1) Can I trade in my old Silent Partner Machine?

We'd be happy to help dispose of your old machine but we do not offer trade ins. However, returning customers are eligible for a discount on new machines.

2) I just bought a new machine and really regret not getting the model with more features. What can I do?

Just box up your Silent Partner Machine and we'll have UPS pick it up. You'll be required to pay the difference for your new machine, the return shipping and the shipping of the new machine to you.

3) I've had a machine for years and am looking for a new model. Do you offer any discounts for returning customers?

We love that you were so happy with your first Silent Partner that you are looking to get a new one! We offer a 10% discount on a new machine for repeat buyers. Conditions apply. Call our office for details.

4) Ball machines are a bit out of my budget, is there anywhere I can find discount machines?

Demos and used machines are a great way to buy quality machines at a discounted price. If you are interested in a demo or a used machine, please check our auctions on eBay. We sell demos and blemished machines on eBay under the name "silentpartnerbyauction". All Silent Partner ball machines that we sell on eBay have been checked by us at the factory, and are sold with a 1-year warranty (the satisfaction warranty is not provided for machines sold by auction).

5) I live outside of North America, can I still order a Silent Partner Tennis Ball Machine?

Silent Partner currently ships to addresses in North America. If you wish to place an order internationally please call or email us for more information.

6) How can I track my order?

If you send us an email at sptennis.on.aibn.com with your name we can send you a tracking number so you can follow your Silent Partner's movements right up until it arrives at your doorstep.

7) I want my Silent Partner to last as long as possible. How can I do this?

Check out our Caring For Your Silent Partner page for full instructions from arrival to years later.

8) How long should I expect the battery to last?

The batteries last from 2-5 years depending on use and care over the years.

9) Is my Silent Partner machine only compatible with batteries sold on your site?

Our machines are compatible with any brand of battery, and you can often get them cheaper locally than paying the shipping from our site. Just make sure you get a battery with F2 terminals.

10) Do you offer a discount for multiple machine purchases?

Yes - if you would like to purchase four or more machines, please contact our office.

11) I bought a Silent Partner machine and told all my pals about it. Now they are buying one too! Do you offer any incentives for referrals?

It would be great to send you a free machine cover to thank you for sharing your love of Silent Partner machines! We just need your friend to include your name in the order or send it to us by e-mail after they've placed their order. That way we can look up which machine you have and an address to send it to!

12) Why have prices changed recently?

While we pride ourselves on providing great deals to our beloved customers, prices are subject to fluctuation correlated with our supply chain.

12) Do you have a best price guarantee?

For the last 30 years, we have had the lowest priced quality ball machines on the market, feature for feature. We pride ourselves on providing great deals to our beloved customers, prices are subject to fluctuation correlated with our supply chain.

13) Does Silent Partner have a sponsorship policy?

While we are usually happy to provide a special discount to support junior players, we have to pause this program in 2022. Like so many other small businesses, we hope the effects of COVID are soon behind us and we can return to offering discounts to our customers. 


1) How are balls thrown by ball machines?

All quality tennis ball machines presently available on the market use wheels to throw the ball. Normally there are two wheels that turn in opposite direction (thus the label "counter rotating wheels") with a small space between them. The ball rolls down a chute and is squeezed by the counter rotating wheels which then eject it. The situation is similar to gravel being thrown from under a spinning tire, though in the case of the tire only one wheel is responsible for the "throwing".

2) Do machines with a tube that makes them look like a canon work the same way as machines that use counter rotating wheels for ejecting balls?

No, machines that look like a canon work by air pressure. Pressure is usually supplied to a drum by a vacuum cleaner motor. A ball is lodged at the throat of the tube and is retained by a collar that is slightly smaller in diameter than the ball. When pressure builds sufficiently to push the ball through the collar, the ball is ejected. Because these machines work on air pressure, they are called "pneumatic".

3) Is there any other way for a tennis ball machine to throw balls?

Yes, some machine use a "hammer" to strike the ball, and various spring loaded designs have also been developed. The performance of such machines is so limited that they are not discussed further here.

4) What's better: Counter rotating wheels or pneumatic pressure?

Today no machine costing more than about $700 works on the pneumatic principle. All better machines use counter rotating wheels. There are a number of reasons for this. Pneumatic machines are noisy and do not provide the high level of performance achieved by the better wheel driven machines. Pneumatic machines also require a lot of electrical current and cannot, therefore, be adapted to battery power. The only advantage of pneumatic machines used to be their low cost. Today they are a dying breed.

5) How does a machine put spin on the ball?

