Bj42d15 26v10 Stepper Motor Datasheet ~repack~ May 2026

The BJ42D15-26V10 is a NEMA 17 hybrid stepper motor manufactured by Keli Motor Group. It is widely used as a stock component in Creality 3D printers, typically for the X, Y, or Z axes. Technical Specifications

The following data is compiled from manufacturer documentation and community-verified measurements for the BJ42D15 series: Step Angle: 1.8° (200 steps per revolution) Rated Current: 0.84 A per phase Phase Resistance: Approximately 5.9 Ω Holding Torque: ~0.4 N·m (approx. 2.86–4.0 kg·cm)

Rated Voltage: Usually 3.3V – 4.8V (calculated based on current and resistance), though it operates on 12V/24V systems via current-limiting drivers Frame Size: NEMA 17 (42 x 42 mm) Body Length: 34 mm Shaft Diameter: 5 mm ("D" shape) Weight: ~215g Key Operational Features Creality Ender 3 Stock Factory Vref · GitHub

The BJ42D15-26V10 is a high-precision, two-phase hybrid stepper motor widely utilized in CNC machinery, 3D printers, and medical instrumentation. This NEMA 17 motor is engineered for applications requiring high torque density and reliable positioning within a compact form factor.

This datasheet provides the essential technical specifications, wiring configurations, and performance characteristics for the BJ42D15-26V10. Technical Specifications

The following table summarizes the core mechanical and electrical ratings for this model. Specification Step Angle 1.8° (200 steps per revolution) Phase Count Rated Voltage Rated Current 1.5 A / Phase Phase Resistance 2.6 Ω ± 10% Phase Inductance 4.8 mH ± 20% Holding Torque 420 mN.m (approx. 60 oz-in) Detent Torque Rotor Inertia Insulation Class Class B (130°C) Weight Physical Dimensions

As a NEMA 17 frame size motor, the BJ42D15-26V10 adheres to standard mounting patterns, making it compatible with most off-the-shelf brackets and extrusions. Frame Size: 42.3mm x 42.3mm Body Length: 40mm (approximate)

Shaft Diameter: 5mm (usually "D-shape" for secure pulley mounting) Mounting Hole Pattern: 31mm x 31mm (using M3 screws) Wiring and Phase Configuration bj42d15 26v10 stepper motor datasheet

The BJ42D15-26V10 typically features a 4-wire bipolar configuration. Understanding the wire pairings is critical to prevent damage to your stepper driver. Standard Color Coding: Phase A: Black (A+) and Green (A-) Phase B: Red (B+) and Blue (B-)

Note: If the motor spins in the opposite direction of your software command, reversing the leads of a single phase (e.g., swapping Black and Green) will invert the rotation. Performance Characteristics

1. Precision and AccuracyWith a standard 1.8-degree step angle, the motor provides 200 physical steps per revolution. When paired with a microstepping driver (such as an A4988 or TMC2209) at 1/16 or 1/32 step resolution, the motor achieves exceptionally smooth motion and high positional accuracy.

2. Torque-Speed CurveLike all hybrid steppers, the torque of the BJ42D15-26V10 decreases as RPM increases. To maximize high-speed performance, it is recommended to use a higher input voltage to the driver (e.g., 12V or 24V), as this helps overcome the motor's back EMF.

3. Thermal ManagementUnder continuous 1.5A load, the motor body can become hot to the touch. This is normal for Class B insulation; however, ensuring adequate airflow or using the motor's aluminum mounting as a heat sink will extend the lifespan of the internal bearings. Recommended Applications

3D Printing: Ideal for X, Y, and E (extruder) axes due to its balance of weight and torque.

Desktop CNC: Suitable for light-duty milling and laser engraving. The BJ42D15-26V10 is a NEMA 17 hybrid stepper

Automation: Used in pick-and-place machines and automated lab equipment.

Robotics: Provides high holding torque for articulated robotic arms. Integration Tips

Driver Current Limiting: Always adjust the potentiometer on your stepper driver to match the motor's 1.5A rating. Exceeding this current will cause overheating and potential motor failure.

Microstepping: For quiet operation, use a driver with StealthChop technology.

