Stepper Motor: Bipolar, 200 Steps/Rev, 20×42mm, 4.3V, 0.8 A/Phase

This small NEMA 8-size hybrid bipolar stepping motor has a 1.8° step angle (200 steps/revolution). Each phase draws 800 mA at 4.3 V, allowing for a holding torque of 300 g-cm (4.2 oz-in). With a weight of 80 g, this is one of the smaller stepper motors we carry.

This small hybrid bipolar stepping motor has a 1.8° step angle (200 steps/revolution). Each phase draws 800 mA at 4.3 V, allowing for a holding torque of 300 g-cm (4.2 oz-in). The motor has four color-coded wires terminated with bare leads: black and green connect to one coil; red and blue connect to the other. These leads connect to the stepper motor through a removable JST-ZHR-5 connector. The motor can be controlled by a pair of suitable H-bridges (one for each coil), but we recommend using a bipolar stepper motor driver 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.

Our 4 mm universal mounting hub can be used to mount objects on the stepper motor’s 4 mm-diameter output shaft. For a slightly less powerful motor in the same NEMA size but a shorter length, consider Stepper Motor: Bipolar, 200 Steps/Rev, 20×30mm, 3.9V, 0.6 A/Phase. A comparison between these two motors can be seen in the image below.

Specifications

• Size: 20 mm square × 42 mm, not including the shaft (NEMA 8)
• Weight: 80 g (2.8 oz)
• Shaft diameter: 4 mm “D”
• Steps per revolution: 200
• Current rating: 800 mA per coil
• Voltage rating: 4.3 V
• Resistance: 5.4 Ω per coil
• Holding torque: 300 g-cm (4.2 oz-in)
• Inductance: 1.5 mH per coil
• Lead length: 30 cm (12″)
• Output shaft supported by two ball bearings

More specifications are available in the datasheet (28k pdf).

Dimensions

The “Length” is 30 mm. The output D-shaft has a length of 15 mm and a 4 mm diameter with a section that is flattened by 0.5 mm. This shaft works with our 4 mm universal mounting hub.

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
• Laser cutters
• Pick and place machines
• Linear actuators
• Hard drives

Note: This stepper motor is SOYO part number SY20STH42-0804A.