The frame is processed by large NC with high precision and long service life; it uses RV reducer with high precision and strong overload resistance; the wire entry hole at the driven end has a diameter of 80, which can directly pass the aviation plug; the horizontal position of the foot adjustment and the position of the expansion screw are separated, which is convenient for installation and the base is not easy to deform; the turntable has reserved counterweight installation holes and good scalability.