4: The shuttle is not installed properly.

Eliminate the method:

A: shuttle library shuttle in front of the front rail should be parallel and maintain the interval of 0.8 ~ 1.6mm.

B: The shuttle should be close to the shuttle, and in the shuttle only to leave a shuttle when the natural light can still fall. At present, many factories generally use 5.5 ~ 6mm thick hard rubber, instead of copper and nylon drag film.

C: Basketball feet should be parallel with the bottom of the shuttle box, and higher than 1.6mm.