Mast pre-bend template

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cfwahl
Posts: 79
Joined: 23 Nov 2003, 23:01
Location: CAN 62

Mast pre-bend template

Post by cfwahl » 01 Oct 2005, 22:54

I'm getting ready to build my first rig, and am up against mast pre-bend. It would be useful to have a template. I realize that the "proper" bend depends to some extent on the cut of the particular mainsail being fitted, and on various other choices, such as spreader mounting height, shroud configuration, mast ram height, etc. But a template for a mast that's thought to be relatively successful would be a helpful starting point.

So if anyone would volunteer to trace their unrigged pre-bent 11.1 mm diameter A rig mast, and scan the result to PDF, or publish the coordinates of offsets from a straight line, that would be a great public service. If nobody steps up to the plate/wickets, I may do this locally (using a colleague's rig).

Thanks,
Charles Wahl

Lester
Posts: 611
Joined: 14 Oct 2004, 22:29
Location: GBR 105
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Post by Lester » 01 Oct 2005, 23:00

The SAILSetc rigging diagram shows the masthead 40 mm off vertical for No.1 rig. I'm told that the bend should be in the upper 67% of the mast. As you form the bend, check what you have by wedging the mast heel against a wall, holding the mast at the jib forestay attachment point, and flexing the mast head as though tightening the backstay. You'll set the mast into the kind of bend it'll take up when rigged, and can check you like what you see.
Lester Gilbert
http://www.onemetre.net/

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