What do I need to know to calculate the RPM of a stepper motor? I know the type of motor, number of pulses, voltage - and that's about it. Thanks - Dave
As far as I know steppers move a certain step size (sometimes 1.8 degrees) and you must input pulses at a given frequency, so you should be able to get the rpm from that
Steppers are designed to receive voltage pulses from a controller; think of a rotor with 200 poles. The same analysis rules for AC/DC motors don't apply. Pulses will make the rotor increment 1 rotational step. Generally motors are designed with 1.8 degree of rotation steps (200 steps/rev). Pulse streams are fed to the motor in a acceleration ramp-up / steady velocity / deceleration ramp-down profile. RPM is determined by the controller capability and pulses/revolution resolution, can be 1000's RPM.
Alternatively, modern stepper controllers can be "microstepping" controllers. These divide each default step into fractional steps. This makes the effective resolution 10,000's of pulses/revolution.
To add a corollary to Mike's comment, call the CONTROLLER manufacturer.
TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
With simple homebrewable driver circuits run by microcontrollers, and common size 23 stepping motors, you won't get much above 2000 full steps/second, or 10 revolutions/second, or 600 rpm. Steppers don't do thousands of RPM.
Please also note they don't ever really rotate continuously. When the state of the voltage pattern applied to the coils changes, the stepper moves, usually within a millisecond, and then stops, or if friction or inertia is too large, it moves a little, stalls, and falls back to where it was.
