Abstract: A motion generating system for simulator includes a multi-tier assembly of jacks. The multi-tier jacks permit a platform and equipment on the platform to move freely and safely in six degrees of freedom and to a maximum extent permitted by the mechanical properties of the jacks and joints. In the preferred embodiment of the present invention, a two-tier assembly of jacks connects the floor and the platform of a simulator for extending a maximum range in movement of platform and equipment on the platform.