In the near future machining of special materials or substrates and e.g. semiconductor lithography will require an ultra clean gaseous or vacuum atmosphere. Large workpieces or substrates will need to be positioned at high speed (e.g. 20 m/s) with high acceleration (e.g. 2 g) and high accuracy (e.g. 5 nm). For industrial heavy duty applications large, differentially pumped, motion feedthrough designs have been developed. Feedthrough designs that allow for long stroke (e.g. 0.5 m) X, Y, Z, phi, theta positioning with high accuracy and for vacuum applications in the 10e-6 to 10e-8 mbar range will be presented.