Stepper motor making noise at low rpms

[RG]

I have a Nema 23 Stepper Motor than I am running as slow as 1hz @ 800
microsteps. I am getting a lot of audible electrical noise from the
motor. What can I do to reduce or eliminate this noise?

 

[Robert Baer]

I have a Nema 23 Stepper Motor than I am running as slow as 1hz @ 800
microsteps. I am getting a lot of audible electrical noise from the
motor. What can I do to reduce or eliminate this noise?

Audible, maybe but electrical, i think not.
Slow down the risetime of each step, so the motor makes a smooth(er)
transition from one position to the next.

 

[John Popelish]

I have a Nema 23 Stepper Motor than I am running as slow as 1hz @ 800
microsteps. I am getting a lot of audible electrical noise from the
motor. What can I do to reduce or eliminate this noise?

I am guessing that the pulses the drive is producing to
regulate the current are not uniform in duty cycle, and you
are hearing the low frequency dither as the controller
struggles to find the correct average pulse duty cycle. I
have had to design this effect out of a growling stepper
motor drive combination that should have had a high enough
pulse frequency to be silent.

 

[RG]

   Audible, maybe but electrical, i think not.
   Slow down the risetime of each step, so the motor makes a smooth(er)
transition from one position to the next.

Robert,
The noise is almost musical - funny.
I am sending a square wave using the PWM out function from a Parallax
SX chip.
How does one slow down the rise time independent of the frequency?

John, the duty cycle is 50% as with my square wave signal.

 

[Jamie]

Robert,
The noise is almost musical - funny.
I am sending a square wave using the PWM out function from a Parallax
SX chip.
How does one slow down the rise time independent of the frequency?

John, the duty cycle is 50% as with my square wave signal.

so I assume your tailoring the carry frequency and keeping the
duty at 50% ?

 

[John Popelish]

John, the duty cycle is 50% as with my square wave signal.

How are you micro stepping by applying a 50% duty cycle
square wave to your motor?

 

[Robert Baer]

Robert,
The noise is almost musical - funny.
I am sending a square wave using the PWM out function from a Parallax
SX chip.
How does one slow down the rise time independent of the frequency?

John, the duty cycle is 50% as with my square wave signal.

Some kind of filter..LC network might do the trick.

 

[Paul Burke]

The noise is almost musical - funny.
I am sending a square wave using the PWM out function from a Parallax
SX chip.

I used to be able to play Amazing Grace on a stepper motor drive test
rig, sounded just like little bagpipes.

 

[RG]

How are you micro stepping by applying a 50% duty cycle
square wave to yourmotor?

John, I am using a driver to 1/8th step my square wave.
I have 1600 pulses per revolution.

 

[John Popelish]

John, I am using a driver to 1/8th step my square wave.
I have 1600 pulses per revolution.

So you are not hitting the motor with a square wave, but
stepping the driver with it?

The sub cycle oscillations I mentioned have little to do
with the step rate and have everything to do with how the
driver regulates the individual step current level.

 

[Michael A. Terrell]

I used to be able to play Amazing Grace on a stepper motor drive test
rig, sounded just like little bagpipes.

Are you bragging, ot complaining? ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida