Core Electronics Stepper motor maximum pulses per second

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Core Electronics sell a 400 step/rev stepper motor (SKU:ROB-10846) We want to use it in DIY telescope mount for astrophotography. One to drive the RA shaft and one to drive the Declination shaft. Tracking stars requires extremely slow movement, however the GOTO function of the mount requires short periods of increased amps power supply (which is not a problem with our controllers and drivers) to run the motors at high speed.
Can testing be done on this stepper motor to measure the upper limit of pluses per second that the motor can run at?
2022-07-05T14:00:00Z

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Hi John,

I was able to get a 200step/rev stepper to about 20RPS, so that’s about 2,000 steps/s, or 32,000 pulses/s with the micro stepping settings I had set on the stepper driver.

It mainly depends on the supply voltage.
What driver, microstep settings, and supply voltage are you using?
-James

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Welcome John, :slight_smile:

It’s also worth noting that at high pulse counts you might skip steps if there is a high load (inertia counts for a lot, especially if you have a long lever) on your motor.

How many steps per second was the GOTO function?
(if you can configure the speed that would be ideal - otherwise I imagine you’ll have to run the homing routine often)

Liam

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Thanks James,
Very encouraging information. I assume you were still reasonable happy with the performance of the motor at that high speed?? Can you recall the volts and amps that were supplied to the motor to achieve that performance?

John

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Thank Liam,

The reality with the motor and gearing is that it must be ideal for the very slow movement to track the stars and I will have to accept how ever long it takes to slew the scope across the sky to GOTO the next nebulae of interest. At 14,000 pulses per second the scope will rotate only half a degree per second.i.e.
If the next location of interest in the sky is 150 degrees away, at 14,000 pulses per second, the motor will take 5 minutes to reach the next desired location. At 32,000 pulses/s it would take half as long.
John

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Hi John,

The stepper driver was supplied with 24V (generally the limit for most drivers) and drew about 300mA, with a motor current limit of 1.5A/coil

-James

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Thanks Jesse,

Your response gives me all I need.

Thanks you very much.

John