A support assembly for supporting a remotely controlled instrument driver in a selectable orientation relative to an operating table, the assembly comprising including a base removably attachable to the operating table, an actuator assembly coupled to the base, the actuator assembly including an actuator and a brake that is electronically activated to allow rotation of a first extension member about a first axis substantially orthogonal to the operating table. A second extension member is coupled to the first extension member via an interface assembly operatively controlled by the actuator to selectively allow rotation of the second extension member about a second axis substantially parallel to the first axis, and about a third axis substantially orthogonal to the first axis.