How critical is level and how accurate does plumb have to be with your floor mounted jib cranes?

The vertical column of a floor mounted crane should be fairly plumb. These cranes rotate very easily. With a load on the boom, if the column is not plumb, the boom may rotate by itself. In order to prevent unwanted boom rotation, it is certainly beneficial to spend extra time insuring the column of a floor mounted jib crane is plumb. ... more