This stepper motor is a strong choice for any project.

5 motors needed for Prusa Mendel.
4 needed for OG Mendel.

Specifications:

• Model number:  1124090
• Holding Torque:  5.5Kg.cm
• Rated Voltage:  4.2V
• NO.of Phase:  2
• Step Angle:  1.8° ± 5%
• Resistance Per Phase:  2.8Ω± 10%
• Inductance Per Phase:  4.8mH± 20%
• Current Per Phase:  1.5A
• Shaft:  5mm diameter w/ one flat
• Insulation Class:  Class B
• Dielectric Strength:  100Mohm
• Operation Temp Range:  -20 ~ +40° C
• Lead Wire:  22AWG / 750mm

See datasheet below.