Products for USB Sensing and Control
Products for USB Sensing and Control

42BYGH40(M)-160-4A NEMA 17 Bipolar 26.85:1 Planetary Gearbox Stepper

ID: 3318_0

This bipolar stepper with planetary gearbox has a 0.067° step angle and 30 kg·cm of torque at low speeds.


Replaced by the 3318_1 - 42STH38-1684A NEMA 17 Bipolar 26.85:1 Planetary Gearbox Stepper.

This NEMA-17 motor has an integrated Planetary gearbox with a 26 103/121 :1 ratio. At 1.6 Amps (maximum current), this gearbox stepper can produce a maximum torque of 77 kg-cm. The gearbox is only rated for 30 kg-cm of continuous torque, and 60 kg-cm for brief overloads. Loading this gearbox stepper beyond the torque rating of the gearbox will shorten its useful life.

When connected to a 1063 - PhidgetStepper Bipolar 1-Motor, the 3318 has a maximum speed of a little under 23 RPM. At the output of the gearbox, the step angle is a little under 0.07°. When using the step angle in calculations, you should derive the exact step angle by dividing 1.8° by the gearbox reduction ratio.

Product Specifications

Motor Properties
Motor Type Bipolar Stepper
Step Angle 0.067°
Step Accuracy 5 %
Holding Torque 30 kg·cm
Rated Torque 30 kg·cm
Rated Speed 22 RPM
Electrical Properties
Recommended Voltage 12 V DC
Rated Current 1.6 A
Coil Resistance 1.7 Ω
Phase Inductance 3.2 mH
Physical Properties
Shaft Diameter 8 mm
Mounting Plate Size NEMA - 17
Weight 513 g
Number of Leads 4
Gearbox Properties
Gearbox Type Planetary
Gear Ratio 26 103121 : 1
Maximum Strength of Gears 30 kg·cm
Gearbox Efficiency 80 %
Shaft Maximum Axial Load 49.1 N
Shaft Maximum Radial Load 98.1 N
Customs Information
Canadian HS Export Code 8501.10.00
American HTS Import Code 8501.10.40.60
Country of Origin CN (China)

The 3318 stepper motor connects to the 1063 - PhidgetStepper Bipolar 1-Motor.

The following table shows how to connect the motor wires to the board connectors to produce a clockwise rotation in the stepper motor when increasing position. To wire for counter-clockwise rotation when increasing position, reverse the red and blue wires.

Wire Color Black Green Red Blue
Board Connector A B C D

Note: Make sure to unplug the power cord from the motor controller before switching wires around.


warning Connecting the motor directly to a power supply will destroy the motor and void the warranty. If you want to check your motor make sure it is connected to a constant current / chopper drive controller.