these machines are equipped either with rosa system vii cnc (siemens sinumerik 840 di) control-unit or a nc system vi (siemens sinumerik 840 di) control-unit. the wheel-head has an interchangeable cartridge. it is built o......these machines are equipped either with rosa system vii cnc (siemens sinumerik 840 di) control-unit or a nc system vi (siemens sinumerik 840 di) control-unit. the wheel-head has an interchangeable cartridge. it is built of ground and hardened case-steel and runs on a quadruple gang and a pair of opposed angular precision bearings. inside of the spindle, there is an automatic system for changing the grinding wheel having a clamping device and a balancing device for the wheel.