Servo vs Stepper vs DC Motor: Which Motor for Which Project?

Written and fact-checked by Compoden's engineering team, India. Every spec and price below is read from our live catalogue record for the exact part named. Published 19 August 2026 · Last updated 19 August 2026.

These three get grouped as "motors" and picked by whichever one a tutorial happened to use, but they solve three different control problems. A servo answers "hold this exact angle." A stepper answers "turn exactly this many degrees, precisely, every time." A DC motor answers "just spin, as fast as I tell you." Picking the wrong one doesn't just cost you money — it usually means fighting the part to do a job it was never built for.

SG90 Servo, TT Gear DC Motor and NEMA 17 Stepper — catalogue records checked August 2026

Spec	SG90 Servo	TT Gear DC Motor	NEMA 17 Stepper
Price (India, COD)	Rs.120	Rs.180	Rs.830
Motion type	0-180° positional	Continuous rotation only	Discrete 1.8° steps (200/rev)
Control signal	PWM angle pulse	Voltage / PWM duty cycle	Step + direction pulses
External driver needed	No — signal wire only	Yes (L298N, L293D)	Yes (A4988, DRV8825, TMC2209)
Voltage	4.8–6V	3–6V	12–24V (via driver)
Position feedback	Internal, built-in	None	None (open-loop)

Verdict in one line: if the job needs an exact angle held, buy the servo; if it needs exact repeatable turns, buy the stepper and its driver; if it just needs to spin, buy the DC motor and its driver.

Comparing motor price alone is misleading, because two of these three arrive as half a system. The SG90 needs nothing else — Rs.120 buys a complete, working part. The TT Gear Motor needs an L298N or similar driver to be usable at all; add our L298N at Rs.180 and the real cost of a working DC motor system is Rs.360. The NEMA 17 needs a stepper driver like the A4988; add that at Rs.180 and a working stepper system is Rs.1,010 — over eight times the servo's all-in price. None of these numbers are wrong on their own, but only the servo's sticker price is also its system price.

How does each motor actually move?

Three different mechanisms entirely. A servo has a small DC motor, a gearbox, and — critically — its own potentiometer and control board built in; it reads the PWM pulse width you send and drives itself to match that angle, correcting continuously, which is why our record marks it "self_driven" and needing nothing external but a signal wire. A stepper has no feedback at all: its driver energises coils in a fixed sequence, and each pulse advances the shaft by exactly one step (1.8° on this NEMA 17, 200 steps per full turn) — it doesn't know its angle, it just counts pulses and trusts the count. A DC motor has neither positioning nor stepping; feed it voltage and it spins, feed it more and it spins faster, and that's the entire interface.

Which one needs an external driver board, and which doesn't?

Only the servo skips this entirely. Our SG90 record lists no driver requirement — it takes a single PWM signal pin (plus power and ground) straight from an Arduino or ESP32 GPIO. The TT Gear Motor's own record states plainly: "requires a motor driver like L298N or L293D; do not connect directly to GPIO" — a GPIO pin cannot supply the current a DC motor draws under load, and driving it directly risks the pin. The NEMA 17's record is equally direct: "requires a stepper driver (e.g., A4988, DRV8825, TMC2209)," because a stepper's coils need sequenced, higher-current pulses no microcontroller pin can generate on its own. These two driver types are not interchangeable — an L298N cannot drive a stepper's step/direction protocol, and an A4988 has no mode for a plain DC motor.

Which one can spin continuously, and which can't?

Only the DC motor is built for it. The SG90 is a positional servo, 0-180° only — our record states this range directly, and pushing it past that mechanical limit strips the plastic gears rather than continuing to rotate. If you specifically need continuous rotation in a servo form factor, that's a genuinely different part (a continuous-rotation servo, which trades position-holding for the ability to spin like a geared DC motor under PWM control) — not this one modified in software. The NEMA 17 technically can turn indefinitely, but doing so fast defeats its purpose: steppers are chosen for precise, often start-stop motion, not sustained high-speed spinning, which is what a DC motor is for and does more efficiently.

What's the one ESP32 trap with servo code?

The library name changes, and using the wrong one won't even compile. Our record states it explicitly: "on ESP32/C3/S3/C6 you MUST include ESP32Servo.h, NOT Servo.h — the AVR Servo lib will not compile on ESP32." The API is otherwise identical — attach(pin), then write(0-180) for degrees or writeMicroseconds(500-2500) for finer control — so a sketch written for an Uno needs exactly one line changed to run on an ESP32, but that line matters.

