# The Maker's Guide to Servos: Torque, Speed, and Control Compared

Compare hobby and industrial servos by torque, rotation range, and control type (PWM, digital, continuous) to pick the right motor for robotics, animatronics, and RC projects.

_Updated 2026-05-18 · Reviewed by Marcus Schappi, Co-founder, Little Bird Electronics._

URL: https://littlebirdelectronics.com.au/guides/makers-guide-to-servos

---

Servos are the easiest way to add controlled movement to a maker project: point a camera, steer a robot, flap a wing, open a latch or drive a small wheeled bot without designing a gearbox from scratch. This guide compares hobby micro servos, clutch-protected servos, continuous rotation servos, metal-gear upgrades and serial bus servos for students, robotics hobbyists, educators and prototypers.

We focus on the specs that actually change your build: torque in kg·cm, rotation range, voltage, speed, gear material, control type and how many servos you can safely power and control. We also cover the common trap that catches beginners: the signal wire can come from an Arduino, Raspberry Pi Pico, ESP32 or micro:bit adapter, but the servo power usually needs a separate supply.

## Our picks

- **Micro servo** — Best overall — https://littlebirdelectronics.com.au/products/micro-servo
- **Micro Servo 9g** — Best value — https://littlebirdelectronics.com.au/products/micro-servo-9g
- **9g 300° Clutch Servo** — Best micro servo for wider travel — https://littlebirdelectronics.com.au/products/9g-300-clutch-servo
- **9g 180° Clutch Servo** — Best for student-proof micro mechanisms — https://littlebirdelectronics.com.au/products/9g-180-clutch-servo
- **6Kg 180 Clutch Servo** — Best for tougher mechanisms — https://littlebirdelectronics.com.au/products/6kg-180-deg-clutch-servo
- **2Kg 300° Clutch Servo** — Best for protected long-travel motion — https://littlebirdelectronics.com.au/products/2kg-300-clutch-servo
- **2Kg 180° Clutch Servo** — https://littlebirdelectronics.com.au/products/2kg-180-clutch-servo
- **9g micro servo (1.6kg)** — https://littlebirdelectronics.com.au/products/9g-micro-servo-1-6kg
- **Sub-micro Servo - SG51R** — Best for ultra-compact builds — https://littlebirdelectronics.com.au/products/sub-micro-servo-sg51r
- **Micro Servo 9g - Continuous** — Best for small wheeled robots — https://littlebirdelectronics.com.au/products/micro-servo-9g-continuous
- **2.3KG Serial Bus Servo (6V)** — Best smart servo alternative — https://littlebirdelectronics.com.au/products/2-3kg-serial-bus-servo-6v
- **MG996 Servo 180° Metal Gear** — Best high-torque option — https://littlebirdelectronics.com.au/products/mg996-servo-180-metal-gear
- **Bulk 9 Gram Servo - 10 pack** — Best for classrooms and batch builds — https://littlebirdelectronics.com.au/products/bulk-9-gram-servo-10-pack
- **TowerPro SG90C 360 Degree Micro Servo (1.6Kg)** — https://littlebirdelectronics.com.au/products/towerpro-sg90c-360-degree-micro-servo-1-6kg
- **Micro Servo - MG90S High Torque Metal Gear** — Best metal-gear micro upgrade — https://littlebirdelectronics.com.au/products/micro-servo-mg90s-high-torque-metal-gear
- **Continuous Rotation Servo [FeeTech FS5103R]** — Best for simple continuous-drive mechanisms — https://littlebirdelectronics.com.au/products/continuous-rotation-servo-feetech-fs5103r

---

## Micro servo

_Best overall_

**Price:** $13.04 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/micro-servo

The Adafruit Micro servo is the safe default for a first positional servo project. It is small, beginner-friendly, rotates approximately 180° and works with ordinary servo code, hardware and libraries.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** Approx. 180°
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Best use:** Beginner positional motion
**Pros:**

- Beginner-friendly standard servo control
- Approximate 180° positional movement
- Small size suits pan/tilt and compact mechanisms
- Works with common servo libraries
**Cons:**

