The majority of tennis ball launcher machines on the market operate using counter-rotating wheels. When the machine is turned on an electric fan draws in outside air which is then pushed into the canister. To protect the fan motor from debris the air passes through a slab of foam as well as a screen barrier. A tennis ball launcher represents a solid investment for anyone looking to improve their game, whether they have access to professional coaching or not. With a tennis ball machine you can take to the courts and practice your strokes anytime you feel like and for a long as you like.

A normal tennis ball launcher would have a ball bucket or what is called the hopper, where you are able to put at least some tennis balls at one time; a built in oscillator, which is an electronic device that produce alternating current, commonly employing tuned circuits and amplifying components such as thermionic vacuum tubes; and a barrel, where tennis balls are shot out. A tennis ball launcher usually fire tennis balls non-stop as long as it has electricity and steady supply of balls.  To be able to this, it uses pressure.

When a Tennis Ball Launcher is turned on, an electric fan inside the machine pulls air from outside into the canister. The air flows through a filter, which is a piece of foam and a protective screen, which guards the fan motor from fragments or debris that could damage the motor.

Without any balls in the bucket (hopper), air just flows upward through the hopper and out through the barrel. But when tennis balls are added, things get fascinating. Inside the hopper is a rotor, when balls are added to the hopper, an electric motor turns the rotor, and as the rotor turns, it rolls the balls through a whole one at a time.  A plastic tube that runs through the canister is where each ball falls.  This tube connects the hopper to the barrel and the gap in the middle of the tube allows air from the chamber to flow into it.

Inside the tube is a soft rubbery ring called the detent, the ball rolls through the tube until it reaches the detent, the detent then holds the ball in place so that the ball seals off the end of the tube closest to the barrel.  When this happens, it causes the air from the canister to flow up through the hopper, forcing a plastic flap to cover the entrance of the tube, when both ends of the tube is blocked, air pressure inside starts to build up. Once air pressure behind the ball surmounts the resistance from the detent, the ball flies down the barrel and is launched into the air.  After the ball is launched, the pressure is removed in the tube so that the flap at the entrance falls back down and another ball falls into the tube, then the process starts again.

Tennis ball launchers are used by tennis players to practice and improve their skills, we simply see them as machines that shoot balls, now we have an idea of how it works and what keeps the balls coming non-stop.