# Stepper Motor: Bipolar, 200 Steps/Rev, 20×42mm, 4.3V, 0.8 A/Phase **Type:** Product page · **SKU:** POLOLU-2256 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia) **Page:** https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-42mm-4-3v-0-8-a-phase.html ([markdown](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-42mm-4-3v-0-8-a-phase.html.md)) 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... ## Pricing - **Price:** $124.95 (inc GST) — $113.59 AUD, exc GST - **Quantity discounts:** 5+ $109.05 (exc GST) · 10+ $105.64 (exc GST) ## Availability & dispatch - Available with a lead time — expect dispatch between Aug 31 and Sep 01. ## Description | [![](https://core-electronics.com.au/attachments/localcontent/0J2286_1892927f0cd.jpg)](https://core-electronics.com.au/attachments/localcontent/0J2286_1641576afb9.jpg) | |---| | Bipolar stepper motor wires are terminated with bare leads. | | ![](https://core-electronics.com.au/attachments/localcontent/0J2296_2723a56f97.gif) | |---| | Bipolar stepper motor wiring diagram. | 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 Pololu recommend using a [bipolar stepper motor driver](https://core-electronics.com.au/breakout-boards-and-modules/motor-drivers-controllers/stepper-motor-drivers.html) or one of Pololu's [Tic Stepper Motor Controllers](https://core-electronics.com.au/breakout-boards-and-modules/motor-drivers-controllers/stepper-motor-drivers.html). 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 Pololu's free configuration utility. Pololu's [4 mm universal mounting hub](https://core-electronics.com.au/pololu-universal-aluminum-mounting-hub-for-4mm-shaft-4-40-holes-2-pack.html) 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](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-30mm-3-9v-0-6-a-phase.html). A comparison between these two motors can be seen in the image below. | [![](https://core-electronics.com.au/attachments/localcontent/0J11420_182436abd35.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11420_53692f64bf8.jpg) | |---| | [SY20STH30-0604A](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-30mm-3-9v-0-6-a-phase.html) (top) and [SY20STH42-0804A](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-42mm-4-3v-0-8-a-phase.html) (bottom). | **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 O 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](https://core-electronics.com.au/attachments/localcontent/SY20STH42-0804A_2826660405d.pdf) (28k pdf). **Dimensions** The following diagram shows the stepper motor dimensions in mm. The dimension labeled “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 Pololu's [4 mm universal mounting hub](https://core-electronics.com.au/pololu-universal-aluminum-mounting-hub-for-4mm-shaft-4-40-holes-2-pack.html). | ![](https://core-electronics.com.au/attachments/localcontent/0J11421_282403dc219.jpg) | |---| | [![](https://core-electronics.com.au/attachments/localcontent/0J2297_3186898a777.jpg)](https://core-electronics.com.au/attachments/localcontent/0J2297_246528185f4.jpg) | |---| | 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 - Laser cutters - Pick and place machines - Linear actuators - Hard drives | ![](https://core-electronics.com.au/attachments/localcontent/0J4511_6816439839d.jpg) | |---| | Pololu’s assortment of stepper motors. | **Note:** This stepper motor is SOYO part number SY20STH42-0804A. **People often buy this product together with:** | [![Pololu Universal Aluminum Mounting Hub for 4mm Shaft, #4-40 Holes (2-Pack)](https://core-electronics.com.au/attachments/localcontent/0J1106_30989f4660.jpg)](https://core-electronics.com.au/pololu-universal-aluminum-mounting-hub-for-4mm-shaft-4-40-holes-2-pack.html) | [Pololu Universal Aluminum Mounting Hub for 4mm Shaft, #4-40 Holes (2-Pack)](https://core-electronics.com.au/pololu-universal-aluminum-mounting-hub-for-4mm-shaft-4-40-holes-2-pack.html) | |---|---| | [![Stepper Motor: Bipolar, 200 Steps/Rev, 20×30mm, 3.9V, 0.6 A/Phase](https://core-electronics.com.au/attachments/localcontent/0J2280_32574cb22f.jpg)](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-30mm-3-9v-0-6-a-phase.html) | [Stepper Motor: Bipolar, 200 Steps/Rev, 20×30mm, 3.9V, 0.6 A/Phase](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-20-30mm-3-9v-0-6-a-phase.html) | |---|---| | [![Stepper Motor: Bipolar, 200 Steps/Rev, 28×45mm, 4.5V, 0.67 A/Phase](https://core-electronics.com.au/attachments/localcontent/0J2282_3184112e7b.jpg)](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-28-45mm-4-5v-0-67-a-phase.html) | [Stepper Motor: Bipolar, 200 Steps/Rev, 28×45mm, 4.5V, 0.67 A/Phase](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-28-45mm-4-5v-0-67-a-phase.html) | |---|---| **Dimensions** | Size: | 20 mm square × 42 mm[1](https://core-electronics.com.au/#note1) | |---|---| | NEMA size: | 8 | | Weight: | 80 g | | Shaft diameter: | 4 mm | **General specifications** | Shaft type: | 4 mm "D" | |---|---| | Current rating: | 800 mA[2](https://core-electronics.com.au/#note2) | | Voltage rating: | 4.3 V | | Holding torque: | 4.2 oz·in | | Steps per revolution: | 200 | | Resistance: | 5.4 Ohm[2](https://core-electronics.com.au/#note2) | | Inductance per phase: | 1.5 mH | | Number of leads: | 4 | | Lead length: | 30 cm | **Notes:** 1Not including the shaft.2Per coil. **File downloads** - **[SY20STH42-0804A stepper motor datasheet](https://core-electronics.com.au/attachments/localcontent/SY20STH42-0804A_2826660405d.pdf) (28k pdf)** - **3D model of the SY20STH42-0804A stepper motor (Pololu item #2256) (3MB step)** ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/i/m/image_11987.jpg)