Hi! I just started researching about Servo Motors to learn what is available on the market, but when I try to search in stores they sometimes get mixed up with stepper motors so it's a little bit confusing.
Do servo motors sizing follow the same standard as stepper motors? i.e. NEMA 17, NEMA 24
or is there another way of categorizing servos?
Anyone has a reommendation to a blog that describes things for dummies? 
Thank you.
NEMA XX describes a mechanical face. If that is used for other motors than steppers, I can't tell for sure.
If You find data like "bipolar", angle it's a stepper.
Another common confusement is between servo and servo motor. 2 completely different things.
I've read things like servo-step and stuff like that, which makes it more confusing.
I didin't know about the difference about servo and servomotors. That's probably why I got so many different results from one search to another.
Thank you for the link , it is very helpful. But that's not the kind of motor I'm looking for
Since I'm looking into replacing stepper motors
, is there any servo or servomotor that has the same face as a stepper motor NEMA 17?
The length of the motor doesn't matter, but the distance between the holes has to be similar if possible. Is there a different kind of frames used with servos/servo motors?
Servo-step sounds like the resolution of a 0 to 180 degree servo.
And if do vou have a different kind of mounting frame then print a mechanical adapter.
Yes, the suggestion by @paulpaulson would be great. You can design and 3d print a mount for the face because I don't think servo motors comes with square face like in stepper motors (most servo motors that I have seen has circular face). In some circle faced servo there will be threads for screws, so you can design a face if required or use it directly where you want to mount the motor. As you asked, the basic difference between stepper and servo motor is that, servo motors have a feedback signal to ensure positional accuracy. Few servo motors can only spin upto 90° or 180° and continuous servo motors spin 360°.
Yes.
The problem is that when people refer to servos or servomotors on this and other Arduino forum they mean servos that were initially designed for Radio Control systems like these: Servo (radio control) - Wikipedia
However in the wider world a servo motor simply refers to a motor that is designed for feedback control and has some built-in method to provide that feedback. e.g., a rotary encoder, potentiometer or resolver generally.
Those latter types of motors are also available in standard NEMA sizes. e.g., Brushless DC Motors by Pittman Motors
Does that help?
The application is to move a object through a rail, right now I'm using stepper motors for that, but since I need more speed, I'm looking for other options.
The structure is already made so that's why I was looking for something similar to NEMA 17 motors.
The stepper motors are attached to a belt that moves an item through the rail.
For what you told me, I think what I'm looking for is continuous servo motors, they look like a regular NEMA 17 motor.
Yes it does. I didin't know how to filter out the Servo(radio control) motors from my searchs.
Is there a particular keyword I have to use to look for these kind of motors?
Not that I can think of. I've heard them referred to as servos or servo motors pretty much interchangeably as long as I can remember. It's more a matter of audience: people you're talking to generally know what you mean.
How fast do you have to run your motor and what is limiting doing it with a stepper motor? What stepper, driver and controller are you using?
There are two kinds of servos that can substitute directly for steppers. One is a stepper plus an integrated encoder using a controller that can use feedback from the encoder to make sure the stepper is doing the right thing, a/k/a stepper-servo or closed loop stepper. The other is a DC or AC motor with an integrated encoder and some control electronics. However they are still driven with step/direction pulses so they are compatible with standard CNC controllers (for example). These motors are generally in NEMA sized frames for compatibility.
Then there are various DC and AC motors that often come in NEMA sized frames and may have gearboxes available that are also compatible. These are the kind of motors that may often be used with a separate sensor or encoder to make a servo system.
A good supplier of all these in my experience is:
This link takes you to a NEMA23 DC servo with integrated driver needing step and direction drive signals (just like a stepper) and with a maximum speed of 3000rpm. But is you explore the site they have a wide product range. I'm not sure if they have a product like this in NEMA17 if that's what you need.
However I wonder what is limiting the speed of your stepper and whether it could be increased?
The "RC Hobbyist Servo Motors" are hardly ever in NEMA sizes (There's a whole set of standard sizes, usually tagged by weight!), so including a "required" "NEMA" in your search will probably eliminate them.
OTOH, some "NEMA Servo motors" seem to be stepper-based (with position feedback), and some "Servo motors" are simply high-quality DC motors that you COULD attach position feedback to (ie shafts coming out both ends.)
Probably best to find an actual Motor Vendor that provides such things.
Googling "NEMA 17" "DC Servo motor" turns up this, for instance...
NEMA is used for everythng! The radio in your automobile has a NEMA size so ANY radio with that NEMA size will fit the opening and mounting positions.
Thanks for widening the views! I've not faced the term in other then stepper environments.
Is not like stepper motors is not a fast enough for the system, but since I'm doing R & D I'm exploring all the options available.
Hard to tell whether is going to make a difference or not. I have 0 experience using servomotors but they seem to be use more than stepper motors in a lot of projects.
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.
#/media/File:Micro_servo.jpg){kind=link}