# Nema 23, 400 RPM

Hello,
I have this step motor:
https://www.pololu.com/product/1477
and this driver:
https://www.pololu.com/product/2133

It is possible to have 400RPM speed (without load) ? or I need another driver? or motor?

Hello.

You would probably be able to achieve that speed with that stepper motor and driver at no load; however, with any significant load on it, I highly doubt you will be able to get close to that speed. You can get an idea of the maximum speed your stepper motor will be able to achieve with different loads from the pull out torque curve in the stepper motor’s datasheet.

- Jeremy

You would have to push the boundary of the voltage limit of the board, for sure. And wire in unipolar mode for less inductance. shoot for 40V. I’ve run the drivers in suitable conditions at 42V for a long time, but it’s obviously way closer to the 45V limit than you should be.

1,333 steps/s is another way to count your 400RPM result. It’s a somewhat high voltage for a stepper, and the stepper you linked is a rather high inductance stepper.

I’ve read that you want to drive a stepper at 32sqrt(inductance in mH). which in this case would be 32sqrt(14) = 120V. Obviously that formula is pretty mediocre insofar as it always depends on your application.Why would you need such a headway for a low RPM application (you wouldn’t.) but i read it in a datasheet or application note somewhere and it stuck, and seems to apply for applications when I want to shoot above 2000steps/s

The power supply on driver is 45V and the motor works on full step mode, when the signal is more than 700 Hz, the motor starting to sticking.
The speed on this frequency is 220 RPM.
I tried to change the step to 1/8 and 1/16 but nothing changed on speed.

I’m not too surprised it doesn’t work past 220 RPM. I’m afraid that that’s pushing it too fast at this winding [previous posts esp by me were too optimistic.]

If you really need that torque and speed, you’ll need a driver that can pull higher voltage or a driver with higher current, in addition to (in the latter case) a stepper wound for a lower inductance/lower rated voltage.