What is NEMA?

[eeguy]

Hi, I came across some projects that use NEMA 17 or NEMA 23 motors. What does NEMA mean? Is it a some kind of standard to distinguish among motors of different sizes?

[DimitriP]

Yes!

[Veteran68]

With the handle 'eeguy' and based in US, I have to believe you know what NEMA is?

As to why stepper motors are referred to in NEMA terms: https://reprap.org/wiki/NEMA_Motor

The US-based National Electrical Manufacturers Association creates standards that are developed by the manufacturers through a voluntary consensus to provide descriptions of how things should be. NEMA ICS 16-2001 (Motion/Position Control Motors, Controls, and Feedback Devices) describes stepper motors and is the NEMA standard usually referred to when talking about the NEMA standard in the context of RepRap, stepper motors and 3D printers.

In section 4.3.1.1 of that standard, NEMA chose to label stepper motors (e.g. "NEMA 17") with the size of their faceplate in tenth of inches. So a "NEMA 17" has a 1.7 inch by 1.7 inch faceplate. By standardizing the stepper motors (the faceplates, flanges and screw holes), you know ahead of time that one NEMA 17 motor will fit into the mounts of another NEMA 17 without having to redesign anything. This makes swapping components easier.

The first working RepRap used NEMA 23 Stepper motors for positioning and a different kind of motor for the extruder. As of 2013, most RepRap designs call for NEMA 17 Stepper motors or NEMA 14 Stepper motors for both positioning and extruding.

[DimitriP]

So...still "Yes".

[xrunner]

Hi, I came across some projects that use NEMA 17 or NEMA 23 motors. What does NEMA mean? Is it a some kind of standard to distinguish among motors of different sizes?

 

https://www.nema.org/about

 

 

[MarkT]

Its actually less work to ask a search engine this than a forum, and the answer comes back quicker...

[drago462]

NEMA 17 refers to it having a 1.7" x 1.7" frame.

[beanflying]

Like all standards it has also been bastardized so pick an item with care in particular when it comes to the shaft dimension and if it is metric or imperial and is the key 'standard' or 'special'

In theory as others stated it 'generally' means frame size but there is a huge level of variations from there. Take a glance here and do a search for hybrid nema 17 steppers there is dozens to filter down https://www.omc-stepperonline.com/hybrid-stepper-motor?mfp=184-frame-size-mm[Nema%2017%20(42%20x%2042)]

[MarkT]

BTW standard NEMA sizes for steppers are 8,11,14,17,23,34,42