- No torque figure supplied in the input
- Not intended for heavy load-bearing joints
---
## Micro Servo 9g

_Best value_

**Price:** $5.36 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/micro-servo-9g

The Little Bird Micro Servo 9g is the budget-friendly workhorse for mechatronics classes, simple robots and lightweight mechanisms. Its listed 1.6 kg·cm torque, 4.8–6.0 V operating range and fast 0.10 sec/60° movement make it a practical first servo.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** Approx. 160° in practice
- **Torque:** 1.6 kg·cm max
- **Operating voltage:** 4.8–6.0 V listed, 3.0–7.2 V stated
- **Speed:** 0.10 sec/60°
**Pros:**

- Low price for repeat builds
- Listed 1.6 kg·cm torque
- Works from common 5–6 V servo supplies
- Standard 3-wire servo connection
**Cons:**

- Practical rotation is around 160° rather than a full 180°
- Micro size limits useful load
---
## 9g 300° Clutch Servo

_Best micro servo for wider travel_

**Price:** $8.46 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/9g-300-clutch-servo

The DFRobot 9g 300° Clutch Servo is useful when a normal micro servo does not sweep far enough. The clutch and electronic protection make it more forgiving in small mechanisms that may be bumped, blocked or back-driven.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 300°
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Protection:** Clutch and electronic overload protection
**Pros:**

- Wide 300° positional travel
- Built-in clutch protection
- Electronic protection cuts power after prolonged blocking
- Compact 9 g class format
**Cons:**

- Torque not specified in the input
- Wider travel may require careful linkage design
---
## 9g 180° Clutch Servo

_Best for student-proof micro mechanisms_

**Price:** $8.46 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/9g-180-clutch-servo

The DFRobot 9g 180° Clutch Servo is a good classroom alternative to a basic micro servo when students may twist horns by hand. It keeps the familiar 180° movement style while adding clutch and electronic protection against common handling mistakes.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 180°
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Protection:** Clutch and electronic overload protection
**Pros:**

- Familiar 180° positional range
- Clutch helps protect against forced movement
- Electronic protection for blocked conditions
- Small enough for compact teaching projects
**Cons:**

- Torque not specified in the input
- Costs more than the cheapest 9 g micro servos
---
## 6Kg 180 Clutch Servo

_Best for tougher mechanisms_

**Price:** $15.85 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/6kg-180-deg-clutch-servo

The DFRobot 6Kg 180 Clutch Servo steps up the torque while keeping damage-tolerant clutch behaviour. It is a sensible choice for robotics and mechanical projects where the servo may see external force or short stalls.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 180°
- **Torque:** 6 kg·cm
- **Operating voltage:** Not specified
- **Protection:** Clutch and electronic overload protection
**Pros:**

- Listed 6 kg·cm torque
- 180° positional movement
- Built-in clutch protection
- Electronic protection for blocked output
**Cons:**

- Operating voltage not specified in the input
- Still needs proper external power under load
---
## 2Kg 300° Clutch Servo

_Best for protected long-travel motion_

**Price:** $10.49 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/2kg-300-clutch-servo

The DFRobot 2Kg 300° Clutch Servo balances useful torque, wide travel and protection. It suits gauges, scanning sensors and animatronic linkages where you want more than 180° of movement without moving to a continuous rotation servo.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 300°
- **Torque:** 2 kg·cm
- **Operating voltage:** Not specified
- **Protection:** Clutch and electronic overload protection
**Pros:**

- 300° travel for wider sweeps
- Listed 2 kg·cm torque
- Clutch helps prevent gear damage
- Electronic overload protection
**Cons:**

- Operating voltage not specified in the input
- Not a continuous rotation drive servo
---
## 2Kg 180° Clutch Servo

**Price:** $10.49 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/2kg-180-clutch-servo

The DFRobot 2Kg 180° Clutch Servo is a practical middle ground between a basic 9 g servo and a heavier high-torque unit. It gives standard 180° positional control with clutch protection for mechanisms that may be blocked or handled roughly.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 180°
- **Torque:** 2 kg·cm
- **Operating voltage:** Not specified
- **Protection:** Clutch and electronic overload protection
**Pros:**

