What is it?

For a bargain price of just $12 (plus shipping), discover the untapped potential of two reclaimed 17PM-J342 variant stepper motors, harvested from retired document scanners, and breathe new life into these steppers with enhanced precision and reliability. This listing also comes with a specifically-made custom breakout board featuring the high-performance A3988 stepper driver IC. The A3988 stepper driver IC allows you to achieve (1/2 or 1/4) micro-stepping, breaking down each step of the stepper motors into smaller increments. This results in smoother motion, reduced vibrations, and increased positional accuracy.

Stepper Motor Specifications

• Type: Bipolar
• Step Angle: 1.8 degrees (200 steps per revolution)
• Rated Current: 0.9A
• Resistance: 4 ohms
• Holding Torque: 260 mNm
• Inductance: 9.7 mH
• Rotor Inertia: 35 g*cm^2
• Detent Torque: 7.9 mNm

One stepper motor has a 12.5cm cable while the other has a longer 40cm cable. They also have slightly different gears attached to the shafts (see pictures above). Each motor requires 6 GPIO pins from your microcontroller. For example:

• Motor 1: I01, I11, PHASE_1, I02, I12, PHASE_2
• Motor 2: I03, I13, PHASE_3, I04, I14, PHASE_4

NOTE: To use it, you will also need a 24V (2.5A or higher-rated) power adapter which is NOT included in this listing.

The AS3988 Stepper Driver board has the following pinouts:

top row

• GND
• I12 (Motor 1 Control Signal)
• I02 (Motor 1 Control Signal)
• PH2 (Motor 1 Phase Signal)
• I11 (Motor 1 Control Signal)
• I01 (Motor 1 Control Signal)
• PH1 (Motor 1 Phase Signal)
• VCC (3.3V-5V)

bottom row

• GND
• I14 (Motor 2 Control Signal)
• I04 (Motor 2 Control Signal)
• PH4 (Motor 2 Phase Signal)
• I13 (Motor 2 Control Signal)
• I03 (Motor 2 Control Signal)
• PH3 (Motor 2 Phase Signal)
• VMOT (24V supply for stepper motors)

For software, you can use the open source Arduino library we wrote: A3988

Potential Use Cases

• 3D Printing: Stepper motors are widely used in 3D printers to control the movement of the print head and build platform, ensuring precise layer-by-layer deposition of material.

• CNC Machines: Stepper motors play a crucial role in computer numerical control (CNC) machines, where they drive the motion of the cutting tool or workpiece platform with high accuracy for tasks like milling, engraving, and routing.

• Robotics: Stepper motors are commonly used in robotics for controlling the movement of robot arms, joints, and various components, allowing robots to perform tasks with precision and repeatability.

• Camera and Gimbal Stabilization: Stepper motors are used in camera gimbals and stabilization systems to ensure smooth and stable camera movement, resulting in steady and shake-free footage.

• Automated Systems: Stepper motors are essential in automated systems, including conveyor belts, pick-and-place machines, and packaging equipment, where they control the movement of components or products with high accuracy.

• Telescopes and Astronomy: Stepper motors are used in telescope mounts to precisely track celestial objects as they move across the sky, enabling astronomers to capture long-exposure images.