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Maximum RPM for 1.8 degree stepper motor
How to get a Maximum speed for 1.8 degree stepper motor which it can go up? what is the calculation for it?

How to get a Maximum speed for 1.8 degree stepper motor which it can go up? what is the calculation for it?

By Aquilino Rodriguez on 11 February, 2002 - 9:49 am

Normally, you will have this data from the manufacturer. If not, you can get it empirically, increasing frequency until you see the motor doing "strange things". Take into account what do you want to move (transmission system, weight, accelerations, braking distances, etc...)

Best regards

Aquilino Rodriguez

(Festo Spain)

By Robert Scott on 11 February, 2002 - 10:59 am

The maximum speed depends on many things - the load (both frictional and inertial), the attempted acceleration, the power supply, and the
means of control. Some of these things may be out of your control due to the requirements of your application. Here are some things you
can change.

1. Use full stepping instead of half stepping. It is not quite as smooth, but it has a small torque advantage.

2. Use current-limited chopping control instead of passive resistive power drive. The resistive drive may be OK if the supply voltage is
extremely high, but then you would be burning up most of your power in the resistors. Switcher-regulated current control applies full power
supply voltage until the current rises to the specified level, then it begins chopping to keep the motor from burning up. Use as high a
power supply voltage as you can, consistent with the capabilites of the power driver circuit.

3. Use bipolar instead of unipolar wiring, if you have a choice. Bipolar full stepping uses all the windings all the time.

Are you asking how fast it can run, or how fast it can accelerate?

I think this varies from motor to motor,and should be available in the manufacturers literature.

I know the calculation for DC PM brushless but have been out of the stepper field for years. An accurate formula includes many variables (available bus voltage, inductance, dI/dt and peak current which depends on accel and load, Back EMF etc.). Most stepper manufacturers publish torque/speed curves for specified bus voltage. Use this with safety factors for torque margin especially if running open-loop. The torque at your max speed point with knowledge of your load determines the max accel. Be cognizant of the fact that fundamental resonance frequency (step speed) and so-called mid-range resonance are special issues with open-loop control. Some manufacturers show these regions on the curve for an "un-loaded" motor.

We are a leading stepper motor manufacturer in China. According to my expierence, for NEMA34 size motor, the max. speed in ideal condition
is about 150-200rpm, and about 1500rpm in bad condition.

If need more help, please contact us.

Mr. Rogers

GBM Motors Group (China)