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3.3.3 CK-400 bottom unwinder
The CK-400 unwinder is equipped with tension arm and brake system to ensure a constant
film tension during unwinding (see fig 3.5). Place the film roll so far on the spindle till the core
reaches the cone on the end of the spindle. Now activate the clamp system by turning the
serrated knob to the right. This moves the three ridges out of the spindle to centre and clamp
the film core. The film has to be placed on the spindle and routed as shown on the routing
picture.
In the rest position the spindle is held by the brake system. When the tension arm is pulled
forward during unwinding the brake will be released to unroll the film. The tension arm is
connected to a spring, which brings the arm back to its start position at the end of the film
advance.
Each film advance of the machine will pull the tension arm forward. This will be checked by a
sensor which is placed just behind the tension arm in the blue brake box. If the arm stays at
its position during transport, the machine will stop with the message “running out of film”. If
there is still film on the roll, than the core is slipping on the spindle and the clamp system
needs more friction. Turn the ridged knob more to the right to create more friction to the film
core.
Figure 3.5 CK-400 unwind
Tension arm
Tracking adjustment knob
Spindle with
clamp system
Sensor position