There's quite a lot of wiggle room: you have to move the device quite far away, or move quite far off the central axis, before the 3D effect is lost.
保留了相当大的摆动空间︰除非双眼距离游戏机很远，或偏离了中轴线很远，才会失去3D效果。
2
By taking advantage of rotating centrifugal force and the supporting effect of eccentric short drill collar, we cut off the axis inclination of bit, and avoid well inclination.
Butterfly valve is closed parts (valve flap or disc for disc), around the valve axis of rotation to achieve the open and close a valve, in the pipeline mainly as shut off and throttling effect.