- Listed 2 kg·cm torque
- Standard 180° positional range
- Clutch protection against external force
- Good fit for robust model mechanisms
**Cons:**

- Operating voltage not specified in the input
- More specialised than a basic budget micro servo
---
## 9g micro servo (1.6kg)

**Price:** $7.07 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/9g-micro-servo-1-6kg

The DFRobot 9g micro servo is a straightforward compact positional servo with clearly listed beginner-friendly specs. With 1.6 kgf·cm torque at 4.8 V, 180° movement and 0.12 sec/60° no-load speed, it is a tidy choice for small robots and automation tasks.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 180°
- **Torque:** 1.6 kgf·cm at 4.8 V
- **Operating voltage:** 4.8–6 V
- **Speed:** 0.12 sec/60° at 4.8 V
**Pros:**

- Listed 1.6 kgf·cm torque at 4.8 V
- 180° operating angle
- Lightweight 9 g format
- 0.12 sec/60° no-load speed listed
**Cons:**

- Not suitable for heavy joints
- No clutch or metal gear protection mentioned
---
## Sub-micro Servo - SG51R

_Best for ultra-compact builds_

**Price:** $12.46 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/sub-micro-servo-sg51r

The Adafruit SG51R is for the jobs where even a 9 g servo feels too large. It rotates approximately 180° and works with normal servo code, making it useful for very small props, linkages and lightweight mechanisms.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** Approx. 180°
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Best use:** Ultra-compact positional motion
**Pros:**

- Smaller than typical 9 g micro servos
- Approximate 180° positional movement
- Works with common servo libraries
- Good for tight spaces
**Cons:**

- Torque not specified in the input
- Very small size limits mechanical strength
---
## Micro Servo 9g - Continuous

_Best for small wheeled robots_

**Price:** $7.95 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/micro-servo-9g-continuous

The Little Bird Micro Servo 9g - Continuous is the right choice when you want a tiny servo-shaped drive motor rather than an angle-positioning actuator. The signal controls speed and direction, so it suits light wheels, rollers and simple mobile robots.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 360° / continuous
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Best use:** Small wheeled robots
**Pros:**

- Continuous 360° rotation
- Controlled with standard servo libraries
- Compact 9 g format
- Good for beginner robot drive projects
**Cons:**

- Does not move to a commanded angle
- Not a precision position actuator
---
## 2.3KG Serial Bus Servo (6V)

_Best smart servo alternative_

**Price:** $29.02 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/2-3kg-serial-bus-servo-6v

The DFRobot 2.3KG Serial Bus Servo is different from the simple PWM servos in this guide. It uses TTL serial communication, supports daisy-chaining up to 253 servos with IDs, and can operate in 180° or continuous modes, making it useful for more advanced robot builds.

**Key specs:**

- **Control type:** TTL serial bus
- **Rotation range:** 180° and 360° / continuous
- **Torque:** 2.3 kg·cm at 6 V
- **Operating voltage:** 6 V
- **Bus features:** Up to 253 daisy-chained servos, up to 1 Mbps
**Pros:**

- TTL serial control with unique IDs
- Daisy-chain support for up to 253 servos
- Listed 2.3 kg·cm stall torque at 6 V
- Supports 180° and continuous modes
**Cons:**

- Requires serial bus control rather than basic servo PWM
- Higher cost than simple micro servos
---
## MG996 Servo 180° Metal Gear

_Best high-torque option_

**Price:** $8.52 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/mg996-servo-180-metal-gear

The MG996 Servo 180° Metal Gear is the heavy lifter in this comparison. With a listed torque up to 15 kg·cm, metal gears and double ball bearings, it is the servo to consider for stronger robot joints and demanding mechanisms.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 180°
- **Torque:** Up to 15 kg·cm
- **Operating voltage:** 6 V
- **Gears:** Metal
**Pros:**

