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Possible damage to spindle motor or VFD - help really appreciated!
Hi all,
Well, this certainly has not been the best of days :( ... I was slowly milling into a steel bolt/a cast iron base with my 2.2 kW spindle and 2.2 kW Huanyang VFD, and I seem to have damaged either the spindle motor or the VFD unit ... During the steel bolt/cast iron milling I happened to lower the Z-axis a little bit too quickly (although not very quickly) and this slightly halted the motor for a moment - but not at all to a stop.
However, normally the VFD accelerates the motor gradually while generating a motor sound with a slowly increasing frequency, yet after this steel/cast iron milling this sound is suddenly completely changed (??) .. I have attached a short sound recording to this post where this new sound can be heard during motor accelleration and deceleration.
Also, it seems that the motor now vibrates slightly in a "thud-like" manner as if the VFD power is applied sort of in an uncoordinated manner.
In order to try to assess if the spindle motor itself has been damaged I have rotated the spindle by hand so as to maybe feel if there could be a damaged bearing but it does not appear to be the case. The spindle appears to rotate freely without any "grits" or the like during rotation. Also no grit sound.
I wonder, however, if this steel/cast iron milling somehow may:
1. Either have caused a current surge in the VFD which have damaged the VFD's output circuitry, or
2. Maybe a power drop inside the VFD which may somehow have damaged the internal settings or ?? in the VFD?
Might I be so lucky that someone here knows about what this could be, and may suggest a remedy? I use the CNC mill almost daily so it really is a setback that this has happened ... I would much appreciate help here ...
With many thanks,
Jesper
Re: Possible damage to spindle motor or VFD - help really appreciated!
It sounds like you burned up something in your spindle, which was never designed for milling steel or cast iron. These high-rpm self-contained spindles can handle wood, plastics, and aluminum, but shouldn't be used for anything heavier than engraving on harder materials. How fast was it spinning when it had the problem? Fortunately, those Chinese spindles are pretty inexpensive, so replacing it won't be too painful. I doubt you'll find anyone who can fix it for less than the replacement cost.
Re: Possible damage to spindle motor or VFD - help really appreciated!
Hi Andrew,
& thanks for your feedback! As it is I tried to power up the motor again this morning and much to my surprise after 1-2 minutes these noisy sounds disappeared again ???? ... So at least for now a little bit of "calmness" in this part of the world although I guess that likely there's a bearing or "something" that is no longer working at its best :o ... Nevertheless, it is a relief as it appears that I can continue working and I won't have to replace the motor right now (it is a bit more expensive than the typical Chinese spindle motor - as it actually is specified to be able to work with e.g. steel, has precision bearings & a high(er) torque than normal for this wattage).
Anyway, thanks again for your feedback & have a good day,
Jesper
Re: Possible damage to spindle motor or VFD - help really appreciated!
Quote:
Originally Posted by
evalon
Hi Andrew,
& thanks for your feedback! As it is I tried to power up the motor again this morning and much to my surprise after 1-2 minutes these noisy sounds disappeared again ???? ... So at least for now a little bit of "calmness" in this part of the world although I guess that likely there's a bearing or "something" that is no longer working at its best :o ... Nevertheless, it is a relief as it appears that I can continue working and I won't have to replace the motor right now (it is a bit more expensive than the typical Chinese spindle motor - as it actually is specified to be able to work with e.g. steel, has precision bearings & a high(er) torque than normal for this wattage).
Anyway, thanks again for your feedback & have a good day,
Jesper
They can work with steel but only light engraving, the Spindle Bearing Design is not suitable for milling steel, don't go by what the manufacture has posted as they would of only been referring to engraving
Correct that is partly Bearing noise along with frequency noise, I would say your Parameters may not be set correct also can you post the Parameter list what you have used for the drive you have
Re: Possible damage to spindle motor or VFD - help really appreciated!
@mactec54:
Hi ... & thank you also for your feedback :) As to your question about the settings of my VFD I actually think that I am using the settings you have suggested here:
https://www.cnczone.com/forums/spind...ml#post2071668
I have changed a couple of settings like e.g. the start up and stop intervals so that it ramps up speed and stops relatively slowly. Also, my spindle is not an air cooled version but water cooled.
