The FS milling machine has been developed like a product with a great rigidity in his structure, being a heavy machine over dimensioned, to guarantee the best possible answer in a limit working condition. The movement of the machine is by linear guideways, that slide on roller blocks providing two basic improvement like a better positioning and repeatability of 0,005 mm , by the elimination of the classic friction of the prismatid guideway (the çSlip-Stick effect), and bigtger working feeds, that allow to optimise all machining time without maintenance.