COMEUP Compact Winch (Ver:00) - Manual (Page 9)

7
Calculating Fleet Angle
● The winch should be mounted as close to centre
and as perpendicular as possible to the direction
of the line pull. This will keep the wire rope fleet
angle centre on the drum as small as possible.
● If the proper fleet angle is not maintained, the wire
rope could wind onto one side of the drum.
Experience has shown that the best wire rope service is obtained if the maximum fleet angle
is not more than 1.5° for smooth drum.
For example, the correct distance varies according to drum length.
D/d Ratio
It means ratio of pitch circle diameter of drum to the rope diameter.
In principle, a 12:1 D/d ratio is suggested for most pulling application and a 15:1 D/d ratio for
lifting and lowering applications. For example, a CWL-200 comes with a 95 mm dia. drum and
a 5 mm x 46 m wire rope, therefore its D/d ratio is calculated as follow.
D/d ratio = (95 + 5 mm ) /5 mm = 20 times
Rope Safety Factor
The working coefficient of the wire rope shall be determined from the ratio of the minimum
breaking force of the rope and the maximum possible lifting capacity.
In principle, a 3.5 times of rope safety factor is suitable for most pulling applications and a
5 times for lifting and lowering applications. For example, a CWL-200 comes with a 5 mm
x 46 m wire rope with 1,270 kg minimum breaking force, therefore its rope safety factor is
calculated as follow.
Rope safety factor =1,270 kg / 200 kg = 6.35 times
θ
θ
Correct Distance
Drum Length
Fleet Angle
Model CWL-80 CWL-200 CWL-301 CWL-200L CWL-301L
Drum Length 46 mm 97 mm 147 mm
Correct
Distance
87.4 cm at least 1.84 m at least 2.79 m at least