（1）Fix the left and right cradles to the door-body horizontally
（2）Suspend door-body from guide rail，if the door-body glides to the left or the right，the cradle is not horizontal. If that, you should off-load the door-body and adjust the guide rail horizontally
（3）When has suspended the door-body from the guide rail，close and open the door with hand lightly.
（4）The active-door should be installed orthogonally. If the gap between active-door and fixed door is not accordant，please loosen the cradle device nut or ground wheel nut and adjust it. The gap size should conform the stipulation。When the active-door is aslant as the following chart make it orthogonal by adjusting the nut of cradle A
（5）Make sure that there is no friction phenomenon between active-door and static as guide rail，cover plate，fixed door，ground and so on
Notice：Please do not permit grease on guide rail, otherwise the wheel on the cradle device will slip and the door-body will jitter，then affect operation