> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # Stepper Motor with 18cm Lead Screw: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase **Type:** Product page · **SKU:** POLOLU-2689 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia) **Page:** https://core-electronics.com.au/stepper-motor-with-18cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html ([markdown](https://core-electronics.com.au/stepper-motor-with-18cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html.md)) This NEMA 17-size hybrid bipolar stepping motor has an integrated 18 cm (7″) threaded rod as its output shaft, turning it into a linear actuator capable of precision open-loop positioning. The included traveling nut has four mounting holes and moves 40 µm (1.6 mil) per full step; finer resolution can be achieved with microstepping. The stepper motor has a 1.8° step angle (200 steps/revolution) and each phase draws 1.7 A at 2.8 V, allowing for a holding torque of 3.7 kg-cm (51 oz-in). ## Pricing - **Price:** $184.95 (inc GST) — $168.14 AUD, exc GST - **Quantity discounts:** 5+ $163.09 (exc GST) · 10+ $159.73 (exc GST) ## Availability & dispatch - Available with a lead time — expect dispatch between Aug 24 and Aug 25. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=POLOLU-2689:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/POLOLU-2689:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description **Details for item #2689** The lead screw built into this stepper motor extends 18 cm (7") from the face of the stepper motor and weighs 352 g (12.4 oz). Pololu also carry versions of this stepper motor with a [28 cm](https://core-electronics.com.au/stepper-motor-with-28cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html) and [38 cm lead screw](https://core-electronics.com.au/stepper-motor-with-38cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), and Pololu also have the stepper motor available [without a lead screw](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html). | ![](https://core-electronics.com.au/attachments/localcontent/0J5065_3763140a307.jpg) | |---| | Stepper motor with 28cm lead screw: bipolar, 200 steps/rev, 42×38mm, 2.8V, 1.7 A/phase. | | ![](https://core-electronics.com.au/attachments/localcontent/0J5103_327239b9c3e.gif) | |---| | When the nut is prevented from rotating, it travels up or down the rod as the motor rotates. | This linear positioning drive consists of Pololu's [42×38 mm NEMA17 stepper motor](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html) with a built-in lead screw in place of the normal output shaft, which makes it easy to move an object or platform in a linear motion with the precision of a stepper motor. Motors like this are especially popular for use in home-built 3D printers (e.g. RepRap) and CNC machines. The stainless steel threaded rod extends from the face of the stepper motor, and since it is integrated into the motor itself, you do not have to deal with bulky shaft couplers or loose set screws. This stepper motor comes in three versions with different length lead screws built in: [18 cm](https://core-electronics.com.au/stepper-motor-with-18cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), [28 cm](https://core-electronics.com.au/stepper-motor-with-28cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), and [38 cm](https://core-electronics.com.au/stepper-motor-with-38cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html). | [![](https://core-electronics.com.au/attachments/localcontent/0J6208_13456402cd9.jpg)](https://core-electronics.com.au/attachments/localcontent/0J6208_2156848a4de.jpg) | |---| | NEMA 17-size stepper motors with 18, 28, and 38cm lead screws. | The included copper alloy [traveling nut](https://core-electronics.com.au/traveling-nut-for-tr8-8-p2-threaded-rods.html) (also known as a carriage nut) features a mounting flange with four holes threaded for [M3 screws](https://core-electronics.com.au/hardware/screws-nuts.html). The nut moves 8.0 mm per full revolution of the lead screw, which allows for a linear resolution of 0.040 mm per full step of the stepper motor. Even smaller step sizes can be achieved through microstepping, which is a feature of many [bipolar stepper motor drivers](https://core-electronics.com.au/breakout-boards-and-modules/motor-drivers-controllers/stepper-motor-drivers.html). Pololu recommend the [MP6500 stepper motor driver carrier](https://core-electronics.com.au/category/229/mp6500-stepper-motor-driver-carriers) or [AMIS-30543 stepper motor driver carrier](https://core-electronics.com.au/amis-30543-stepper-motor-driver-carrier.html) for use with this stepper motor, the latter of which allows for a linear resolution of 1.25 µm per 1/32 microstep. However, please note that the nut is not spring loaded, so changes in direction will result in loss of positioning precision due to backlash. Extra [traveling nuts](https://core-electronics.com.au/traveling-nut-for-tr8-8-p2-threaded-rods.html) are also available for purchase separately. The maximum achievable linear speed depends a lot on the details of the system, including the load and motor supply voltage. Under ideal conditions (e.g. with gradual ramping up of the step rate, a high supply voltage, and no load), Pololu were able to achieve speeds close to 30 cm/s (12 in/s) with the 28 cm lead screw version. The stepper motor has a 1.8° step angle (200 steps/revolution) and each phase draws 1.7 A at 2.8 V, allowing for a holding torque of 3.7 kg-cm (51 oz-in). The motor has four color-coded wires terminated with a JST XHP-4 connector with 0.1" spacing: black and green connect to one coil; red and blue connect to the other. It 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. | \| [![](https://core-electronics.com.au/attachments/localcontent/0J5066_3831296214.jpg)](https://core-electronics.com.au/attachments/localcontent/0J5066_62466b9e3fb.jpg) \| \|---\| \| The