Also called virtual shafts machine tool,it is constituted by 6 free space parallel structure, i.e.link the fixed platform with moving platform with 6 telescopic rods with spherical hinges or hookes.When the length of 6 rods are changed,you can get the moving platform in different positions. The electric spindle are equipped on the moving platform.The 6 telescopic rods are composed by ball screws and ball splines....