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Stepper Motor with 18cm Lead Screw: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase


$79.95 AUD, inc GST
$72.68 AUD, exc GST
Stepper Motor with 18cm Lead Screw: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase
79.95 AUD


$79.95 AUD, inc GST
$72.68 AUD, exc GST


  • $6.95 Standard (2-4 days, tracked)
  • $9.95 Express (Overnight*, tracked)
  • $3 Economy Post* (3-7 days, no tracking)
  • FREE Pickup (Newcastle only)

Shipping costs may increase for heavy products or large orders.

Exact shipping can be calculated on the view cart page.

*Conditions apply, see shipping tab below.

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 and 38 cm lead screw, and we also have the stepper motor available without a lead screw.

Stepper motor with 28cm lead screw: bipolar, 200 steps/rev, 42×38mm, 2.8V, 1.7 A/phase.
When the nut is prevented from rotating, it travels up or down the rod as the motor rotates.


This linear positioning drive consists of Pololus 42×38 mm NEMA17 stepper motor 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 cm28 cm, and 38 cm.

NEMA 17-size stepper motors with 18, 28, and 38cm lead screws.

The included copper alloy traveling nut (also known as a carriage nut) features a mounting flange with four holes threaded for M3 screws. 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. We recommend the MP6500 stepper motor driver carrier or AMIS-30543 stepper motor driver carrier 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 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), we 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 we recommend using a bipolar stepper motor driver.

The JST XHP-4 connector that terminates the leads of the NEMA 17 stepper motor with 28cm lead screw.
Bipolar stepper motor wiring diagram.

Our NEMA 17 aluminum bracket offers a variety of options for mounting this stepper motor in your project:

NEMA 17 stepper motor with lead screw mounted with a stamped aluminum L-bracket.

Note: We can customize the shaft length for volume orders (at least a few dozen units). Please contact us for more information. While you might be tempted to cut the lead screw to shorter lengths yourself, this is something we advise against since the manufacturer specially treats the end of the lead screw to protect the nut.


  • 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 Ω 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 (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.


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, 282 mm for the stepper motor with 28cm lead screw, and 382 mm for the stepper motor with 38cm lead screw. 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.)

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

This product is listed in:

Documentation and Resources:
  • The Maker Revolution
  • The Maker Revolution celebrates the creation of new devices and the modification of existing ones - the transition from a consumer buying goods to eventually having a major part in their creation. The Maker Revolution places strong emphasis on free (...

Product Comments

Exact shipping can be calculated on the view cart page (no login required).

We deliver Australia-wide with these options:

  • $3 for Small Items (3-7 days, not tracked, only available on selected small items)
  • $6.95 for Standard Post (2-4 days, tracked)
  • $9.95 for Express Post (Overnight for most of Australia, 2+ days for rural, tracked)
  • Pickup - Free! Only available to customers who live in the Newcastle region (only after we email you to notify your order is ready)

International Orders - the following rates are for New Zealand and will vary for other countries:

  • $11.49 for Pack and Track (3+ days, tracked)
  • $16.50 for Express International (2-5 days, tracked)

If you order lots of gear, the postage amount might increment based on the weight of your order.

Our physical address (here's a PDF which includes other key business details):

Unit 18, 132 Garden Grove Parade
NSW, 2289

Take a look at our customer service page if you have other questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.

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