LDO NEMA 17 MOTOR LDO-42STH48-2504AC (DFH)

High-torque 48mm LDO NEMA 17 stepper for CoreXY motion systems. LDO's official LDO-42STH48-2504AC spec identifies this as a 2-phase, 1.8° stepper rated at 2.5A/phase with 0.55 N·m holding torque and a 48mm body.

Why use this motor

• More torque than a short NEMA 17: the 48mm body and 0.55 N·m holding torque make it a good fit for higher-load printer motion axes.
• Standard printer ecosystem fit: 5mm shaft, 4-lead wiring, and NEMA 17 mounting make it easy to pair with common pulleys and stepper drivers.
• LDO part-number grounded: manufacturer model LDO-42STH48-2504AC; this part is also commonly sold as 42STH47-2504AC.

Specifications

• Manufacturer / MPN: LDO LDO-42STH48-2504AC
• Motor type: 2-phase NEMA 17 stepper motor
• Step angle: 1.8° ± 5%
• Rated voltage: 3.0V/phase
• Rated current: 2.5A/phase
• Phase resistance: 1.2Ω ± 20%
• Phase inductance: 1.5mH ± 20%
• Holding torque: 0.55 N·m / 5.5 kgf·cm
• Body length: 48mm
• Approximate weight: 0.35kg
• Leads: 4
• Insulation class: Class B, 130°C

Fitment and pairings

• Useful for Mercury One.1 / Zero G-style CoreXY motion work; pair it with the Zero G Mercury One.1 Motion Kit if you are building that conversion.
• For a typical 5mm-shaft belt drive, match it with a 20T 5mm-bore pulley and compatible GT2 belt.
• Drive it with a properly configured stepper driver such as the BTT TMC2209 v1.2 Stepper Driver; set current from your controller and printer configuration, not from the product page alone.

Gotchas

• This is the AC model, not the high-temperature AH variant.
• Confirm shaft length, connector, and cable routing against your printed parts before ordering for a non-Mercury/non-Voron build.