Stepper Motor: Unipolar/Bipolar, 200 Steps/Rev, 57×56mm, 7.4V, 1 A/Phase

This NEMA 23-size hybrid stepping motor can be used as a unipolar or bipolar stepper motor and has a 1.8° step angle (200 steps/revolution). Each phase draws 1 A at 7.4 V, allowing for a holding torque of 9 kg-cm (125 oz-in).

6-lead, unipolar/bipolar stepper motor wires are terminated with bare leads.

6-lead, unipolar/bipolar stepper motor wiring diagram.

Overview

This high-torque hybrid stepping motor has a 1.8° step angle (200 steps/revolution). Each phase draws 1 A at 7.4 V, allowing for a holding torque of 9 kg-cm (125 oz-in). The motor has six color-coded wires terminated with bare leads that allow it to be controlled by both unipolar and bipolar stepper motor drivers. When used with a unipolar stepper motor driver, all six leads are used. When used with a bipolar stepper motor driver, the center-tap yellow and white wires can be left disconnected (the red-blue pair gives access to one coil and the black-green pair gives access to the other coil). We recommend using it as a bipolar stepper motor and controlling it with one of our bipolar stepper motor drivers or one of our Tic Stepper Motor Controllers. In particular, the Tics make control easy because they support six different interfaces (USB, TTL serial, I²C, RC, analog voltages, and quadrature encoder) and are configurable over USB with our free configuration utility.

NEMA 23 stepper motor (item #1475) mounted with a steel L-bracket for NEMA 23 stepper motors.

Our 1/4″ universal mounting hub and 1/4″ scooter wheel adapter can be used to mount objects on the stepper motor’s 1/4″-diameter output shaft, and we carry a NEMA 23 steel bracket for securely mounting this stepper motor to a flat surface (the picture above shows this bracket being used with a taller NEMA 23 stepper motor).

Specifications

• Size: 56.4 mm square × 56 mm, not including the shaft (NEMA 23)
• Weight: 0.7 kg (25 oz)
• Shaft diameter: 6.35 mm (0.25″) “D”
• Steps per revolution: 200
• Current rating: 1 A per coil
• Voltage rating: 7.4 V
• Resistance: 7.4 Ω per coil
• Holding torque: 9 kg-cm (125 oz-in)
• Inductance: 10 mH per coil
• Lead length: 30 cm (12″)
• Output shaft supported by two ball bearings

More specifications are available in the datasheet (46k pdf).

Dimensions

The following diagram shows the stepper motor dimensions in mm. The output D-shaft has a 0.25″ (6.35 mm) diameter with a section that is flattened by 0.5 mm (note: the diagram below incorrectly lists this flattened width as 6 mm when it is really 5.85 mm). This shaft works with our 1/4″ universal mounting hub and 1/4″ scooter wheel adapter.

The inside of a bipolar stepper motor (SOYO NEMA 14-size).

Stepper Motor Applications

Stepper motors are generally used in a variety of applications where precise position control is desirable and the cost or complexity of a feedback control system is unwarranted. Here are a few applications where stepper motors are often found:

• Printers
• CNC machines
• 3D printer/prototyping machines (e.g. RepRap)
• Laser cutters
• Pick and place machines
• Linear actuators
• Hard drives

Pololu’s assortment of stepper motors.

Note: This stepper motor is SOYO part number SY57STH56-1006A.