Couplers: Use flexible jaw couplers when connecting to lead screws to account for minor shaft misalignments. If you'd like more specific information, please tell me: Specific driver you are using (e.g., TMC2209, A4988) Voltage of your power supply Mechanical load details (e.g., weight of the axis)

I can then provide custom wiring diagrams or calculate the required torque for your project.

Mechanical considerations

• Mounting: confirm faceplate dimensions and bolt pitch. Use proper flange screws and torque them per mechanical spec to avoid distortion.
• Shaft coupling: choose flexible couplers to tolerate slight misalignment and reduce bearing loads.
• Bearings & axial load: avoid excessive axial/radial loads on the shaft; use thrust bearings if axial loads are present.
• Thermal: motor will warm during continuous operation — ensure adequate ventilation or heat sinking. The winding temperature rating (from insulation class) determines safe continuous current and ambient limits.
• Vibration & resonance: small steppers can exhibit mid-speed resonance; add damping (mechanical or electrical microstepping, using dampers) or use slightly higher microstepping to smooth dynamic response.

BJ42D15-26V10 Stepper Motor — Datasheet Summary

Part 1: Decoding the Model Number: BJ42D15 26V10

Before diving into raw numbers, it is essential to understand what the alphanumeric code means. Manufacturers use these codes to encode physical and electrical traits. Mounting: confirm faceplate dimensions and bolt pitch

• BJ: This typically denotes the series or manufacturer code. "BJ" series motors are commonly produced by manufacturers like Changzhou BJ (China) or equivalent OEMs. It signifies a standard hybrid stepper motor.
• 42: This refers to the motor's faceplate size. In stepper motors, "42" indicates a 42mm x 42mm square flange. This is the industry-standard NEMA 17 mounting pattern.
• D15: This usually refers to the stack length or rotor length. "D15" likely signifies a 15mm deep rotor stack. In NEMA 17 motors, stack lengths range from 15mm up to 48mm. A 15mm stack indicates a compact motor, prioritizing length savings over extreme holding torque.
• 26V10: This is the most critical electrical parameter. It decodes to 2.6 Volts and 1.0 Ampere (per phase). The "V" often replaces a decimal in shorthand. Therefore, "26V10" translates to 2.6V / 1.0A.

Part 4: Performance Curves (Torque vs. Speed)

Datasheets typically provide a "Pull-out Torque" curve. For the BJ42D15 26V10, expect the following performance when driven at 24V with a microstepping driver:

• Holding Torque (Rated Current): ~0.22 N·m (22 N·cm or 31 oz·in). Note: This is lower than a standard NEMA 17 (usually 0.4 N·m) due to the short D15 stack.
• Detent Torque (Power off): ~0.012 N·m (The magnetic resistance felt when turning by hand).
• Maximum Speed (Practical): 3000 RPM (no load); 500 RPM (rated torque load).
• Torque at 500 PPS (1 rev/sec): ~0.20 N·m.
• Torque at 1000 PPS (2 rev/sec): ~0.12 N·m.

Application Warning: Because this is a low-voltage, low-current motor (1A), it is designed for low-speed, high-precision tasks. Trying to exceed 800 RPM with a load will cause the motor to stall.

Part 7: Comparison with Similar NEMA 17 Motors

Why choose the BJ42D15 26V10 over other NEMA 17s?

| Model | Current | Voltage | Torque | Best For | | :--- | :--- | :--- | :--- | :--- | | BJ42D15 26V10 | 1.0A | 2.6V | 0.22 N·m | Battery-powered devices, small extruders | | Standard NEMA 17 | 1.5A | 3.0V | 0.40 N·m | General 3D printing (Ender 3) | | High Torque NEMA 17 | 2.0A | 3.6V | 0.55 N·m | CNC, Laser engravers | | BJ42D47 (Long) | 1.8A | 4.0V | 0.48 N·m | Heavy Z-axis lifts |

Verdict: The BJ42D15 sacrifices torque for low heat generation and low current draw. It is ideal for single-board electronics where your motor driver cannot handle 1.5A+.

1. L/R Drive (Simple, but Hot)

Use power resistors in series with a higher voltage supply. For 26V operation, drive directly. For 12V operation, you need no resistors (since 26 Ohms limits current to 0.46A on 12V – safe but low torque).

Typical pinout (4-lead bipolar)

• A+: Coil A end 1
• A-: Coil A end 2
• B+: Coil B end 1
• B-: Coil B end 2