Adjusting The Mechanical Limit Switches; Boom Balancing - Nice M3BAR Instructions And Warnings For Installation And Use

3.9 ADJUSTING THE MECHANICAL LIMIT
SWITCHES
To adjust the limit switches, proceed as follows:
unlock the gearmotor with the relevant key provided (refer
1.
to the "Manually unlocking and locking the gearmotor"
paragraph)
manually move the boom so that it completes a full
2.
opening and closing manoeuvre
turn the screws of the mechanical stops (A - B) to adjust
3.
the boom's horizontal position, when it is closed, and its
vertical position, when it is open
27
A
B
after making the adjustments, tighten the nuts vigorously.
4.

3.10 BOOM BALANCING

The boom balancing operation is used to find the best balance
between the overall weight of the boom, inclusive of the installed
accessories, and the force opposed by the tension of the
balancing spring.
To verify the spring tension, proceed as explained below.
For models M-BAR ("Figure 28")
unlock the gearmotor with the relevant key provided (refer
1.
to the "Manually unlocking and locking the gearmotor"
paragraph)
manually move the boom to about half-way (45°) and
2.
leave it stationary
if the boom tends to rise, reduce the tension of the spring
3.
(A) by manually turning the latter clockwise. On the other
hand, if the boom tends to fall, increase the tension by
manually turning the spring anti-clockwise.
Note The imbalance is acceptable when the force required
to move the boom during the opening and closing
manoeuvres and in all other positions is less than or
equal to half the nominal value. The force required is
therefore equal to roughly 1.5 kg for M3; 3.5 kg for M5;
4.5 kg for M7. The force is measured perpendicularly to
the boom at 1 m from the rotation axis.
62 – ENGLISH
28
45°
45°
repeat the operation by positioning the boom also at
4.
roughly 20° and 70°. If the boom remains stationary in
its position, it means that it is correctly balanced; a slight
imbalance is allowed, but the boom must never move
substantially
loosen the nut (B) to block the balancing spring
5.
lock the gearmotor.
6.
For models L-BAR ("Figure 29")
unlock the gearmotor with the relevant key provided (refer
1.
to the "Manually unlocking and locking the gearmotor"
paragraph)
manually move the boom to about half-way (45°) and
2.
leave it stationary
if the boom tends to rise, reduce the tension of the spring
3.
by turning the nut (C) clockwise. On the other hand, if
the boom tends to fall, increase the spring tension by
manually turning the nut (C) anti-clockwise.
29
45°
45°
Note The imbalance is acceptable when the force required
to move the boom during the opening and closing
manoeuvres and in all other positions is less than or
equal to half the nominal value. The force required is
therefore equal to roughly 6.5 kg. The force is measured
perpendicularly to the boom at 1 m from the rotation
axis.
B
A
C