Usually, torque brakes are only needed when the fasteners
to be tightened are vertical (or semi-vertical) and the
nutrunner must be repositioned at the 3rd Axis.
Example 1: All fasteners are horizontal: typically, no torque
brake is required because the arm geometry withstands the
torque.
Example 2: All fasteners are vertical and the nutrunner has
an in-line shape. There is no reason to spin or reposition
the nutrunner at the end of the arm and no torque brake is
required. The nutrunner can be fixed at the end of the arm
and the arm geometry withstands the torque.
Example 3: Several fasteners are significantly off vertical (but
are not horizontal) and are arranged in a long row. In this
case, the nutrunner has to be twisted slightly with respect to
the arm as each fastener is engaged and a torque brake at
the 3rd Axis is required.
Example 4: All fasteners are vertical and arranged around the
perimeter of a hub. The nutrunner has a right-angle shape.
The operator must reposition the nutrunner at the 3rd Axis
with each fastener to avoid interfering with the hub, and a
torque brake is required.