[tkms002]

AT has several 570 oz/in steppers. There are some that are rated at 3.5 amps


and they have some that are rated at 5 amps
here

How can motors with the same torque have different current ratings and what does that tell me?
Thanks

[ger21]

Look at the inductance, and also the torque curves.

The higher current motors will have much lower inductance,which means they have more torque at higher rpm, for a given voltage.

[automationtechinc]

AT has several 570 oz/in steppers. There are some that are rated at 3.5 amps


and they have some that are rated at 5 amps
here

How can motors with the same torque have different current ratings and what does that tell me?
Thanks

Pls check specification here. They are different body size and specification:


https://www.automationtechnologiesin...lat-381-oz-in/

https://www.automationtechnologiesin...lat-570-oz-in/

[tkms002]

Pls check specification here. They are different body size and specification:


https://www.automationtechnologiesin...lat-381-oz-in/

https://www.automationtechnologiesin...lat-570-oz-in/

you have 570 in/oz steppers rated at 5 amps and 570 in/oz steppers rated at 3.5 amps.
I see the 3.5 amp steppers have a much higher inductance but I am not an electronics guy so I really don't know what that means in practical usage.

[skrubol]

Higher inductance in a stepper means the torque falls off faster at high RPM's (with the same voltage.) So basically, with the same voltage the 5A stepper will be able to run faster than the 3.5A one.

[tkms002]

Higher inductance in a stepper means the torque falls off faster at high RPM's (with the same voltage.) So basically, with the same voltage the 5A stepper will be able to run faster than the 3.5A one.

So all other things being equal lower inductance is always better?

[skrubol]

So all other things being equal lower inductance is always better?

That might be oversimplifying, (quality isn't just determined by power,) but I think you could say will all else equal, lower inductance will mean more torque at higher RPM's..