Determining the motor power (rule of thumb)
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The max. speed and torque are required for the stepper motor selection and, ideally, the flow characteristics that are however only rarely available.
In stepper motors the mechanical output is not normally given in W. In many cases, however, it makes complete sense in order to make an initial estimation of which series is possible.
Calculation example:
Torque 10 Nm at 200 rpm
P = Md (Nm) * n (rpm) * π / 30
or, somewhat roughly and greatly simplified, P = Md * n * 0.1 (P [W], M [Nm], f [revs/s] = 209 W (M [Nm], n [rpm])= 10 * 200 * 0.1 = 200 W (here only one motor of the ST8918 series can be used)
The approximate formula can be used to read the power practically directly from the characteristics without making any great errors.
The power of the stepper motor increases up to a breakpoint speed and then remains relatively constant at higher speeds because the torque falls roughly in line with increasing speed.
