A robotic arm compensator includes a housing, a lock mandrel, a first lock slide, a second lock slide and an instrument attached to the lock mandrel. A method of using the robotic arm compensator includes moving the first and second lock slides in a direction toward each other to engage the lock mandrel in a first state and moving the lock slides apart from each other to disengage the lock mandrel in a second state for providing exceptional radial movement, large lateral travel relative to overall size, zero force to utilize the compensation travel and no axial compressibility.