When To Use A Pull-Back - JBL VTX Series Rigging Manual

12.5 - WHEN TO USE A PULL-BACK

The use of a pull-back is best suited when the center of gravity (CoG) of an array falls outside the footprint of the Array Frame. Typically,
long curved arrays with a large down angle qualify for this condition. When this condition is true, LAC displays an error to indicate that
the array frame alone cannot achieve the down angle needed for the design (LAC - Example 1). In this case an A8 Suspension Bar
can be selected as the bottom frame, which moves the array CoG between the two suspension points. With the CoG between the two
suspension points, almost any down angle can be achieved (LAC - Example 2).
LAC - Example 1
Invalid CG Location
Center of Gravity
In this scenario, since the two suspension points (motors) are used to adjust the array angle, the pick-point flexibility of the array frame
is not needed. Using two Suspension Bars, one at the top and one at the bottom, can yield the same outcome while saving some weight
and cost (LAC - Example 2).
LAC - Example 3
Center of Gravity
Suspension Points
Suspension Points
VTX A8 | Rigging Manual
Center of Gravity
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LAC - Example 2
Suspension Points