Problem (see video) :
Solution 1 : The photocell is too far (width) compared to the shuttlecok, so you have to push the photocell in direction to the robot.
Solution 2 : The shuttlecock is too high compared to the photocell, so you have to downside the shuttlecock.
If Solution 1 or Solution 2 doesn’t fix the problem, follow the Solution below :
Solution 3 : thighten the screw as seen on the photos below
Solution 4 : Drill four holes in the clamps of the robot and add 4 screw.
Problem : The chain (see photo) who brings the shuttlecocks is broken (see video)
Solution : If you have a quick link(see image 3 below), you only have to disassemble the robot, you need to access to the chain and fix it (see video). If you don't just ask to us !