NEMA 17 Stepper Motor 4.2kg-cm 1.8° Single D-Shaft

Specifications:

• Motor Type: Bipolar Hybrid Stepper

• Frame Size: NEMA 17 (42mm × 42mm)

• Motor Length (without shaft): 40mm

• Step Angle: 1.8° (200 steps per revolution)

• Holding Torque: 4.2 kg-cm (420 mN.m / ~60 oz-in)

• Rated Current: 1.6A per phase

• Rated Voltage: 2.5V - 3.0V DC (Nominal coil voltage)

• Phase Resistance: 1.6 Ω

• Phase Inductance: 3.0 mH

• Number of Phases: 2

• Shaft Type: D-Shaft (Single Shaft)

• Shaft Length: 23mm

• Shaft Diameter: 5mm

• Weight: 0.30 kg (300g)

• Connection Terminal: 6-pin socket(uses 4 pins for bipolar operation).

Project Evolution

• Past Projects: If you've previously built lightweight projects using basic DC gear motors or the small 28BYJ-48 stepper motors, you've likely hit their mechanical limits quickly. They struggle under the weight of heavier 3D printer carriages, slip during fast directional changes, and simply lack the holding torque needed to keep a loaded robotic arm securely positioned.
• The Upgrade Unlock: Upgrading to this 4.2kg-cm NEMA 17 motor fundamentally changes the scale of what you can build. With a substantial 4.2 kg-cm (420 mN.m) of holding torque and a standard 1.8° step angle, it can aggressively drive lead screws and timing belts without missing steps. It is the industry-standard choice for X and Y axes on custom CNC routers, heavy-duty 3D printer extruders, and automated camera sliders.
• Effort Level & Minimum Hardware: Intermediate: Getting this motor spinning requires a basic understanding of stepper drivers and power management. You cannot power this directly from the pins of an Arduino or Raspberry Pi. You will need a dedicated constant-current stepper motor driver (like the A4988 or DRV8825) and an external power supply capable of delivering at least 1.6A per motor.

Virtual Technician & Wiring Guide

This motor features a 6-pin female connector housing, but as a bipolar stepper, it only uses 4 of those pins to power its two internal coils (Coil A and Coil B).

⚠️ CRITICAL WARNING: Never connect or disconnect the stepper motor wires from your driver board while the power supply is turned on. Doing so will create a massive voltage spike that instantly destroys the stepper driver chip. Always power down completely before adjusting wires.

Determining Your Coil Pairs: 

1. Probe the pins on the connector cable you attach to the motor.

2. When the multimeter beeps, you have found the two wires belonging to Coil A.

3. The remaining two wires that beep together belong to Coil B.

Required Additional Items:

• Stepper Motor Driver (A4988, DRV8825, or TMC2209) — required to translate logic signals from your microcontroller into the high-current power the motor needs.

• Microcontroller (Arduino Uno, Mega, or ESP32) — to generate the high/low STEP and DIR control signals.

• External Power Supply (12V or 24V DC, minimum 2A per motor) — to provide the necessary voltage to drive the motor coils efficiently.

Recommended Add-ons:

• NEMA 17 L-Bracket Mount — for rigid, 90-degree mounting to your chassis or aluminum extrusion.

• 5mm to 8mm Shaft Coupler (Flexible) — to connect the motor's 5mm D-shaft to standard 8mm lead screws used in CNC builds.

• NEMA 17 Vibration Dampers — to significantly reduce operating noise and resonance in sensitive builds like 3D printers.

Package Includes:

• 1× NEMA 17 Stepper Motor 4.2kg-cm 1.8° Single D-Shaft

Frequently Asked Questions

Q1: Is this 4.2kg-cm NEMA 17 compatible with Arduino Uno? Yes, it is fully compatible with an Arduino Uno, but you cannot connect it directly to the GPIO pins. You must use a dedicated stepper motor driver (like the A4988 or DRV8825) between the Arduino and the motor.

Q2: Can I use this motor with a Raspberry Pi? Yes, the motor works perfectly for Raspberry Pi projects. Since the Pi outputs 3.3V logic, simply ensure your chosen stepper motor driver supports 3.3V logic signals on its STEP and DIR pins.

