这个发条需要正反两个方向装，这样可以使运动轨迹居中，可以当作弹弓使用，不需要担心损坏，圆头可以起到限位作用。

两个发条同向安装：

1，逆时针旋转一圈 ，用小的棍子卡住，让你的朋友帮忙把棍子取下来，你将会收获朋友的友谊。

2，顺时针一直旋转，你将会听见悦耳的声音。

感谢您的支持！

This spring needs to be installed in two directions, so that the movement trajectory can be centered, can be used as a slingshot, do not need to worry about damage, the round head can play a limiting role.

Two springs are installed in the same direction:

1, turn a circle counterclockwise, stick with a small stick, let your friend help take down the stick, you will reap the friendship of friends.

2, turn clockwise all the way, you will hear a pleasant sound.

Thank you for your support!