- Listed torque up to 15 kg·cm
- All-metal gear construction
- Double ball bearings
- Better fit for heavier linkages than micro servos
**Cons:**

- Needs a suitable high-current external supply
- Larger and heavier than 9 g micro servos
---
## Bulk 9 Gram Servo - 10 pack

_Best for classrooms and batch builds_

**Price:** $75.91 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/bulk-9-gram-servo-10-pack

The Bulk 9 Gram Servo - 10 pack is the practical buy for classrooms, clubs and repeat prototypes. Each servo includes horns and screws, with listed 1.6 kg/cm torque at 6.0 V and around 160° rotation range.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** Approx. 160°
- **Torque:** 1.6 kg/cm at 6.0 V
- **Operating voltage:** Not specified
- **Pack size:** 10 servos
**Pros:**

- Ten servos for batch projects
- Includes horns and screw accessories
- Listed 1.6 kg/cm torque at 6.0 V
- Good value for education and spares
**Cons:**

- Not as durable as clutch or metal-gear upgrades
- Around 160° rotation rather than wide travel
---
## TowerPro SG90C 360 Degree Micro Servo (1.6Kg)

**Price:** $7.80 · **Stock:** In stock

**Product page:** https://littlebirdelectronics.com.au/products/towerpro-sg90c-360-degree-micro-servo-1-6kg

The TowerPro SG90C 360 Degree Micro Servo is a compact continuous rotation servo for toy cars, boats, windmill props and DIY drive mechanisms. It behaves more like a DC motor than a positional servo, with direction and speed control but no hardware stop.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** 360° / continuous
- **Torque:** 1.6 kg stated in title
- **Operating voltage:** Not specified
- **Gears:** Plastic
**Pros:**

- 360° continuous rotation
- Light and compact micro format
- Useful for simple drive applications
- Standard servo-style control behaviour
**Cons:**

- Cannot command an exact shaft angle
- Plastic gear drive is not ideal for shock loads
---
## Micro Servo - MG90S High Torque Metal Gear

_Best metal-gear micro upgrade_

**Price:** $20.98 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/micro-servo-mg90s-high-torque-metal-gear

The Adafruit MG90S is the micro-servo upgrade to consider when a basic plastic-gear servo is too fragile. It uses metal gearing and rotates approximately 90°, making it suitable for compact mechanisms that need more resilience over a smaller angular range.

**Key specs:**

- **Control type:** Standard hobby servo PWM
- **Rotation range:** Approx. 90°
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Gears:** Metal
**Pros:**

- Metal gears in a micro-size servo
- Works with standard servo code and libraries
- Good upgrade for small robots
- Compact format
**Cons:**

- Approximate 90° travel is narrower than many 180° micro servos
- Torque not specified in the input
---
## Continuous Rotation Servo [FeeTech FS5103R]

_Best for simple continuous-drive mechanisms_

**Price:** $26.24 · **Stock:** Available (supplier stock)

**Product page:** https://littlebirdelectronics.com.au/products/continuous-rotation-servo-feetech-fs5103r

The FeeTech FS5103R continuous rotation servo is for forward/backward spinning rather than position control. It is easy to use with Arduino Servo library examples and comes with multiple horns, making it useful for simple mobile robots and rotating mechanisms.

**Key specs:**

- **Control type:** Standard hobby servo PWM via digital GPIO
- **Rotation range:** Continuous
- **Torque:** Not specified
- **Operating voltage:** Not specified
- **Best use:** Simple moving robots
**Pros:**

- Continuous forward and backward rotation
- Works with ordinary servo code
- Good for simple moving robots
- Includes multiple horns
**Cons:**

- Does not provide positional angle control
- Torque and voltage are not specified in the input
---

## How we chose

We selected and compared these servos around real maker use rather than only headline torque. A good servo for a classroom is not always the same as a good servo for a robot arm, so we weighted reliability, ease of control, damage tolerance, range of motion and local availability in Australia.

