A motion generator having a moveable end effector, which system comprises: an end effector in the form of a platform; a stationary support having a base; exactly one first tensile member attached to the end effector in the horizontal centre of gravity of the end effector, and at least six second tensile members, wherein the first tensile member applies a force in the upward direction, where the second tensile members apply a force in the downward direction, wherein each of the first tensile member and the at least six second tensile members comprises an elastic element and each of which tensile members being attached at one end thereof to the end effector and being attached at the other end thereof to the stationary support; and wherein each tensile member applies a tensile force between the end effector and the stationary support, wherein each one of the at least six tensile members is independently adjustably tensioned by an actuator fixed to the stationary support which acts on the tensile member at a point along its length between the end effector and the elastic element, wherein the actuator acts to change the tension in the part of the tensile member between the end effector and the actuator in order to affect the forces and moments applied to the end effector by the system, wherein the actuator reacts the tensile force it applies to the tensile member against the stationary support, and wherein the tensile force applied by each tensile member to the end effector reacts against the tensile forces applied by the other tensile members via the end effector such that the end effector is maintained in suspension and out of contact with the stationary support by the tensile forces in the tensile members and any other forces applied to the end effector. an end effector in the form of a platform; a stationary support having a base; exactly one first tensile member attached to the end effector in the horizontal centre of gravity of the end effector, and at least six second tensile members, wherein the first tensile member applies a force in the upward direction, where the second tensile members apply a force in the downward direction, wherein each of the first tensile member and the at least six second tensile members comprises an elastic element and each of which tensile members being attached at one end thereof to the end effector and being attached at the other end thereof to the stationary support; and wherein each tensile member applies a tensile force between the end effector and the stationary support, wherein each one of the at least six tensile members is independently adjustably tensioned by an actuator fixed to the stationary support which acts on the tensile member at a point along its length between the end effector and the elastic element, wherein the actuator acts to change the tension in the part of the tensile member between the end effector and the actuator in order to affect the forces and moments applied to the end effector by the system, wherein the actuator reacts the tensile force it applies to the tensile member against the stationary support, and wherein the tensile force applied by each tensile member to the end effector reacts against the tensile forces applied by the other tensile members via the end effector such that the end effector is maintained in suspension and out of contact with the stationary support by the tensile forces in the tensile members and any other forces applied to the end effector.