Free Shipping on orders over 99*. Learn More
  $26.99  $18.99
Add to Cart
Add to Wish List
In stock online

Ideally priced mini servo offers high speed, and dual ball bearing supported output shaft for a variety of aircraft and surface applications.


Image for S25 Mini Servo from HorizonHobby
+ / - Hover over image to Zoom
S25 Mini Servo S25 Mini Servo
  • Overview
  • Specs
  • Reviews
  • Parts & Accessories
  • Manuals & Support


  • All mounting hardware included.
  • 1-year limited warranty
  • Servos feature a universal connector compatible with all major radio brands.


Expertly engineered Onyx servos deliver the speed, torque and precision needed for optimal results in a wide variety of applications. Onyx servo options allow you to match your needs to the letter. Select from analog or digital styles, plastic or metal gears, and options with ball bearings and coreless motors. Onyx servos are solid buys in long-lasting performance and a pleasant surprise in value. Onyx servos are a simple way to enjoy savings without sacrificing performance. All Onyx servos are protected by a 1-year limited warranty. All also include a universal connector and mounting hardware.

What's in the Box?
  • Onyx S25 Mini Digital High Speed Servo
  • 0.75 in (19mm) Single Arm Horn
  • 0.83 in (21mm) Round Horn
  • 1.5 in (39mm) Double Arm Horn
  • 1.2 in (31.5mm) diameter 6-Point Horn
  • 1.5 in (37.8mm) diameter 4-Point Horn
  • Four each Grommets, Eyelets and Mounting Screws
  • 2.5mm Servo Horn Screw
Bushing Or Bearing: Bushing
Gear Material: Plastic
Height: 1.14 in (29mm)
Length: 1.4 in (36 mm)
Programmable: No
Servo Operating Voltage: 4.8 - 6.0V
Servo Size Category: Mini and Micro
Speed: 0.15 sec/60 deg @ 4.8V, 0.12 sec/60 deg @ 6.0V
Spline Count: 25 Teeth
Torque: 84 oz-in (6.1 kg-cm) @ 4.8V; 91 oz-in (6.6 kg-cm) @ 6.0V
Weight: 0.88 oz (25 g)
Width: 0.59 in (15 mm)

Optional Accessories

In Stock
In Stock
In Stock
In Stock
In Stock
In Stock
$7.99  $5.99
In Stock
$12.99  $12.34
In Stock
In Stock



What's the difference between digital and analog servos?

Digital and analog servos have very similar construction and components. They both use the same type of motors, gears, cases, and have a potentiometer. A digital servo is different in the way it processes the incoming signal and converts that signal into servo movement. 

An analog servo when it receives a command to move, takes that signal and sends pulses to the servo motor at about 50 cycles per second, which in turn moves the motor to its required position determined by the potentiometer.

A digital servo has a micro-processor that receives the signal and then adjusts the pulse length and amount of power to the servo motor to achieve optimum servo performance and precision. A digital servo sends these pulses to the motor at a much higher frequency which is around 300 cycles per second. This helps eliminate deadband, provides a faster response to the servo motor, smoother motor movement, and has higher resolution and holding power than an analog servo.

There are some disadvantages to digital servos, but the disadvantages are not in any way close to out weighing the advantages. A digital servo will have a higher power consumption (Around 10 to 15 mAh per servo at idle) than an analog servo due to its higher pulse frequency, so larger capacity battery packs are recommended. Digital servos also are more expensive than analog servos which can get very costly in applications that require many servos.

What grease should I use on my servo gear train?

For JR servos we recommend Tamiya ceramic grease (TAM87025).

Why doesn't my servo center properly?

There are several scenarios which may attribute to this problem.

1. The servo arm fit on the output spline may be loose.

2. There may be slop or wear in the gear train.

3. There may be slop or binding in the linkages.

4. You may have a faulty servo saver.

5 The push rods may be too flexible.

6. Improperly mounted servo (screws too tight, mounting rail too tight against the servo)

7.Faulty extention, damaged lead or dirty connector.

8. Worn or dirty pot.

Product Support Tips

Product Support

Technical questions about this Onyx product should be directed to Horizon Hobby's Product Support Department:

Horizon Hobby, LLC.
ATTN: Product Support

2904 Research Road
Champaign, IL 61822

To Contact Product Support please email us at

Sales Support

If you would like to purchase this product, please go to the Store Locator or contact the Horizon Hobby Consumer Sales Department:

Horizon Hobby, LLC.
ATTN: Consumer Sales

2904 Research Road
Champaign, IL 61822