Motor Noises

[th3t1ck]

I have been reading different posts on this forum about motor noise because I was wondering if the noises I hear from my machine are normal. At rest some motors (or maybe all, I haven't isolated the noises) seem to make a strange noise. It reminds me of snow on a television. I have a video on youtube you can listen to at...
http://www.youtube.com/watch?v=nb_YKBFDA1k&feature=related]Start Of Dragon Head Pen Holder - YouTube

Is this normal?

[th3t1ck]

Yes they are firmly bolted down.

[mike_Kilroy]

I have been reading different posts on this forum about motor noise because I was wondering if the noises I hear from my machine are normal. ....
Is this normal?

I've heard a lot of machines. Your noise IMHO are more than normal. BUT that said, they may be normal for YOUR DRIVES.

You can pay $ 1200 for a drive like our Kollmorgen's AKD that have servo update times in Mhz (< 1.0 usec) and have low pass filters, bandpass filters, polar placement velocity loop compensation, dual Kalaman (sp?) filters, biquad filters, 3khz current loops, 800khz velocity loops, with autotuning & built ijn Bode plotting of freq & resonances of your load, that can make that type of noise go totally away without harming servo response or stiffness.

Or you can pay $ 200 for a servo drive without these capabilities and they will likely make this kind of noise.

I can tell you if MY Kollmorgen motors and drives made this noise, and i sold them to u, they WOULD be be quieted down from what you show in your u-tube video.

So, want more ideas? Tell us what details on mfgr, part nos, etc., on YOUR motors, drive, and control are so we can make better judgement calls on your noise.

[th3t1ck]

Thank you for the reply Mike. I isolated the worst of the noise coming from the Y axis. I unmounted the motor and ran it. It was nice and quiet. When I mount it on the CNC machine I hear the ugly sound again. Seems to resonate through the machine. Guess I'll have to check for loose parts.
As for my equipment, I have the following...

1. Motors - 57bygh405a
2. Controller - Toshiba 6560 5 Axis
3. Software - Mach3
4. OS - Windows XP 32 bit

[mike_Kilroy]

ah.... I just looked: those are not servos! from what I can see, that is a stepper motor driver with full to 1/16 steps.... so each of those steps can set up shakes in your machine if something can resonant or is loose, yes.

My post was off base then as I thought you said servo motors, not steppers.

For smoothest performance you should use the microstepping if you can - is it set to the highest 1/16th step? if not, probably worth trying.