ProFurl MK0, Installation Manual

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MK 0
26
IN-BOOM MAINSAIL REEFING-FURLING SYSTEM
MK 0
MAINSAIL DESIGN SPECIFICATIONS
1. GEOMETRY
a) Luff curve design:
The luff curve design is one of the most essential points in the design of the mainsail
as it will determine how the sail will roll back and forth on the furling mandrel to avoid
overlapping of the luff tape, avoiding also the rear end of the boom to go down when the
sail is being rolled.
Starting with the mainsail fully hoisted :
Stage 1 : when beginning to roll the luff tape has to move backwards up to
the stage where a small crease appears between the feeder and the clew.
Stage 2 : the luff tape has to move to forward till the stage where the luff tape gets
close to the forward end of move backwards till the sail is completely furled.
b) Luff curve:
In reference with a straight line between the tack and the
head, if the angle due to the luff curve is backwards the luff of the sail will roll
backwards.
•
Luff curve has to be
“
S” shaped from tack to head: negative in the lower part of
the luff, positive in the upper part.
•
Maximum value of the curve (from straight line between head and tack) in % :
0.2% of luff length. If the mast has a camber just follow the same
correction to luff curve as you would do with a conventional sail.
•
Point of maximum negative curve at 20% of luff length measured from the tack.
•
Point of maximum positive curve at 60% of luff length measured from the tack.
c) Foot curve design.
Value : maximum 1% of foot length at 50% of foot length.
d) Roach:
Value: maximum 6% of leech lenght measured at 50% of leech length.
e) Angle between luff and foot (luff and foot being a straight line) : 88°
2. LUFF TAPE MATERIAL
Luff tape material must be made with a plastic PVC material with 4,5mm diameter, and
sailcloth tape with Teflon, to obtain a 5mm finished luff tape diameter.