Principles of automatic roulette ball ejection

One of the key characteristics by which we distinguish automated roulette wheels of different manufacturers is the applied principle of ball ejection.

Since the appearance of automated roulette, it has been experimented with different ball ejection concepts, including spring-mechanical ones similar to those we see in pinball machines. However, over time, two main systems remained in wider use, both of which use air pressure to eject the ball, namely compressor and fan systems.


Compressor ball ejection system

The movement of the ball is controlled by compressed air that is ejected in a controlled manner from several subtly placed nozzles. The advantage of this system is that the ball always remains in the player’s sight, which to a certain extent enhances the somewhat shorter game cycle. The key difference between this principle and the original game is the continuous management of the ball’s motion. Such a feature in the eyes of the player represents a potential disadvantage because the ball’s movement is clearly unnatural and raises the suspicion of active manipulation of the outcome of the game. Another disadvantage lies in the sophistication of the system, which due to its complexity is more susceptible to breakdowns and, above all, the need for periodic maintenance of the air compressor, and on top of that, potential challenges related to the placement and noise of the compressor.


Fan ejection system

After reading the winning number, the ball is being “swallowed”, i.e. it is taken by gravity to the starting block located inside the device, from where it is then thrown out onto the balltrack through a spirally formed tube with the help of a centrifugal motor – a fan. Once dropped onto the balltrack, the ball continues to move freely on its way to the final winning number. In this case, the ball is normally out of the player’s sight for a few seconds, although by adding a second ball to the system, this can be avoided in such a way that the second ball flies out in sync with the fall down of the first.



With a compressor ejection system, the ball is normally in the player’s sight all the time and is usually ejected in a different direction each time. But on the other hand, the continuously controlled movement of the ball arouses suspicion among the players about the manipulation of the result, and the sophisticated system, which requires periodic maintenance and frequently relocated compressor station, complicates the operators’ job.

Automatic roulette cylinders with a fan ball ejection system may or may not have a bilateral ball ejection function – because of the ball supply pipe they are often slightly larger in diameter, and in the case of using only one ball, it is not in the player’s sight all the time. However, the movement of the ball is free and natural, the system is robust in its conceptual simplicity, and does not require displaced elements and periodic maintenance.