JST XHP-4 connector that terminates the leads of the NEMA 17 stepper motor with 28cm lead screw. \| | \| ![](https://core-electronics.com.au/attachments/localcontent/0J2296_4089d30f05.jpg) \| \|---\|---\| \| Bipolar stepper motor wiring diagram. \| | |---| Pololu's [NEMA 17 aluminum bracket](https://core-electronics.com.au/pololu-stamped-aluminum-l-bracket-for-nema-17-stepper-motors.html) offers a variety of options for mounting this stepper motor in your project: | [![](https://core-electronics.com.au/attachments/localcontent/0J5663_207184dbf8c.jpg)](https://core-electronics.com.au/attachments/localcontent/0J5663_2408058d4ce.jpg) | |---| | NEMA 17 stepper motor with lead screw mounted with a stamped aluminum L-bracket. | **Specifications** - Size: 42.3 mm square × 38 mm, not including the shaft (NEMA 17) - Leadscrew: *Tr 8 × 8(P2)* - Steps per revolution: 200 - Linear step size: 40 µm (1.6 mil) per full step - Current rating: 1.68 A per coil - Voltage rating: 2.8 V - Resistance: 1.65 O per coil - Holding torque: 3.7 kg-cm (51 oz-in) - Inductance: 3.2 mH per coil - Lead length: 16 cm (6.5") - Output shaft supported by two ball bearings More specifications are available in the [datasheet](https://core-electronics.com.au/attachments/localcontent/SY42STH38-1684A_6344301aaf7.pdf) (63k pdf). Note that while the datasheet is for the stepper motor with 28 cm lead screw, the only difference between the three versions is the length of the lead screw. **Dimensions** The following diagram shows the stepper motor, lead screw, and traveling nut dimensions in mm. The value of `L` is 182 mm for the [stepper motor with 18cm lead screw](https://core-electronics.com.au/stepper-motor-with-18cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), 282 mm for the [stepper motor with 28cm lead screw](https://core-electronics.com.au/stepper-motor-with-28cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), and 382 mm for the [stepper motor with 38cm lead screw](https://core-electronics.com.au/stepper-motor-with-38cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html). Note that the datasheet incorrectly labels the threaded rod as “TR8×3”; it is really a ***Tr8×8(P2)*** leadscrew, which is the ISO designation for a trapezoidal metric thread with an 8 mm nominal diameter, 8 mm lead, and 2 mm pitch. (Put more simply, the rod has four independent threads spaced 2 mm apart, so the carriage nut advances 8 mm for each full revolution of the rod.) | ![](https://core-electronics.com.au/attachments/localcontent/0J5075_55177e37403.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 (e.g. RepRap) - Laser cutters - Pick and place machines - Linear actuators - Hard drives | ![](https://core-electronics.com.au/attachments/localcontent/0J4511_6816439839d.jpg) | |---| **Note:** This stepper motor is SOYO part number SY42STH38-1684A. **People often buy this product together with:** | [![Pololu Stamped Aluminum L-Bracket for NEMA 17 Stepper Motors](https://core-electronics.com.au/attachments/localcontent/0J5626_2887ef923a.jpg)](https://core-electronics.com.au/pololu-stamped-aluminum-l-bracket-for-nema-17-stepper-motors.html) | [Pololu Stamped Aluminum L-Bracket for NEMA 17 Stepper Motors](https://core-electronics.com.au/pololu-stamped-aluminum-l-bracket-for-nema-17-stepper-motors.html) | |---|---| | [![Stepper Motor: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase](https://core-electronics.com.au/attachments/localcontent/0J5063_3948a41661.jpg)](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html) | [Stepper Motor: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase](https://core-electronics.com.au/stepper-motor-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html) | |---|---| | [![Traveling Nut for TR8×8(P2) Threaded Rods](https://core-electronics.com.au/attachments/localcontent/0J6212_450589bd97.jpg)](https://core-electronics.com.au/traveling-nut-for-tr8-8-p2-threaded-rods.html) | [Traveling Nut for TR8×8(P2) Threaded Rods](https://core-electronics.com.au/traveling-nut-for-tr8-8-p2-threaded-rods.html) | |---|---| **Dimensions** | Size: | 42.3 mm square × 38 mm (NEMA 17)[1](https://core-electronics.com.au/#note1) | |---|---| | NEMA size: | 17 | | Weight: | 355 g[2](https://core-electronics.com.au/#note2) | | Shaft diameter: | 8 mm | **General specifications** | Shaft type: | 18 cm threaded rod[3](https://core-electronics.com.au/#note3) | |---|---| | Current rating: | 1680 mA[4](https://core-electronics.com.au/#note4) | | Voltage rating: | 2.8 V | | Holding torque: | 51 oz·in | | Steps per revolution: | 200 | | Resistance: | 1.65 Ohm[4](https://core-electronics.com.au/#note4) | | Inductance per phase: | 3.2 mH | | Number of leads: | 4 | | Lead length: | 16 cm[5](https://core-electronics.com.au/#note5) | **Notes:** 1Not including the shaft.2This measurement includes the traveling nut, which adds 11.6 g (0.41 oz).3ISO definition of thread characteristics: Tr 8 × 8(P2) – trapezoidal thread, 8 mm diameter, 8 mm lead, 2 mm pitch.4Per coil.5After twisting. **File downloads** - **[SY42STH38-1684A stepper motor with 28cm lead screw datasheet](https://core-electronics.com.au/attachments/localcontent/SY42STH38-1684A_6344301aaf7.pdf) (63k pdf)** Note that while this datasheet is specifically for the stepper motor with 28 cm lead screw, the only difference between the three versions ([18 cm](https://core-electronics.com.au/stepper-motor-with-18cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), [28 cm](https://core-electronics.com.au/stepper-motor-with-28cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html), and [38 cm](https://core-electronics.com.au/stepper-motor-with-38cm-lead-screw-bipolar-200-steps-rev-42-38mm-2-8v-1-7-a-phase.html)) is the length of the lead screw. ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/p/o/pololu-2689-1.jpg)