LDO-42STH20-1004ASH NEMA17 Super-Slim HT Stepper Motor for Voron AB Extruder

The LDO-42STH20-1004ASH2 is a compact 1.8° NEMA17 Super-Slim HT stepper motor designed for Voron V1 & V2 Afterburner-style extruder applications. Featuring a short 20–21mm body, 1.0A phase current, and 18N·cm holding torque, it delivers reliable extrusion control while keeping toolhead mass low.

Built with Class H 180°C insulation and UL1332 24AWG 200°C Teflon wire, this motor is well suited for enclosed 3D printers and high-temperature printing environments where heat resistance and stable motion are essential.

Key Features

Super-Slim 20mm NEMA17 Body

The short motor body helps reduce toolhead weight and improves fitment in compact extruder assemblies. It is a practical choice for Voron Afterburner-style builds where space and moving mass are critical.

18N·cm Holding Torque

With 1.8kgf·cm / 18N·cm holding torque, this motor provides enough torque for geared extruder setups while maintaining a compact form factor.

High-Temperature Construction

The motor uses Class H 180°C insulation and 200°C-rated Teflon wire, making it suitable for enclosed 3D printers and heated chamber applications.

Pre-Wired XH2.54 Connector

Comes with a 100±5mm twisted 4-wire lead and JST XH2.54-4P connector, simplifying installation for compatible toolhead wiring layouts.

This motor is designed for:

Voron V1 & V2 Afterburner extruder motor position

Voron AB-style extruder assemblies

Compact geared extruder setups requiring a 20mm NEMA17 pancake stepper

Applications requiring Ø5mm D-shaft, 31mm NEMA17 mounting pattern, and short 100mm motor lead

Fitment note: If used outside the Voron AB extruder position, confirm compatibility before installation – pay special attention to shaft length, gear position, connector orientation, and cable routing.

Installation Notes

Configure driver current - Use a stepper driver set to 1.0A phase current (or lower, as required by your printer setup).

Verify coil pairs - Confirm coil wiring before powering the motor if using a custom harness or non-standard control board.

Check extruder gear compatibility - Ensure the extruder gear or pulley matches the Ø5mm D-cut shaft.

Handle the connector carefully - Do not force the connection; verify JST XH2.54-4P pin orientation before installation.

Route cables for Voron AB builds - Confirm cable routing to avoid wire strain during toolhead movement.

1 × LDO-42STH20-1004ASH