NEMA Specifications and Torque Ratings for 3D Printer
Stepper motors are relatively simple mechanisms: A series of electromagnetic coils are activated in a specific sequence to spin a motor shaft a precise number of degrees. The NEMA specification is what allows stepper motors to be identified, and references the size of the faceplate of the motor.
Most 3D printers utilize NEMA 17 stepper motors. There are many popular variations, each having different physical qualities suitable for different applications. These are primarily distinguished by torque rating, in Newton Centimeters (N⋅cm).
The three popular varieties tend to be around 20-25 N⋅cm, 40-45 N⋅cm, and 50-56 N⋅cm. The motors in the first range are generally called “pancake motors”, while the 40-45 N⋅cm variations are considered “standard” and the final set “high torque”.
Below, we’ve assembled a list of uses for each variation, which should help you choose the best motor for your needs. Finally, the last section briefly discussed how to install a stepper motor. (nema 17 planetary gearbox)