What actually breaks on each of these motors?

Three different failure patterns, each recorded on its own part. The SG90's known issues are mechanical and electrical: "plastic gears can strip under high load or shock," and separately, "jittery movement if power supply is noisy or insufficient" — a servo drawing its listed 700mA peak current from a shared, underpowered 5V rail will visibly twitch before it ever strips a gear. The NEMA 17's own record lists "overheating if current exceeds 1.5A without cooling" and "resonance at low speeds without microstepping" — a stepper's failure is usually thermal or a subtle loss of steps, not a dramatic stop. The TT Gear Motor's record names "brush wear over time" and "gearbox may strip under sustained high load," plus a detail worth planning around: "no built-in encoder (unless added separately)" — meaning a stalled or slipping TT motor gives your code no way to know it isn't turning, unlike a stepper's driver, which at least reports a stall condition on some models.

Which one holds the most torque?

Not a fair fight by the numbers alone, because the units and price tiers differ so much: the SG90 delivers 1.2 kg·cm stall torque at 4.8V, the TT Gear Motor 0.8 kg·cm at 6V, and the NEMA 17 a stall torque of 4.59 kg·cm (0.45 Nm holding torque) — roughly 4-6x either of the smaller two. That comparison alone would suggest always buying the stepper, but torque isn't the job these parts are chosen for individually: the servo's torque only matters at a fixed angle, the DC motor's only matters while spinning, and the stepper's only matters holding a position between steps. A NEMA 17 is not "a stronger servo" — it is a completely different control model that happens to also produce more torque.

Which motor should you actually buy?

For a pan-tilt mount, a robotic arm joint, or anything holding a set angle, the SG90 Servo Motor (Rs.120) — nothing else to buy. For a robot's drive wheels or a conveyor, the TT Gear Motor (Rs.180) plus an L298N driver (Rs.180). For a 3D printer axis, a CNC, or a camera slider that needs exact repeatable positioning, the NEMA 17 Stepper (Rs.830) plus an A4988 driver (Rs.180). All available cash on delivery across India.

What should you read next?

Wiring up the DC motor option? Our L298N wiring and heat guide covers that driver in depth, and the Arduino Uno pinout reference is worth checking before you claim pins for any of these three.

Not sure which motor your build needs? Open Soldr, describe what the motor has to do, and it will pick the right one and its driver.

Frequently asked questions

Servo, stepper ya DC motor - kaunsa motor lein?

Agar ek exact angle par rukna hai (jaise camera mount ya robot arm joint), servo lein (Rs.120) - isko koi alag driver nahi chahiye. Agar bar-bar exact precision se ghumna hai (3D printer, CNC), NEMA 17 stepper lein (Rs.830) lekin A4988 driver (Rs.180) bhi chahiye hoga. Agar bas continuously ghoomna hai (robot ke pahiye), TT gear motor lein (Rs.180) L298N driver (Rs.180) ke saath.

Does a servo motor need a separate driver board?

No. Our SG90 record lists no external driver requirement — it takes a single PWM signal wire directly from an Arduino or ESP32 GPIO pin, plus power and ground. This is different from both the DC motor and the stepper, which our records state explicitly need an external driver (L298N/L293D for the DC motor, A4988/DRV8825/TMC2209 for the stepper) because a GPIO pin cannot supply the current or the sequenced pulses either one needs.

Can a servo motor spin continuously like a DC motor?

Not this one. Our SG90 record states a 0-180 degree range; pushing past that mechanical limit strips its plastic gears rather than letting it keep rotating. A separate part, a continuous-rotation servo, exists specifically for that use case and trades away position-holding to get it — it isn't the same servo used differently.

Why does my stepper motor code work on Arduino but not compile on ESP32?

You're likely including the wrong servo library, not a stepper library issue specifically — but the same trap applies broadly. Our own SG90 record states directly that ESP32, C3, S3 and C6 boards require ESP32Servo.h, not the standard Servo.h, because the AVR Servo library will not compile on ESP32. The rest of the API (attach, write, writeMicroseconds) stays identical.

What is the price of a servo, DC motor and stepper motor in India?

At Compoden, the SG90 Servo Motor is Rs.120, the TT Gear DC Motor is Rs.180, and the NEMA 17 Stepper Motor is Rs.830. Counting their required drivers, a working DC motor system (with an L298N) is Rs.360, and a working stepper system (with an A4988) is Rs.1,010. All available with cash on delivery across India. Prices checked August 2026.