Review of the Slinger Bag: your very own portable tennis ball launcher

Tennis has been a pioneer in bringing sports into the digital age. Smart technology meant to boost your skill level is now freely accessible to both professional and casual players. This covers everything from sensors that attach to your racquet and track shots to robots that hoover up tennis balls to save you time and effort.

Just when we thought we’d seen everything, another clever device appears to prove us wrong. You no longer need to practise with live tennis players!

The Slinger Bag is a high-tech portable tennis ball launcher in the shape of a large tennis bag. The product has been in the works for a few years and was inspired by a successful Kickstarter effort (and a later Indiegogo campaign) that raised over $1 million. After a few manufacturing delays, the product is now available for purchase by anyone.

Those in the United States can purchase the Slinger Bag tennis ball machine by following this link. The device is also available in the United Kingdom and a few other countries.

“We had this crazy concept that rapidly became a core objective for us: that everyone should be able to buy a tennis ball launcher,” said the company that created the gadget.

So they started working.

The bag can launch balls at you at rates of up to 45 miles per hour. You regulate the pace, and the device may be programmed to launch shots at various angles and elevations.

The ball launcher has piqued the imagination of many aspiring amateurs and hobbyists. Even famed tennis instructor Nick Bollettieri and all-time greats the Bryan Brothers have endorsed it.

Coronavirus lockdown procedures in the United Kingdom have been lifted somewhat. This freed me up to visit the tennis courts with my new tennis partner. Here’s how I felt about it after a month of use.

The Design Slinger appears to be a cross between a large tennis bag and a nice-looking suitcase. The whole thing feels well-made and well constructed. It weighs roughly 33 pounds (without tennis balls), but it has a handle and two robust wheels on the bottom, so you can use it as a trolley. I wouldn’t recommend carrying it on your shoulders, but there is a shoulder strap.

The ball launcher is lightweight and portable. It is higher than the competition, but it is also lighter. It’s difficult to locate a good tennis ball machine that weighs less than 40 pounds, and its larger equivalents can weigh up to 99 pounds. Not to mention that they do not appear to be as nice! There’s no way to tell if the Slinger Bag is a tennis ball launcher when it’s “zipped up.”

Review of the Slinger Bag: your own personal tennis ball launcher

Tennis racquets, water bottles, towels, and other items can be stored in it. There are several practical compartments, including one at the top of the bag for larger goods. There is another pocket on the left side and another on the right. The latter even includes a USB port for charging your smartphone while you practise. That’s a nice touch.

You may also buy a little unit that attaches to the handlebars to hold your smartphone. You can film yourself practicing this way.

The capacity of the ball

The Hopper Pocket is located just beneath the main storage area. This is where the tennis balls are stored. The feeder plate and mechanism that draws the balls down into the shute and slings them out are located beneath. Although the maximum capacity is 144 tennis balls, the company recommends filling the hopper with 72 tennis balls for optimal performance (when the hopper is open).

Your own personal tennis ball launcher, the Hopper Pocket, holds up to 144 tennis balls.

During use, I discovered 72 to be a pleasant number. It provides a fun mix of practice and time spent gathering the balls. What I didn’t expect was that picking up the balls would be such a physical challenge! Slinger also sells a telescopic ball tube to make things easier. This fits neatly over the bag and will help a little. However, I discovered that some of the balls do not simply slide out of the tube, which can be aggravating.

The battery and control panel

The unit’s brains are located underneath. When you unzip the front cover, you’ll notice the control panel. The space behind the battery is on the left, and there are a couple of dials on the right.

The top dial adjusts the pace of the balls from beginner to advanced. The top speed is approximately 45 mph (72.5 kph). The settings are the same on the bottom dial. This one regulates the feed rate, or how frequently the balls are hurled at you. This can range between 2 and 10 seconds.

On a full charge, the battery will provide approximately 5 hours of play time, which is pretty adequate. Typically, I would take it to the court for a 2-hour session and then plug it into an electrical outlet when I got home. It would then recharge in approximately an hour or two, while charging a battery from zero to maximum capacity can take up to 6 hours.

When the battery is fully charged, the power is decreased to a single ‘pulse’ to extend its life. To ensure optimal battery performance, the business recommends plugging Slinger into an electrical outlet at least once a month.

Review of the Slinger Bag: your very own personal tennis ball launcher

The Elevation Bar

Another zipper can be found on the bottom right side of Slinger. When you open this, you’ll notice a small handle that allows you to regulate the trajectory of the ball. This provides a ball elevation range of 10 to 40 degrees. I usually set it to 10 or 15, unless I was practicing overheads or serves, in which case I went with 40.


An oscillator is also included with the Slinger Bag ball machine. This is available independently or as part of a package. You’re supposed to put it under the ball launcher. This shifts the unit from left to right, giving you a more intense workout.

If you buy Slinger, I recommend you include the oscillator because it makes a great difference. The oscillation does not strike short or deep balls at random, but it will force you to return balls shot in all directions of the court. This allows you to practise your backhands and forehands, as well as your footwork.

Review of the Slinger Bag: your very own portable tennis ball launcher

Configuring the Slinger Oscillator (before/after)

Control through remote

Finally, you get a small remote with minimal start/stop capability. It has two different buttons, one for the launcher and one for the oscillator. Both of these work effectively, even if you’re at the opposite end of the court.

The inclusion of a remote is actually a very wise decision on the part of the firm. When you think about it, if something is ready to start flinging balls at you at rates of up to 45 mph, you should not be standing right in front of it!

