This Nema 23 size stepper motor is equipped with MG series high precision gearbox. The gear ratio is 50:1 and the Max. backlash is 50 arc minutes. It's an excellent choice for applications that require good accuracy but low cost.
As MG series gearbox built-in shaft coupling, so you can change the motor or gearbox easily.

Electrical Specification

Manufacturer Part Number: 23HS30-2904S-MG50
Motor Type: Bipolar Stepper
Holding Torque without Gearbox: 1.89Nm(267.65oz.in)
Rated Current/phase: 2.9A
Phase Resistance: 1.13ohms
Inductance: 4.8mH±20%(1KHz)
Insulation Class: B 130°C[266°F]

Gearbox Specifications

Gearbox Type: MG Planetary
Gear Ratio: 50:1
Efficiency: 90%
Backlash at No-load:≤50arcmin
Max.Permissible Torque: 20Nm(221.27lb-in)
Noise: ≤60dB
Waterproof Rating: IP54
Lifetime: 20000hours

Physical Specification

Frame Size: 57 x 57mm
Motor Length: 76.5mm
Gearbox Length: 68mm
Output Shaft Type: Key way
Output Shaft Diameter: Φ14mm
Output Shaft Length: 34mm

Connection

A+: Black, A-: Green, B+: Red, B-: Blue