Great track with restrictions

What had attracted me to buy this ball track, was the elevator, which transports the balls repeatedly upwards. After building (about 10 hours) I was looking forward so it only zuzschauen the balls in the running. Unfortunately this is not so!
The basic equipment includes 6 balls. If one uses these spheres, it is so that always some balls down the elevator to arrive, while others are transported straight up. This down incoming balls throw most balls in the elevator out again. So they come not only at the top. It is most of the time busy down the falling balls chasing.
This problem could be solved by the manufacturer would offer a "shell" for the elevator.