3329_0 42STH38 NEMA-17 Bipolar Stepper with 99.51:1 Gearbox

£66.59 £55.49

This NEMA-17 motor has an integrated Planetary gearbox with a 991044/2057 :1 ratio.It comes with the rear shaft exposed, so you can mount an encoder or shaft coupler.

This bipolar stepper with a rear shaft and a planetary gearbox has a 0.018° step angle and 48 kg·cm of torque at low speeds.


When connected to a 1067 - PhidgetStepper Bipolar HC, the 3329 has a maximum speed of 34 RPM. At the output of the gearbox, the step angle is approximately 0.018°. When using the step angle in calculations, you should derive the exact step angle by dividing 1.8° by the gearbox reduction ratio. At 1.7 Amps, this gearbox stepper can produce a maximum torque of 250 kg-cm. However, the gearbox is only rated for 48 kg-cm of continuous torque, and 100 kg-cm for brief overloads. Loading this gearbox stepper beyond the torque rating of the gearbox will shorten its useful life.

The mounting holes on this motor are compatible with the 3338 nema 17 mounting bracket. The 3329 stepper motor connects to a bipolar motor controller such as the 1067 - PhidgetStepper Bipolar HC.

The following diagram 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.

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

Mechanical Drawing

Motor Properties

Motor TypeBipolar Stepper
Manufacturer Part Number42STH38-1684B / 36JXS60K99.51
Step Angle0.018°
Step Accuracy± 5 %
Holding Torque48 kg·cm
Rated Torque48 kg·cm
Maximum Speed (w/1067 Motor Controller)34 RPM
Acceleration at Max Speed
(w/1067 Motor Controller)
1.2E+06 1/16 steps/sec²

Electrical Properties

Recommended Voltage12 V DC
Rated Current1.7 A
Coil Resistance1.7 Ω
Phase Inductance3.2 H

Physical Properties

Shaft Diameter8 mm
Rear Shaft Diameter3.9 mm
Mounting Plate SizeNEMA - 17
Weight564 g
Number of Leads4
Wire Length300 mm

Gearbox Properties

Gearbox TypePlanetary
Gear Ratio99 10442057 : 1
Backlash Error1 12°
Maximum Strength of Gears48 kg·cm
Shaft Maximum Axial Load49.1 N
Shaft Maximum Radial Load98.1 N