I have used it on some occasions to mill e.g. cast iron (relatively slow speeds, low depth of cuts, "carefully"), and normally it goes fine - but, well, this time "something" that I don't exactly know what may be happened and caused these odd sounds. However, yesterday I decided to run it free wheeling for some hours - slowly increasing the rpm up to max - and it appears to be back to normal (real milling obviously is needed to reveal if this is actually also the case) ... So, for now, I don't exactly know what happened but I have made a decision to be more careful with the drive/spindle onwards. Fortunately normally I only mill non-ferrous metals, plastics and wood so hopefully it will be fine ...
Cheers,
Jesper
Re: Possible damage to spindle motor or VFD - help really appreciated!
Quote:
Originally Posted by
evalon
@mactec54:
Hi ... & thank you also for your feedback :) As to your question about the settings of my VFD I actually think that I am using the settings you have suggested here:
https://www.cnczone.com/forums/spind...ml#post2071668
I have changed a couple of settings like e.g. the start up and stop intervals so that it ramps up speed and stops relatively slowly. Also, my spindle is not an air cooled version but water cooled.
I have used it on some occasions to mill e.g. cast iron (relatively slow speeds, low depth of cuts, "carefully"), and normally it goes fine - but, well, this time "something" that I don't exactly know what may be happened and caused these odd sounds. However, yesterday I decided to run it free wheeling for some hours - slowly increasing the rpm up to max - and it appears to be back to normal (real milling obviously is needed to reveal if this is actually also the case) ... So, for now, I don't exactly know what happened but I have made a decision to be more careful with the drive/spindle onwards. Fortunately normally I only mill non-ferrous metals, plastics and wood so hopefully it will be fine ...
Cheers,
Jesper
There are other setting that can help with lower speed torque mid voltage and mid frequency these are not set in that parameter set which was from some years ago, all the main basic Parameters are there but there are more that can help at lower RPM
Re: Possible damage to spindle motor or VFD - help really appreciated!
@mactec54:
Quote:
There are other setting that can help with lower speed torque mid voltage and mid frequency these are not set in that parameter set which was from some years ago, all the main basic Parameters are there but there are more that can help at lower RPM
Hi .. if you have a link/a copy of the additional settings I'd be very interested in seeing them. I think the spindle (normally) works very well but if it can be further optimized that would be great! Not least at lower rpms where the torque admittedly is a little low from time to time ...
Cheers,
Jesper
Re: Possible damage to spindle motor or VFD - help really appreciated!
Quote:
Originally Posted by
evalon
@mactec54:
Hi .. if you have a link/a copy of the additional settings I'd be very interested in seeing them. I think the spindle (normally) works very well but if it can be further optimized that would be great! Not least at lower rpms where the torque admittedly is a little low from time to time ...
Cheers,
Jesper
Each setup can be slightly different I would have to have all your spindle and VFD Drive spec's and supply Voltage and then I can calculate the correct V/H numbers once you have the V/H number then you can add the other Parameter's
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Re: Possible damage to spindle motor or VFD - help really appreciated!
Hi Mactec54 ...
& thanks for (maybe ;)) being able to calculate V/H values for the VFD/spindle combination I have ...
As to the VFD I have attached a picture of the product label to this post. I think this is likely the information I have on this drive regarding the electrical parameters. In practice I would guess that the supply voltage is more like 226 VAC (only one phase) under load if that makes a difference.
Regarding the spindle motor all I know about it is shown in this ebay ad (information mainly at the bottom of the ad):
https://www.ebay.com/itm/DE-2-2KW-ER...kAAOSw1oJdFXv6
When I bought it I actually asked the seller whether it was capable of milling ferrous metals and he said yes. So I occasionally use it to mill cast iron (and very rarely steel) - and it works reasonably - but for other non-ferrous metals and wood/plastics I think it is great.
Is the above information sufficient for you to calculate V/H values (hopefully not too lengthy a process ... )?
Cheers & have a good weekend,
Jesper
