Review on High-Performance Longruner 5X Geared Stepper Motor 28byj 48 Uln2003 - Complete with Uln2003 Driver Board for ArduinoIDE (Wireless Connection) by Douglas Holla

These little steppers work great. You can easily convert them to bipolar mode by removing the blue cover and cutting the center trace of the PCB. I needed small powerful bipolar steppers for a robot project I am building with my daughter for school and they fit all the needs perfectly with a little modification. After the mid lane was cut out, a quick YouTube search showed how to connect it to a conventional bipolar stepper motor driver. At 12v the motors get hot and produce enough torque to damage the internal gears. The gearing has little to no backlash, and the pitch feels tight and precise.