GM31 Step Motor

Motor Step Angle: 7,5°, full step
Number of Phase: 2, bipolar
Insulation resistance: 100 MΩ, 500Vdc
Insulation class: E
Coil Resistance/Induction: 7,5Ω/10mH
Max temp. (motor housing): 60 °C
Racc. temp (motor housing): 35-45 °C

Nominal voltage: 12V
Voltage driver: 3,75 – 36V
Max axial/radial shaft load: 5N/20N
Max allow torque: 50 Ncm
Max current (continuous): 250 mA
Max current (non-contin.): 500 mA
Operating temp.: -20 °C/+65 °C


Type	Ratio To:1	Length (mm)	Holding Tourqe (mNm)	Max Speed (rpm)
GM31-12-35	12.25	35	600	122
GM31-21-35	21.14	35	800	71
GM31-36-35	35.73	35	800	42
GM31-72-35	71.54	35	800	21
GM31-149-35	149.05	35	800	10
GM31-208-35	208.66	35	800	7
GM31-608-35	608.61	35	800	2.5
GM31-1470-35	1470.82	35	800	1

Stepper Gearmotor Driver Available

The step-motor is a synchronous electric motor with pulsed direct current and brushless electronic control which can divide its rotation into a large number of steps. Unlike brush DC motors, the position of the motor can be accurately controlled without an encoder (feedback).

The GM31 series is a compact and precise stepper gearmotor designed for applications requiring accurate positioning, stable torque, and smooth low-speed operation. By combining a 2-phase bipolar stepper motor with a gearbox offering ratios from 12:1 up to 1470:1, the GM31 delivers exceptional holding torque and reliable performance in a very compact 35 mm housing length.

Technical Highlights

Motor type: 2-phase bipolar stepper motor
Nominal voltage: 12 V (driver range 3.75 – 36 V)
Coil resistance/induction: 7.5 Ω / 10 mH
Insulation class: E
Insulation resistance: 100 MΩ at 500 VDC
Maximum housing temperature: 60 °C (recommended 35–45 °C)
Operating temperature range: –20 °C to +65 °C
Shaft loads: up to 5 N axial, 20 N radial
Maximum torque: 50 Ncm
Continuous current: 250 mA (500 mA peak)

Gearbox Options

The GM31 is available with a wide selection of reduction ratios to suit different torque and speed requirements:

Model	Ratio	Length (mm)	Holding Torque (mNm)	Max Speed (rpm)
GM31-12-35	12:1	35	600	122
GM31-21-35	21:1	35	800	71
GM31-36-35	36:1	35	800	42
GM31-72-35	72:1	35	800	21
GM31-149-35	149:1	35	800	10
GM31-208-35	208:1	35	800	7
GM31-608-35	609:1	35	800	2.5
GM31-1470-35	1471:1	35	800	1

This range allows the GM31 to be configured for either higher speed with moderate torque, or extremely high torque with ultra-low speed for positioning tasks.

Advantages

High precision: Step resolution allows accurate positioning without encoders.
Compact design: Only 35 mm long, ideal for tight installations.
Stable holding torque: Up to 800 mNm, maintaining position even without continuous motion.
Wide operating range: Works in challenging environments from –20 °C to +65 °C.
Durable construction: Designed to handle axial and radial shaft loads in light-to-medium duty applications.

Suggested Applications

Automation & Robotics
- Small robotic joints, grippers, and motion modules requiring precise control.
Laboratory & Medical Equipment
- Sample handling systems, microfluidics, pumps, and small diagnostic machines.
Optical & Imaging Systems
- Camera positioning, filter wheels, and pan/tilt modules with slow, accurate rotation.
Industrial Instrumentation
- Valve actuators, dosing units, labelers, and inspection tools.
Consumer & Specialty Devices
- Vending mechanisms, small CNC positioning systems, and educational robotics kits.

The GM31 Step Motor with Gearbox delivers precise motion control in a compact package, with torque and speed options tailored by a wide range of gearbox ratios. Its ability to provide accurate positioning without encoders, combined with high holding torque and long-term reliability, makes it an excellent choice for engineers designing automation, medical, laboratory, and light-industrial systems.