How to Apply

On a court, the Slinger ball machine may be programmed to run in one minute. I usually set it right inside the baseline because it provides a decent depth of shot. Having said that, Slinger is readily relocated on the court, so you can experiment with varying court positioning to determine what works best for you. You can play around with the location, speed, angle, and frequency of the balls.

Before we go any further, consider this: I’ve been playing tennis once or twice a week for nearly ten years. As a result, I consider myself an intermediate player rather than a beginner or advanced player.

Groundstrokes, volleys, and serves

Switch on the ball machine after you’ve positioned it by pushing the physical button on the control panel. When Slinger Bag turns on, you’ll hear a beep. This does not initiate the launch mechanism; it simply turns it on.

The Slinger can be used with or without the oscillator. To use the oscillator, first lift Slinger and place it on the plastic oscillating unit. This is then plugged into the control panel for power. After a few seconds, you’ll notice the oscillator (along with the ball machine) moving from left to right.

In terms of settings, I usually use the high-intermediate level for speed and the low-intermediate level for ball feed while utilizing the ball launcher. This propels the ball pretty far into the court, requiring me to return it from near the baseline. I discovered that the setting closely resembles the level of player I usually encounter in match play.

In terms of frequency, the above-mentioned feed setting indicates a ball would come my way every 4-5 seconds. This was very comfortable for me because it gave me ample time to prepare and focus on the next shot.

Of course, this is for groundstrokes. If I wanted to practice putting away balls, I would choose an angle of roughly 10 degrees, occasionally 15 degrees. Volleys would also get around 10% of my attention.

After adjusting the speed, feed, and angle, use the remote to activate the ball launcher. A beep will be heard, followed by another a few seconds later. The launch mechanism will begin after the second beep.

One thing to note is that the rotation of the balls cannot be controlled. Every ball has a high spin rate. This has the effect of speeding up the ball when it bounces on the court, giving you less time to respond. This makes a difference since the balls are more difficult to return.

Because the effect is more obvious at higher speeds, changing the ball speed is one approach to managing the amount of topspin. Altering the elevation angle to obtain the ideal launch sequence for your game is another option.

Because of the top spin, you must be really focused, stride into the ball, and smash it early. which you should do anyhow, so it’s good practice.

However, it is less beneficial for volleys because all you get are dipping volleys, which can be tough to manage. Having said that, those types of shots do occur during match play, so they are useful for practice. However, it is ideal for groundstrokes, overheads, and other shots.

I would occasionally increase the speed to the maximum available level of 45 mph. As previously said, the higher the speed, the greater the top spin impact, making these balls incredibly difficult. Beginners would struggle in this setting, but intermediates and advanced players would benefit from it. It’s not quite Rafa Nadal level, but it’s close.

My only concern was that the device would be too noisy. After all, I don’t want to draw attention to myself or bother other players on the surrounding courts. And I’m happy to say that it isn’t. There is a little whirring sound at the high intermediate level, although it is hardly audible from the opposite end of the court. The top setting does make it a little louder.

This machine is quite versatile. Because you can vary the angle of the ball, choosing 40 degrees allows you to practice overheads. You will need to concentrate once more because the spin of the ball makes it more difficult than it appears at first glance.

Finally, the Ball Boy mode is worth highlighting. Simply set the feed at a slower pace, drop the speed to the minimum, and increase the angle to the maximum of 40 degrees. Slinger will lob balls in your direction every few seconds if you place them a few meters away from you, allowing you to practise your serves.

I haven’t mentioned tennis balls much. Slinger is available with Trinity Wilson balls, which I found to perform slightly better than other brands. They have a special plaster material that increases their longevity. According to Wilson, Trinity Balls last four times longer than other tennis balls.

During practise, I used a mix of 72 Trinity Wilson tennis balls and 8–10 vintage tennis balls from various brands. This added some diversity because the used tennis balls didn’t fly out as much, forcing me to run forward at times.

A few words about ball jams are also needed. After using it for a month, I’d say a ball jam happens about once every 300 balls. This is set at the intermediate level. It happens more frequently in advanced mode. These figures are normal for even the most premium brands. Simply turn off Slinger and remove the ball if a ball jam occurs. It’s a five-second task.

In conclusion,

Probably the most pressing issue on your mind is, “Is the Slinger Bag any good?”

As part of the Gadgets & Wearables category, when it comes to high-tech tennis equipment, I’ve tried everything. Smart tennis racquets, swing tracking bracelets, smart racquet dampeners, and even a GoPro-like device that identifies whether a ball has landed within or outside the court in real time are all available. I’ve tried everything. Slinger, in my opinion, is the most practical of the bunch because it has the most potential to improve your game.

Drills and repetitions are required to increase your skill level. Without it, you will become stagnant. And practice and court time are essential. Slinger gives you a dependable practice partner who is never late or grumpy. You could even compare it to a tennis instructor.

The ball launcher works well, looks amazing, can hold a lot of tennis balls, and can be customized to your level of play. In terms of ball speed and spin, I believe it will satisfy the majority of players. I discovered that the oscillator makes a significant difference since it forces you to return balls shot in all directions.

Is Slinger flawless? 

No I would have appreciated it if you could have had greater control over the ball’s spin. The product is enormous, yet it is quite portable and has excellent storage capacities – not just for balls, but also for racquets, water bottles, and other items.

Tennis ball machines are one of the most efficient and rapid methods of improving your game. However, most of these are expensive. The Slinger Bag is meant to allow practically anyone to possess a competent tennis ball launcher at a more affordable price. Most importantly, it does not resemble a tennis ball launcher!

This link will take you to a page where you can buy the Slinger Bag. You can get it in the UK here.

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