These machines are equipped with a ROSA SYSTEM VII CNC (Siemens Sinumerik 840 Di) control unit. The lower part of the vertical slide houses the rotary table unit (double toothed HIRTH crown) driven by an AC brushless moto......These machines are equipped with a ROSA SYSTEM VII CNC (Siemens Sinumerik 840 Di) control unit. The lower part of the vertical slide houses the rotary table unit (double toothed HIRTH crown) driven by an AC brushless motor. The electro-spindle, which is mounted on the rotary table, can be swivelled by +/-110° with a repetition accuracy of 2 angular seconds. The rotation is obtained by means of a special bevel/worm-gear pair with adjustment of the play to minimum values. An encoder, which is positioned on the same axis as the drive-screw, enables the position control.