Amazon.com: STEPPERONLINE Nema 8 Bipolar Smallest Stepper Motor 1.6Ncm/2.3oz.in 1.8deg 28mm 0.2A 4 Leads : Industrial & Scientific
NEMA 23 High Torque Stepper Motor, 1.8°, 4 or 8 Wires
Amazon.com: Twotrees Stepper Motor Nema 17 Motor High Torque 1.5A (17HS4401) 42N.cm (60oz.in) 1.8 Degree 38MM 4-Lead with 1m Cable and Connector for 3D Printer : Industrial & Scientific