OMC 17HE08-1004S Nema 17 Bipolar 1.8deg 17Ncm

The 17HE08-1004S is the recommended Bill-of-Materials stepper for the EMU (Expandable Multi-material Unit) — the modular, dry-box MMU built around the proven Filamentalist V3 platform. The EMU drives each lane with one of these compact Nema 17 motors, so the quantity you need scales with your build: two for a dual-lane endless-spool setup, five for a five-lane multi-material unit, and so on.

It’s specified in the official EMU BOM as the primary motor for the filament-driving assembly, paired with the BMG hobbed gear that grips your filament. We supply the genuine OMC-StepperOnline part, in UK stock.

Why it’s the right motor for an EMU lane

• Compact 42×42×23 mm body — the short 23 mm frame tucks neatly inside the sealed dry box next to the Filamentalist rewinder, keeping every lane fully self-contained.
• Low 1.0 A rated current — runs cool, which matters when the unit sits on top of (or beside) a hot printer. Easy on the per-lane driver whether you use the Solo Lane Board (SLB) or an EBB42 / EBB36.
• Ø5 mm D-cut shaft — keys straight onto the BMG hobbed gear with a grub screw, no machining needed.
• 1.8° step angle (200 full steps/rev), 4-wire bipolar — fully supported by Klipper + Happy Hare, the EMU’s control stack, and quiet on TMC drivers.
• 1 m pre-attached leads — comfortable reach to the lane board inside the dry box.

Building a multi-lane EMU? You need one motor per lane. Add the matching quantity to your basket — tiered pricing applies as you scale up.

Beyond the EMU

Outside multi-material builds, the 17HE08-1004S is an excellent compact, current-friendly Nema 17 for 3D-printer extruders, lightweight or auxiliary axes, and general CNC and robotics projects. Its standard 42 mm face bolts to any Nema 17 mount or bracket, and the D-cut shaft accepts common GT2 16T/20T pulleys as well as extruder gears.

Specifications

Datasheet

Wiring & connection

This is a 4-wire bipolar motor with two coils — Phase A and Phase B. Wire each coil pair to the matching A/B output on your stepper driver (SLB, EBB42/36 or other Klipper board). The lead colours follow the standard StepperOnline scheme:

To reverse the direction of rotation, swap the two wires of a single coil (e.g. A+ and A−), or simply invert the motor in firmware.