resonance in stepper
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Hello. Im having a strange issue: i have a nema 23 motor for my Y axis, and Im having a resonance problem at low movement speeds: between 5 to 15 mm/s, the motor makes horrible noises and vibrations. They disappear at higher speeds.
Anyone can give me a hint on what is going on? -
@tinchus said in resonance in stepper:
Hello. Im having a strange issue: i have a nema 23 motor for my Y axis, and Im having a resonance problem at low movement speeds: between 5 to 15 mm/s, the motor makes horrible noises and vibrations. They disappear at higher speeds.
Anyone can give me a hint on what is going on?Have you disconnected the stepper so you are only hearing the stepper and not parts of the Y axis mechanics?
Frederick
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@fcwilt yes, it is the stepper 200% sure
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@tinchus said in resonance in stepper:
@fcwilt yes, it is the stepper 200% sure
Well 200% sounds very sure.
I recently encountered a noise problem in a new printer I was building.
I tracked it to one of the linear rails. I tried adjusting the alignment, lubrication, etc but nothing made significant improvement.
I installed another unit I had and the noise was gone.
Perhaps just a bad stepper?
Frederick
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@tinchus I used a ball screw driven by a NEMA-23 stepper for the Y axis in a printer a few years ago. That thing had terrible resonance at about 50 mm/sec. I tried everything I could think of to get rid of it and never got it under control. I had to limit speed to 40 mm/sec to avoid the resonance- it could easily run at 80 mm/sec or more, but when it hit a curve that would cause the speed in the Y axis to drop into the 50 mm/sec range, it would make terrible noise.
I eventually replaced it the ball screw with a belt and there were no more problems, other than the normal greater vibration that NEMA-23 motors produce compared to NEMA-17 motors.
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@tinchus, steppers have natural resonant speeds that vibrate and might even stall from the vibration. This is especially evident at full and half steps.
what microstepping have you set? Increasing the number of microsteps/step will reduce this.
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@tenaja in my config the steppings are in a value of 16 and interpolation activated.
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damper mount for the stepper?
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@tinchus as the others have said, stepper motors (and any electromechanical system) will have a (several) natural frequencies that can cause issues, it just depends where those natural frequencies are.
Essentially your choices are to change the stiffness (change the motor currents, or maybe the stiffness of the mechanical system), change the mass (maybe add some inertia to the motor shaft), smooth out the excitations (e.g. increase your microstepping, though you're already interpolating up to x256), or to try and damp it out (damper mounts etc).Typically larger Nema23 motors are worse for this than Nema17. This is in part because they have a higher inertia, so a lower resonance frequency, but I believe there is also something fundamental about their design
