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Old 05-09-2016, 18:27   #1
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Mast Shape

I am looking at a 33.6 hunter 1996. The mast doesn't go straight up. It looks like it is arched aft. Is this normal or is the rigging torqued the wrong way or too much?

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Old 05-09-2016, 18:54   #2
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Re: Mast Shape

Looking on The designer has raked the main aft quite a bit. Looks to me the Main is the source or power for this boat. Foretriangle is pretty small. Bending the mast is used to shape the main more efficiently. I played with different adjustments on my boat to improve performance over the years, getting small or no improvement.
Now I raise sails, fiddle with them a little, Then enjoy myself.

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Old 05-09-2016, 18:56   #3
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Re: Mast Shape

What you're seeing is likely a combination of pre-bend, & induced bend. The former can be done when the spar is built, or at any time in it's life. And the latter is tuneable via the shrouds, stays, deck blocking, & step position. With the amount o bend varying from boat to boat (design) as well as on how a boat is tuned for prevailing conditions, & so that the spars work well in conjunction with the sails.

However there should be a set of measurements available which state what the normal range of bend on this boat's spar are. Available from; the designer/the original plans, owner's associations, tuning guides for the boat, or owner's associations.

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Old 05-09-2016, 18:58   #4
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Re: Mast Shape

How many boats have masts that go straight up?

Most have some degree of rake (angle from the vertical) and prebend.

Most fore-and-aft sails (aka leg of mutton sails) are not triangles - even if they have 3 angles or corners. Sails are shaped.

Prebending a mast modifies (accentuates or diminishes) that sail shape. Bending underway further modifies the sail shape.

Some reading:

Mast Rake and Mast Prebend and Bend Sailboat Rig Tuning Guide

Bend for Speed | Sailing World
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Old 05-09-2016, 19:00   #5
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Re: Mast Shape

That's called "pre-bend". Most masts have some degree of it, as well as some degree of "rake" Sorry, don't know how much of either is typical on a Hunter, but I'm sure the info is out there if you search on Hunter 33.6 and pre-bend.
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