Rig tension

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YotMax
Inlägg: 10
Blev medlem: mån 03 nov 2008 02:44

Rig tension

Inlägg av YotMax »

Hi everyone,

I recently purchased a nice little M26 which I am very happy with. But last weekend, I was laying in the v-berth looking up through our foredeck hatch and noticed that the mast has a bend to port above the spreaders. So the starboard capshrouds need a bit more tension. Or the port capshroud needs slacking off.

I'm quite practiced at doing that but am always a bit hesitant to put more tension on without knowing whether I'm approaching any kind of limit. Does anyone have any good rule of thumb as to when the tension is enough? I'm not planning to do more than the occasional fun race so looking after the gear is more important to me than extracting the last fraction of a knot of boat speed.

Regards,
Max
Regards,
Max
M26 Sundancer
Sydney, Australia

The best cure for seasickness is to sit under a tree
(Spike Milligan)

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maja
Moderator
Inlägg: 2341
Blev medlem: lör 19 aug 2006 08:56
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Re: Rig tension

Inlägg av maja »

To fix your problem, the easiest and quickest way is to loosen the lower shrouds and adjust the uppers by loosen 1 turn at the time on one side and tighten 1 turn at the time on the other side until the mast is straight transversally. After that, tighten the lower shrouds symmetricallly so that only a slight longitudinal prebend of an inch or so will remain.

On the home page of Seldén Mast you may find rigging instructions in different languages. See http://www.seldenmast.com/frameset.cfm? ... m=86180222 On page 29 of this guide you will find an easy way to measure and adjust the rig, i.e. "The folding rule method".

For 5 mm upper shrouds the tension of an IF-boat or M26 should correspond to a deflection of about 1,5 and 2 millimetres per meter (corresponing to 3-4 mm following the "Folding rule method").

For 6 mm upper shrouds the tension should correspon to a deflection of about 1 and 1,5 millimetres per meter (corresponing to 2-3 mm following the "Folding rule method").

After adjustment of the upper shrouds, the lower shrouds are to be adjusted/tensioned so that the mast is straight transversally and a slight longitudinal prebend of an inch or so will remain.
Marek, IF-båt SWE-829 "Ingela" från Lagunen i Malmö
Medlem i IF-båtförbundet sedan 1985
IF-båtägare sedan 1983

YotMax
Inlägg: 10
Blev medlem: mån 03 nov 2008 02:44

Re: Rig tension

Inlägg av YotMax »

Thanks, maja. That's an excellent resource - well explained, logical and easy to implement too.

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