- **Beginner usability** — works with common Arduino, CircuitPython, Raspberry Pi Pico, ESP32 or micro:bit servo examples.
- **Mechanical fit** — useful mix of sub-micro, 9 g micro, standard-size and continuous rotation formats.
- **Protection and durability** — metal gears, clutch mechanisms or electronic overload protection where relevant.
- **Project coverage** — options for pan/tilt mounts, wheels, robot arms, classroom packs, animatronics and serial bus robots.
- **Value and support** — pricing, stock availability, included accessories and suitability for repeat builds in AU classrooms and workshops.

## What is it & how does it work?

A servo is a geared motor with built-in control electronics. A standard positional hobby servo receives a control signal, compares the requested position with its internal feedback, then drives the motor until the output shaft reaches that angle. Most beginner servos use a 3-wire connection: ground, positive supply and signal.

The main types makers will encounter are: **standard positional servos**, which move to an angle such as 0–180°; **micro servos**, which are small 9 g or sub-micro versions for light mechanisms; **continuous rotation servos**, which spin like geared DC motors where the signal controls direction and speed rather than angle; and **smart or serial bus servos**, which use digital communication, IDs and daisy-chaining for robot joints.

Useful vocabulary: **kg·cm** is torque, meaning how much twisting force the servo can produce at a certain distance from the shaft; **stall torque** is the maximum torque at zero movement and should not be treated as a safe continuous rating; **sec/60°** is speed, showing how long the servo takes to move 60 degrees; **PWM** is the usual hobby servo signal; **dead band** is the small signal change a servo ignores; and **metal gears** usually survive shock loads better than plastic gears but can be noisier and heavier.

## What to look at when comparing

Use this checklist before choosing a servo:

- **Torque** — compare kg·cm against the lever length and load. A 1.6 kg·cm micro servo is fine for cardboard mechanisms and tiny pan/tilt mounts; arms, grippers and walking robots need much more margin.
- **Rotation range** — 180° is the normal positional choice, 270° or 300° gives wider motion, 360° usually means continuous rotation rather than precise position, and serial bus servos may support both position and wheel modes.
- **Control type** — most servos here use standard hobby PWM from Arduino-style servo libraries. The DFRobot 2.3KG Serial Bus Servo uses TTL serial and is better when you want many addressable joints on a robot.
- **Operating voltage** — many hobby servos are designed around 4.8–6 V, with some tolerating a wider range. Match the servo supply to the product rating, not just whatever rail is convenient on your microcontroller.
- **Current draw** — stall current is often much higher than beginners expect. Size your power supply for the number of servos moving at once, and add headroom for startup and stalls.
- **Gear material and protection** — metal gears and clutch protection help in mechanisms that may be bumped, blocked or back-driven. Plastic gears are fine for light loads and classroom prototypes.
- **Size and mounting** — 9 g micro servos fit small robots and teaching projects; standard-size high-torque servos suit heavier linkages but need stronger brackets, screws and structure.
- **Number of channels** — one or two servos can be driven directly from many microcontrollers, but larger builds are easier with a driver such as a PCA9685 16-channel board.

**Watch out**Do not power multiple servos from an Arduino 5 V pin or a Raspberry Pi 5 V header and expect reliable results. Share ground with the controller, but feed the servo positive wire from a suitable external 5–6 V supply or battery pack.

## Which one for which project?

Which servo should you buy?

