Buzzing noise after VFD conversion

[7milesup]

interestingly , I notice on the sound tone video their is also nothing above 16khz so I think it's youtube doing a low pass filter.

View attachment 411854

Stu

edit , you can generate tones with audacity too.

I didn't realize that those graphs were of MY videos. Very interesting.

 

[Jeff.64]

interestingly , I notice on the sound tone video their is also nothing above 16khz so I think it's youtube doing a low pass filter.

View attachment 411854

Stu

edit , you can generate tones with audacity too.

Thanks for the link. Several years ago, I downloaded some similar Youtube files and determined that my hearing sensitivity stopped at 14 kHz. So maybe my hearing range was limited by YouTube... interesting. I posted the link to be used as a quick and dirty method to determine if the fundamental frequency of the motor was 16 kHz. That is, you could compare the tone of the motor to the YouTube videos. I wonder if an external microphone with a flat enough response is available for use with a cellphone, and if so, is a cellphone DSP good enough to supply a spectrum analyzer app to see what the fundamental motor frequency and harmonic amplitudes are. I've seen people use the accelerometer chip in their cellphones with an app to make some vibration plots in x, y and z. Might be a gimmick that could only tell you which axis has the greatest amplitude. Granted it's no IRD. Often thought about rolling my own as even used ones (Radwell) were out of my price range for hobby use. Maybe there are some antique IRD's on Ebay by now... Just checked. I think I'll wait a little longer. Yeah, I know, a little long winded.

 

[stupoty]

Thanks for the link. Several years ago, I downloaded some similar Youtube files and determined that my hearing sensitivity stopped at 14 kHz. So maybe my hearing range was limited by YouTube... interesting. I posted the link to be used as a quick and dirty method to determine if the fundamental frequency of the motor was 16 kHz. That is, you could compare the tone of the motor to the YouTube videos. I wonder if an external microphone with a flat enough response is available for use with a cellphone, and if so, is a cellphone DSP good enough to supply a spectrum analyzer app to see what the fundamental motor frequency and harmonic amplitudes are. I've seen people use the accelerometer chip in their cellphones with an app to make some vibration plots in x, y and z. Might be a gimmick that could only tell you which axis has the greatest amplitude. Granted it's no IRD. Often thought about rolling my own as even used ones (Radwell) were out of my price range for hobby use. Maybe there are some antique IRD's on Ebay by now... Just checked. I think I'll wait a little longer. Yeah, I know, a little long winded.

View attachment 16khz.mp3

One 16khz test tone, ear safety first , don't have your sound tooo high, turn the volume up whilst it's playing or look out for young'uns clutching there ears in pain


I've had quite good success with phone based spectrum analysers for basic investigation of frequency there are a few free to download in the play store / app store. I just checked the one on my phone , it clearly "sees" (hears) the 16khz tone.

Stu

 

[mksj]

You will find that many lathes and mills use the Yaskawa drives, including the factory Sharp mills. There are various models, typically the V1000 is used, but it has been updated to the GA500 and GA700 models. Both models have worked very well. Alternative is the Hitachi WJ200-022SF or the Teco E510. In this case it is hard to tell what the issue is, but so far when I encounter tuning/motor issues like this it is typically the VFD is a poor match for the motor. It may also be that the VFD circuitry may not supporting the higher switching frequency, I read elsewhere that going from 8khz to a 16khz requires almost double the cost in components. Putting on bad-aids to try to fix a poor VFD is not a good solution. The mill motor is not that old and should not have the issues seen with older mill motors. I use the Yaskawa VFD's in both my lathe and mill, carrier frequency is 12kHz and I do not hear it at 60 Hz.

GA50UB012ABA - 3 HP, 12 Amps, Normal Duty, 3 HP, 11 Amps, 240 VAC, Heavy Duty, Single-Phase, IP20/Protected Chassis

GA50UB012ABA - 3 HP, 12 Amps, Normal Duty, 3 HP, 11 Amps, 240 VAC, Heavy Duty, Single-Phase, IP20/Protected Chassis

Yaskawa - GA500 AC Microdrive - GA50UB001ABA - 1/16 HP, 1.2 Amps, Normal Duty, .17 HP, 0.8 Amps, 240 VAC, Single-Phase, IP20/Protected Chassis

control-concepts.myshopify.com

Hitachi WJ200-022SF

VFD, 3hp, 200V, Single Phase, Sensorless Vector, I

VFD, 3hp, 200V, Single Phase, Sensorless Vector, IP20, High Starting Torque

www.wolfautomation.com

Teco Westinghouse E510-203-H-U

E510-203-H-U

E510-203-H-U quick delivery, authorized Teco Westinghouse distributor. Offers complete line of AC Drives . Easy online ordering, rewards program, and great pricing.

www.wolfautomation.com

 

[7milesup]

I replaced the Lapond VFD with a WEG from Automation Direct. WEG CFW300 VFD
I did a quick basic wiring job on the WEG and got the mill running (no remotes programmed in yet). At first, I thought it sound just as bad or worse than the Lapond but then realized that the default carrier frequency is 5kHz. I increased it to 15kHz and the buzzing seems to have gone away and is running rather smooth. Need to do some fine-tuning yet but I think this VFD is a keeper.

Now I have to figure out why there is some drivetrain noise. My inclination is that it might be coming from the power drawbar shaft, but need to examine it further.

 

[wachuko]

Man, I don't trust your hearing... get your daughter to confirm!

Joking, joking...

Glad that got resolved! Once my VFD was running the motor quietly, it became clear that the bearings in the pulley were shot... lol...

 

[Jeff.64]

Glad to hear the drive was the culprit as opposed to the motor. I think a different motor would look ugly in place of that good looking OEM motor currently on your mill.
From what I can see in your videos, the motor looks like it was custom made for the mill.
Have a happy and safe 4th.

 

[7milesup]

I was just out there Jeff messing around with it and I thought "this mill sure runs smooth and quiet!"

Now I need to figure out this ancient and archaic CNC portion of it.