... HIWIN guide rail High quality mini cnc milling machine for metal(7STC-6060A) Product features: With 600mm* ... can check the real-time trajectory, plus or minus Z-axis depth in real-time, and ... and the balls rolling fast when the machine working. For the coefficient of rolling friction is smaller, ... of all kinds of CNC engraving machines, suitable for various of materials, such as: wood, stone, ...