Q3: Is this motor suitable for a 3D printer extruder? Absolutely. The 4.2kg-cm holding torque makes it ideal for direct drive extruders or heavy X/Y axes where skipping steps would ruin a long print.

Q4: Does this work with an L298N motor driver? While technically possible, using an L298N is highly discouraged for this stepper motor. You should use a constant-current stepper driver (like the A4988) to maintain optimal torque and prevent the motor from overheating.

Q5: What voltage does this stepper motor require? This motor is designed to be driven by a constant-current stepper driver powered by a 12V to 24V DC power supply. Higher voltages allow the driver to push current into the coils faster, giving you better high-speed performance.

Q6: How much current does this NEMA 17 draw? This specific high-torque model is rated for 1.6A per phase. You must adjust the VREF potentiometer on your stepper motor driver to match this limit to prevent damaging the motor or the driver.

Q7: Can I power this directly from my Arduino's 5V or Vin pin? No. Drawing stepper motor power from an Arduino will instantly overload the board's voltage regulator and destroy the Arduino. Always use a separate external power supply (e.g., 12V 2A) wired directly to your motor driver.

Q8: The connector has 6 pins, how many wires do I actually need? You only need 4 wires. This is a bipolar stepper motor, so it only uses 4 of the 6 pins in the socket to power its two internal coils (Coil A and Coil B).

Q9: How do I find the coil pairs on this bare motor? Use a digital multimeter set to continuity mode (beep mode) and probe the wire ends of the connector cable you attach. The two wires that cause the multimeter to beep form a single continuous coil pair.

Q10: Do I need a capacitor for the motor driver? Yes, it is strictly required to place a 100µF (minimum 35V) electrolytic capacitor across the VMOT and GND pins on your stepper driver. This protects the driver from destructive voltage spikes.

Q11: Can I use standard Dupont jumper wires to connect the motor? No, standard male-to-female jumper wires will not securely fit the 6-pin socket on the motor. You need a proper 6-pin JST-PH (or similar) to 4-pin stepper motor cable designed specifically for NEMA 17 motors.

Q12: Which Arduino library should I use for this motor? The "AccelStepper" library is highly recommended. It handles the complex math required for smooth acceleration and deceleration, preventing the motor from stalling during rapid movements under load.

Q13: How many steps per revolution does this motor have? With a 1.8° step angle, this motor requires exactly 200 full steps to complete one 360-degree revolution. You can increase this resolution using micro-stepping on your driver (e.g., 1/16th stepping).

Q14: Why is my NEMA 17 motor just vibrating and not spinning? Vibration without rotation almost always means one of the motor coils is wired incorrectly. Check your wiring with a multimeter to ensure you haven't accidentally crossed a wire from Coil A with a wire from Coil B.

Q15: Why is the motor getting extremely hot to the touch? Stepper motors naturally run warm (up to 80°C is safe), but if it is burning hot, your driver is supplying too much current. Use a multimeter and a ceramic screwdriver to lower the VREF adjustment on your driver to match the motor's 1.6A rating.

Q16: Why is my motor skipping steps when moving fast? Skipping steps usually occurs if you are accelerating the motor too quickly in your code, attempting to move a mechanical load that exceeds its 4.2kg-cm torque, or using a power supply voltage (like 9V) that is too low to maintain high-speed torque.

Q17: My A4988 driver burned out instantly, what happened? You likely unplugged or plugged in the stepper motor wires while the power supply was turned on. Connecting or disconnecting a stepper motor while powered instantly fries the driver IC.

Q18: Does Probots sell this 4.2kg-cm motor in bulk for institutional orders? Yes, we supply these high-torque stepper motors in bulk for manufacturing lines, CNC builders, and engineering colleges. Please contact our sales team for volume pricing.

Q19: Is the motor on Probots the genuine version or a cheap clone? Every stepper motor we stock is Probots™ ProSpec Grade. We strictly source and visually verify these bare motors to ensure they meet genuine datasheet specifications for holding torque and internal coil resistance.

Q20: Does Probots provide technical support for this NEMA 17 motor after purchase? Yes, our Bangalore-based engineering team is available to assist you. If you are struggling with driver wiring, identifying coil pairs, or debugging your Arduino code, we can help you get your build moving safely.