- **Beginner pan/tilt camera or ultrasonic sensor** — choose the Adafruit Micro servo or Little Bird Micro Servo 9g. They are standard positional micro servos that work with ordinary servo libraries and are light enough for small brackets.
- **Classroom STEM kits or batch builds** — choose the Bulk 9 Gram Servo - 10 pack. You get the same style of compact 9 g servo in a cost-effective pack with horns and screws, which matters when students lose parts.
- **Student mechanisms that will be pushed by hand** — choose the DFRobot 9g 180° Clutch Servo or 2Kg 180° Clutch Servo. The clutch and electronic protection make them more forgiving when a linkage jams or a student forces the output arm.
- **Long-travel dial, gauge, eye mechanism or animatronic sweep** — choose the DFRobot 9g 300° Clutch Servo or 2Kg 300° Clutch Servo. The 300° travel gives more motion than standard 180° servos without moving to a continuous rotation design.
- **Small wheeled robot** — choose the Micro Servo 9g - Continuous or TowerPro SG90C 360 Degree Micro Servo. These spin continuously, so they suit light drive wheels where speed and direction matter more than exact angle.
- **Simple continuous-drive mechanism with a larger servo body** — choose the Continuous Rotation Servo FeeTech FS5103R. It is intended for forward/backward rotation and is easy to drive from normal servo code.
- **Robot arm shoulder, heavier gripper or load-bearing linkage** — choose the MG996 Servo 180° Metal Gear if your structure can handle the size and current. Its listed 15 kg·cm torque and metal gears suit tougher joints better than 9 g micro servos.
- **Multi-joint robot with neat wiring and software IDs** — choose the DFRobot 2.3KG Serial Bus Servo. TTL serial daisy-chaining and addressable control are much tidier than running separate PWM signal wires to every joint.

## Buying tips

Cheap servos are often completely fine for first prototypes, light cardboard mechanisms, teaching labs and pan/tilt mounts. Step up when the servo is load-bearing, hidden inside an enclosure, hard to replace, or likely to be stalled by users. In this list, the Little Bird Micro Servo 9g and Bulk 9 Gram Servo pack cover low-cost builds, the DFRobot clutch servos add protection, the MG90S and MG996 add metal gearing, and the serial bus servo adds smarter control.

- **Brands** — Adafruit, DFRobot, FeeTech, TowerPro and Little Bird stocked parts are sensible choices for maker projects because documentation and replacement stock are easier to manage than random unlabelled servos.
- **Buy extras** — add servo extension leads, spare horns, M2/M3 hardware, brackets, a breadboard-friendly power module or 5–6 V supply, and a PCA9685 board if you are controlling many servos.
- **Avoid mystery ratings** — very cheap marketplace servos may quote optimistic torque, have inconsistent centring or use weaker gears than expected. For education, repeatability is usually worth more than saving a few cents.
- **Local AU support** — buying from an Australian supplier helps when you need matching replacements mid-term, fast shipping for a workshop, or advice on a power supply that suits Australian mains power.
- **Plan the mechanics** — a stronger servo will still fail if the horn, bracket, linkage or 3D print flexes. Keep loads close to the shaft and avoid using stall torque as your normal operating point.

**Hot tip**If your project uses three or more servos, design the power and wiring first. Most servo problems that look like bad code are actually voltage dips, missing common ground or a supply that cannot handle startup current.

## Alternatives to consider

Servos are convenient, but they are not always the right actuator. Consider these adjacent categories:

- **Stepper motors** — use when you need precise incremental rotation over many turns, such as camera sliders, plotters and turntables.
- **DC gear motors with motor drivers** — use for drive wheels where continuous rotation, efficiency and speed matter more than position.
- **Linear actuators** — use when you need push-pull motion over a straight stroke rather than rotary movement.
- **Solenoids** — use for fast on/off pushing, locking or striking actions where proportional position is not needed.
- **Smart servos such as Dynamixel-class systems** — use for advanced robots that need feedback, torque limits, daisy-chaining and higher software-level control.

## Bottom line

For most first servo projects, start with the Adafruit Micro servo or Little Bird Micro Servo 9g because they are easy to wire, easy to code and small enough for common maker mechanisms. If you need more durability, the DFRobot clutch servo range is a practical upgrade for student-proof builds, while the MG996 Servo 180° Metal Gear is the better choice for heavier joints. For wheeled robots choose a continuous rotation model, and for multi-servo robotics consider the DFRobot 2.3KG Serial Bus Servo or a dedicated multi-channel servo driver.

## Frequently asked questions

### What is a servo motor used for?

A servo is used when you want a mechanism to move to a controlled position, such as a robot arm joint, pan/tilt camera, latch, gauge needle or animatronic feature. Continuous rotation servos are the exception: they spin like small geared motors and suit wheels or rollers.

