to make sure the mast is actually not too forward,or tilted too far back?LLOYD
 
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Justin - O'day Owners' Web

Not exactly

Mast rake is part art and part science, and will vary from boat to boat and according to tuning preferences on any given boat. You should start by putting the mast to vertical and seeing how the boat sails, then adjust from there. Put the rig up and tighten the shrouds so that the mast is secure. tie something that weighs a few pounds to the end of the main halyard. hoist it just a bit so that the weight - a wrench is ideal - is at about the level of the gooseneck. Now you can see how far the mast is canted in any direction by seeing where the weight hangs. If the mast is centered laterally and fore and aft the weight will hand right against the mast. Justin - O'day Owners' Web
 
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Vic

Just be careful who is standing ...

where, especially on a light boat if you are going to use a plumb bob. Vic
 
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lloyd

mast geometry follow up for Justin?

I was having a big problem getting the boat to come around to windward,both with a genoa and a standard sized jib.I am hoping to check and/or correct any unknowns,that is why I want to check the mast angle.The boat is on its trailer now,and I understand what you where saying re: a plumb bob procedure,but how do I know if the boat is level on the trailer?Is there part of the boat that is actualy "level" or paralell to the water so I can put a carpenters level there and know that the mast is or isnt straight up because the boat isnt level on the trailer? Any info would help.LLOYD
 
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Justin - O'day Owners' Web

Musings on mast rake from a non-expert...:)

No, there is no absolute level to work from. Firstly, I'd try doing this routine in the water. Sail the boat, try and fix in your mind how it trims out underway, and use that as a guideline to start from - What really matters is the dynamic tuning anyway so where you zero 'vertical' to doesn't matter much. Too much lee-helm - bring the mast aft. Too much weather - helm - bring the mast forward. My guess is you need to go aft. Moving the center of effort aft relavtive to the center of lift generated by the keel will make the boat want to pivot into the wind and assist with tacking. I like my rig set up so that if I let go of the stick in our typical winds - here you can bank on 12 - 15 knots from the SSW most afternoons - the boat heads up but not quite into irons. That means that neutral helm makes the boat come most of the way toward a tack without control inputs - it doesn't take a ton of input, or speed robbing drag, to push the nose through the wind. Others may prefer other setups. I'm probably inducing more drag than necessary when sailing straight because it takes more helm to keep the boat from heading up. Justin
 
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