MG996R Servo · Star Horn

A high-torque, metal-gear positional RC servo that delivers up to 11 kg·cm of stall torque under standard 50Hz PWM control.

Try it in the simulator View datasheet

MG996R Servo · Star Horn: High-torque servo variant

What is the MG996R Servo · Star Horn?

The MG996R is a high-torque analog hobby servo from TowerPro, widely treated as an upgraded MG995 with all-metal gears and a dual ball-bearing output shaft for better durability under load. It is a positional servo with roughly 180 degrees of travel, and this variant ships with a four-arm star horn for attaching linkages, arms, and brackets.

Control follows the standard RC servo convention: a 50Hz signal (20ms period) where the pulse width sets the target angle, with about 1ms near one extreme, 1.5ms at center, and 2ms near the other extreme. Internal control electronics and a feedback potentiometer hold the commanded position. It produces roughly 9.4 kg·cm of stall torque at 4.8V and 11 kg·cm at 6V, moving 60 degrees in about 0.17s at 4.8V and 0.14s at 6V, with a 5 microsecond dead band.

It runs on a 4.8-7.2V supply (6V nominal per the verified specs) and the SIG line accepts the logic-level control pulse. Because it is a geared actuator, current draw rises sharply with mechanical load and can spike toward 2.5A at 6V under stall. The unit measures 40.7 x 42.9 x 19.7mm and weighs about 55g.

MG996R Servo · Star Horn pinout

Pin	Function	Type
`VCC` VCC (4.8-7.2V)	Power	Power in
`GND` GND	Power	Power in
`SIG` PWM Signal	PWM servo control pulse	Digital input

Specifications

Operating voltage: 6 V (max 7.2 V)
Interface: GPIO timing (Trigger / Echo)
Dimensions: 40.7 × 42.9 × 19.7 mm

Verified from the Tinkered component library · TowerPro.

Circuit requirements

Power the servo from a dedicated 4.8-7.2V supply rather than the Arduino onboard 5V regulator; stall current can approach 2.5A at 6V, which will brown out or reset the board.
Tie the servo supply ground to the controller ground so the PWM pulse shares a common reference.
The SIG line only needs the control pulse (50Hz, 1-2ms wide); the signal current is small, so it can connect directly to a digital output pin.
Add a bulk capacitor (for example 470-1000uF) across the servo VCC and GND to absorb the inrush when the motor starts moving.
Do not exceed the 7.2V maximum on VCC; the internal electronics and motor are rated for the 4.8-7.2V window.

Board compatibility

The MG996R Servo · Star Horn connects to any of the microcontrollers supported in Tinkered. Mind the 6 V logic level on 3.3 V boards.

Common MG996R Servo · Star Horn mistakes

Powering it from the Arduino 5V pin

The MG996R can draw close to 2.5A at stall, far beyond what a USB-powered board's regulator supplies. Running it off the 5V pin causes voltage sag, glitching, and repeated resets. Use a separate supply sized for the load.

Forgetting the common ground

When the servo runs on its own supply, the control pulse has no valid reference unless that supply's ground is also connected to the controller ground. Without it the servo jitters or ignores commands.

Expecting continuous rotation

This is a positional 180 degree servo, not a continuous-rotation servo. Sending pulse widths does not spin it endlessly; it seeks and holds an angle. Only a physically modified unit rotates continuously.

Commanding angles past the mechanical stops

Pushing pulse widths beyond the usable 1-2ms range drives the servo into its end stops, where it buzzes, stalls, and strains the gears while drawing peak current. Keep commanded pulses within the rated travel.

Skipping a decoupling capacitor

The sudden current surge when the motor starts moving pulls the rail down and can corrupt nearby logic. Omitting a bulk capacitor across the servo supply leads to intermittent resets and erratic motion, especially with multiple servos.

MG996R Servo · Star Horn datasheet

Official MG996R Servo · Star Horn datasheetTowerPro

Popular MG996R Servo · Star Horn projects

Robotic arm joints

Its high torque and metal gears make it a common choice for the shoulder and elbow joints of small robotic arms that lift real payloads.

Pan-tilt camera or sensor mount

Two MG996R servos on a bracket give steady pan and tilt control for cameras, ultrasonic sensors, or solar trackers.

RC steering and throttle linkages

The star horn and strong output shaft suit steering and throttle actuation in RC cars and boats where torque matters.

Animatronics and moving props

Positional control and holding torque let it drive jaws, wings, and other animatronic mechanisms on cue.

Dispensers and latch mechanisms

Its torque is enough to actuate simple door latches, gates, and dispensing arms in automation projects.

Build with the MG996R Servo · Star Horn.

Drop the MG996R Servo · Star Horn into a circuit, write firmware, and simulate it in your browser, then deploy to real hardware. All in one editable Tinkered project.

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