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I've got used 34HS8801 NEMA34 stepper motor which I am experimenting with. Unfortunately, dtasheet doesn't provide driving voltage, nor does it provide maximum RPMs.

Now, I would like to see how fast the motor can go. And turns out it stalls at approx 10 revs per second. It also depends on a way how I drive it. If I increasing speed slowly - stalling happens at higher speed.

Here is what I would like to understand:

  • Is it possible to know maximum speed stepper can handle before it stalls. I understand it depends on torque, but I would be OK with average value.
  • Is it possible to get working voltage range for the motor based on coil resistance and inductance? If not - how do I know the correct working voltage?
  • Stepper driver has few options for microstep setting. Other than step resolution - does ut make any difference when driving motor @ 400 Hz with 400 pls/rpm or at 4 kHz @ 4000 pls/rpm?
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  • \$\begingroup\$ The maximum DC voltage rating would just be the current rating times the phase resistance--the voltage you can apply while it's spinning, however, is more complicated. I'm not familiar with stepper motors, so I can't really help beyond that. \$\endgroup\$
    – Hearth
    Commented May 3, 2022 at 14:06

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Stepper motors are strange beasts. For example, they can hold a position, differently from other kind of motors (BLDC also can, but less precisely). And in fact often they are used to move-position-hold.

Anyway, about voltage and current: what really is important is the current: you can start using up to the nominal value, and check if the torque is enough for you, and check that the motor does not get too hot.

About the voltage, the true limit is isolation of the windings; higher the voltage and higher the possible speed - but always limiting the current! For a Nema-34 I think that 24 volts up to 40-50 are reasonable.

About stepping and microstepping, generally microstepping is better: if well implemented, it will give smooth movement and acceptable torque. Note that there are different kinds of ustepping: 1/4, 1/8...1/128 - some controllers switch dynamically between them.

Without microstepping you can gain some torque, but with the risk to incur in "resonance" and other problems.

The matter is complicated: read a lot about driving stepper motors, test and try a lot, and use good controllers.

About speed, there is a few things to say. Making a ramp is always a good idea, unless you have a very low speed and plenty of current (look for "pull-in" and "pull-out"). When the ramp finishes, the best is to provide the "right" current: too little current and the motor loses a step (once a single step is lost, the motor halts). Too much current and the motor gets noisy and may also lose steps. The "right" current varies with load and speed... Using full step, with 20-30 volts, you can expect to reach from 800 to maybe 1600 Hz (steps/s) without load. Having 200 steps/turn, this is 4-8 rev per second. But things can vary considerably. All in all, stepper motors are not good for high speeds.

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