Wheel driven machines put spin on the ball by varying the relative speed of the upper and lower wheel. When the upper wheel turns faster than the lower wheel, the ball is ejected with topspin. When the lower wheel spins faster than the upper wheel, the ball is ejected with backspin. Of course, when both wheels turn at the same speed, the machine throws a flat ball. Pneumatic machines use friction in the canon tube or just outside the tube to impart spin. When the bottom of an ejected ball is rubbed as it exists the machine, the ball acquires topspin, and vice versa.

6) Can all machines put spin on the ball?

No, some wheel driven machines do not have spin capabilities. This is usually because the wheels are arranged in a horizontal plane rather than a vertical plane. By changing the relative speed of the wheels in a horizontal wheel machine, one could achieve side spin but no topspin or backspin. Because side spin is not an important element of tennis, manufacturers of horizontal wheel machines do not usually provide a spin adjustment.

7) What is an oscillator?

An oscillator is a mechanism that allows the machine to throw balls in different locations on the court. The most common type of oscillator, known as a random oscillator, causes the machine to sweep the court from side to side repeatedly much like an air fan sweeps a room. Balls are thrown in different and somewhat unexpected locations to simulate play with an opponent.

8) What is an adaptive all-court oscillator?

Some more advanced tennis ball machines provide for vertical oscillation as well as for horizontal oscillation. Vertical oscillation is achieved by varying the angle of elevation - the higher the ball is thrown, the deeper in the court it lands. Some brands of machines achieve vertical oscillation with a mechanical cam that varies the angle of elevation within a fixed range. The ball must be thrown within a narrow range of speed and spin or it will hit the net or fall beyond the baseline. The adaptive all-court oscillation of the Silent Partner Quest and Smart computes an appropriate vertical range to suit the speed and spin selected by the user. The benefits of this adaptive approach are particularly dramatic at high speed and topspin, where the all-court feature provides a pro-level challenge.

9) What is Select-A-Drill?

Select-A-Drill is the name given by Silent Partner to the ability of an advanced machine such as the Smart, to memorize and replay sequences of shot locations. The user can enter a sequence of shots, and then practice the drill over and over. Because the user also selects the speed, spin and feed interval for the drill, a near infinite number of programs can be created to challenge all levels of players.

10) What are Match Play presets?

Play simulation involves programs that simulate play with an oponnent. The computer of the Smart will provide preset speed, spin and ball interval and will simulate actual match rallies with breaks between points. The user can override the preset speed, spin and ball interval rates to suit their own level of ability.

11) What kind of batteries are used in battery powered ball machines?

The batteries used in portable ball machines are sealed and do not leak even when used upside down. The batteries are not motorcycle or car batteries, nor are they "gel cells". The batteries are known as "sealed lead-acid" batteries. Batteries are rated by the number of Amp/hour reserve charge they carry. All Silent Partner ball machines except the LITE use a 21 Amp/hour battery. The LITE has a 9 Amp/hour battery. Unlike certain types of batteries that have a "memory" and that need to be discharged completely before being recharged, lead acid batteries do not have a memory and can be recharged from any state of discharge.

12) How are batteries recharged?

Battery powered ball machines are usually supplied with a battery charger that plugs into a household outlet and that connects to the control panel of the machine. Because the batteries in ball machines are sealed, they must not be charged very quickly. This is why charging time for a dead battery is usually about 10 hours. Faster charging can reduce the life of the battery, although occasional fast charging on an emergency basis will not damage a battery.

13) What is an AC-powered machine?

An AC-powered machine is a machine that can only run on household current (120 volts in North America, 220 volts in most other countries). Such machines do not contain batteries and can only be used when an electrical outlet is available. Owners of private courts and clubs often prefer AC-powered machines because they can be used indefinitely without worrying about batteries running out. Silent Partner machines that are built to run on AC current cost a little more than their battery-powered counterparts and offer similar performance. The AC converter is housed inside the machine, and the machine remains completely portable and can be carried in the trunk of a car.

14) What is an AC-DC machine?

An AC-DC machine contains batteries but is built to also receive an adapter for use with household current. In the case of Silent Partner machines the adapter consists of a convenient hand-carried unit that is separate from the machine. The machine can run on its internal batteries or on the AC adapter. The AC adapter plugs into a normal AC outlet at one end and into the machine at the other. The AC-DC option is desirable in cases where the availability of an AC outlet is not certain, but can be anticipated in some situations or in the future. Silent Partner machines that are equipped with the AC-DC option are just as portable as battery-powered models.

15) Will my machine work outside of continental North America?

Our machines’ electrical components are designed for use in continental North America only.