### What does kg cm mean on a servo?

kg·cm is a torque rating: roughly how much twisting force the servo can produce at a certain distance from the shaft. For example, 1.6 kg·cm is fine for light micro mechanisms, while a listed 15 kg·cm servo such as the MG996 is a much better starting point for heavier joints.

### Can I power a servo from my Arduino 5V pin?

For a single tiny servo with no load it may appear to work, but it is not good practice. Servos draw high current when starting, moving or stalled, which can reset the Arduino or damage the regulator. Use a separate 5–6 V servo supply and connect the grounds together.

### Why does my Arduino reset when the servo moves?

The usual cause is voltage sag from the servo pulling more current than the board or USB port can supply. Move the servo power wire to a separate supply, keep a common ground with the Arduino, and use thicker or shorter power wiring for multiple servos.

### What is the difference between a 180 degree servo and a 360 degree servo?

A 180° servo moves to a commanded position within its travel range. A 360° servo is usually continuous rotation, meaning the signal controls direction and speed but not exact angle. If you need a wheel, choose continuous; if you need a pointer or arm, choose positional.

### Which servo should I use for a small robot car?

Use a continuous rotation servo such as the Micro Servo 9g - Continuous, TowerPro SG90C 360 Degree Micro Servo or FeeTech FS5103R. These are controlled with normal servo-style signals but behave more like geared motors for forward, reverse and stop.

### Which servo should I use for a robot arm?

For a very small desktop arm, micro servos can work on the gripper or wrist, but they struggle at the shoulder and elbow. Use a higher-torque option such as the MG996 Servo 180° Metal Gear for heavier joints, and design the arm so loads stay close to the pivot.

### Are metal gear servos better than plastic gear servos?

Metal gears are usually better for shock loads, grippers, walking robots and mechanisms that may be bumped or stalled. Plastic gears are lighter, quieter and fine for low-load classroom builds. For a micro upgrade, the MG90S metal-gear servo is a sensible step up from a basic 9 g plastic-gear servo.

### What is a clutch servo?

A clutch servo includes a mechanism that helps protect the gears if the output is forced or blocked. The DFRobot 9g, 2Kg and 6Kg clutch servos in this guide are good choices for student projects, interactive exhibits and mechanisms that may be pushed by hand.

### How many servos can an Arduino control?

An Arduino can generate signals for several servos using the Servo library, but power becomes the real limit before code does. For many servos, use an external servo supply and consider a PCA9685 16-channel driver board so the wiring and timing are cleaner.

### Can I control servos from a Raspberry Pi?

Yes, but the Raspberry Pi should not power servos directly from its header for anything beyond tiny experiments. Use an external servo supply, common ground, and preferably a PCA9685 servo driver to provide stable PWM signals without Linux timing jitter.

### Why is my servo jittering?

Servo jitter is commonly caused by noisy or weak power, a missing common ground, loose signal wiring or mechanical load fighting the servo. Try a separate supply, shorter wires, secure connections and make sure the linkage is not binding.

### Why is my servo getting hot?

A servo gets hot when it is stalled, overloaded, forced against a mechanical stop or constantly correcting against a load. Reduce the load, change the linkage geometry, use a higher-torque servo such as the MG996 for heavy joints, or add clutch protection if users may push the mechanism.

### Do I need a digital servo or a smart servo?

For most beginner Arduino and classroom projects, a normal PWM servo is simpler and cheaper. Step up to a serial bus or smart servo when you need daisy-chained wiring, unique IDs, many joints or more advanced control; the DFRobot 2.3KG Serial Bus Servo is the smart-style option in this comparison.

### Are cheap 9g servos good enough?

Yes, for light mechanisms, prototypes, pan/tilt mounts and education they are often the right choice. The Little Bird Micro Servo 9g is the value pick, while the Bulk 9 Gram Servo - 10 pack makes sense when you need matching spares for a class or club.

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Reviewed by **Marcus Schappi** — Co-founder, Little Bird Electronics. Working with Australian makers, educators and engineers since 2011.