Absolute Unit Of A Stepper Motor!

Behold, the humble stepper motor, in what in this case is called the NEMA23 package, where "NEMA" is the National Electrical Manufacturers Association, which is a trade association that has helped define some standards for electrical equipment, and "23" is a 2.3 inche square mounting plate size, or 58.4mm square if you're in just about anywhere else aside from the US. It's a bigger beefier version of the NEMA17 stepper motor commonly used in many 3D printers, and NEMA23 steppers do show up in bigger 3D printers.

This particular one has a holding torque rating of 166 oz-in or 1.1 n-m. Stepper motors are precision devices but not super-strong - they're most commonly rated by "holding torque," which is the rotational load the motor can keep still without allowing movement. The torque limits for for when it can start spinning from a standstill without stalling out, and when it stalls out under load and makes some interesting noises (or, pull-in and pull-out tqrque limits, respectively) are affected by target speed, drive voltage/current, stepping method, acceleration/deceleration, and a few other things, but is usually listed on charts called torque curves. As a general rule, most steppers of this size class can only "do" about a tenth of their holding torque at their full rated speed.

This rite cheer is fairly typical in size for a NEMA23. However, I needed something a little bit more, well, I would say "stronger" but "more stronger" is just not right.

of a stepper motor

So let's go with "more stronger" anyway. Say "hello" to the NEMA34 high-torque extended-length stepper motor.

Big boy there is a slower speed motor, 300 RPM, but eats up to 60 volts at 6 amps per coil and produces a metric boatload of torque. Its holding torque rating is 13 newton-meters or about 10 pound-feet, and it'll easily do over a quarter of that while spinning. (Its pull-out torque is over 4n-m @ 300 RPM!) This might not sound like much but two of these can move the 75Kg+ gantry of a giant 3+-meter-wide CNC welding machine like it's nothing. The big one can spin about four times harder than the small one can resist.

Little versus not-so-little. Oh, also, chongus here weighs over 6 kilograms.