The Nema 17 stepper motor is a 2-phase motor with a 1.8-degree step, meaning 200 steps per full revolution. It is used for axis movement in 3D printers, CNC routers, laser engravers, and other positioning systems. It operates at 1.5A per phase, with a voltage of 4.8V per phase. The holding torque of 32N.cm makes it suitable for the X, Y, Z axes and for the extruder of hobby and DIY 3D printers. The 42 x 42 x 34mm housing follows the Nema 17 format, so it mounts directly into standard brackets.

Among its main features are precise positioning without feedback sensors, the detent torque of 1.2N.cm that holds the shaft in position even with power off, and operation with microstepping for smoother and quieter movement. Its compact dimensions make it easy to integrate into projects with limited space.

The motor is controlled through a dedicated driver, such as the A4988 or DRV8825. It is compatible with Arduino boards (Uno, Nano, Mega 2560), including with CNC Shield V3 or RAMPS 1.4. It also works with ESP32, STM32, and 3D printer control boards, with firmware such as Marlin, Klipper, or GRBL. Through microstepping, the A4988 driver allows up to 1/16 step (3200 steps per revolution), and the DRV8825 up to 1/32 step (6400 steps per revolution).

The 4.8V per phase value is the voltage drop across the coil at nominal current. In practice, the driver is powered at 12VDC and limits the current through the coils itself, so the driver current limit must be set correctly. The motor should never be connected directly to the power supply.

Specifications:

Step: 1.8 degrees

Steps per revolution: 200 (full step)

Current per phase: 1.5A

Voltage per phase: 4.8V

Number of phases: 2

Holding torque: 32N.cm

Detent torque: 1.2N.cm

Recommended voltage (driver supply): 12VDC

Compatible drivers: A4988, DRV8825

Dimensions: 42 x 42 x 34mm

Pinout:

Wire colors vary from one manufacturer to another. The wires of the same coil can be easily identified with a multimeter on the resistance range. Between wires of the same phase, a few ohms are measured, while there is no continuity between wires from different phases. If the motor vibrates without rotating, the wire pairs are connected incorrectly. If it rotates in the opposite direction, swap the wires of one phase only (for example A+ with A-) or reverse the direction in firmware.

Signal	Coil	A4988 Driver	DRV8825 Driver
A+	Phase A	1A	A1
A−	Phase A	1B	A2
B+	Phase B	2A	B1
B−	Phase B	2B	B2

Usage:

Use a multimeter to identify the wire pairs of the two coils.

Mount the A4988 or DRV8825 driver on the control board (CNC Shield, RAMPS, or printer board), respecting the orientation indicated on the board.

If you use the driver without a shield, connect the RESET and SLEEP pins together.

Set the current limit using the driver potentiometer by measuring the VREF voltage.

For the DRV8825 with 0.1 ohm sense resistors (marked R100), the formula is VREF = I / 2, so 0.75V for 1.5A.

For the A4988, the formula is VREF = I x 8 x Rs. With R100 resistors, this gives 1.2V for 1.5A. Check the resistor marking next to the chip, because the value differs between modules.

Start at 70-80% of the nominal current and increase only if the motor loses steps.

At 1.5A, the A4988 driver needs a heatsink and active cooling with a fan.

With power off, connect the motor to the driver outputs according to the pinout table.

Connect the 12VDC supply to the driver power input (VMOT and GND), with an electrolytic capacitor of at least 100uF close to the driver if the board does not already have one.

Set microstepping using the MS1, MS2, MS3 jumpers (A4988) or M0, M1, M2 (DRV8825).

In firmware (Marlin, Klipper, GRBL), configure the number of steps per mm according to the microstepping and the transmission (belt or lead screw).

Turn on the power and test movement at low speed, then gradually increase speed and acceleration.

After a few minutes of operation, check the temperature of the motor and the driver. It is normal for the motor to warm up, but if it becomes too hot to touch, reduce the current limit.