[bl775]

After just getting our OmioCNC X8 everything was working great. The spindle would not make any noise as long as the speed stayed below 12500 rpm. However, as soon as we turned the rpm up to 13000, it began to make a much louder noise, that seemed as if it was being strained. The sound could best be described as "REEEEEEE". The spindle is supposed to be able to run at 24000 rpm, so shouldn't 13000 rpm not be a problem? Are there any suggestions of what to do or any idea of what might be happening?

[Mmpie]

If it's a "REEEEEEE" in C major, its normal. If it's a more of a B flat minor 7th "REEEEEEE" there might be a problem.

Hope this helps.


Sent from my iPhone using Tapatalk

[mactec54]

After just getting our OmioCNC X8 everything was working great. The spindle would not make any noise as long as the speed stayed below 12500 rpm. However, as soon as we turned the rpm up to 13000, it began to make a much louder noise, that seemed as if it was being strained. The sound could best be described as "REEEEEEE". The spindle is supposed to be able to run at 24000 rpm, so shouldn't 13000 rpm not be a problem? Are there any suggestions of what to do or any idea of what might be happening?

Could be a bad spindle, what is the slowest you have run it, is it air cooled or water cooled, and what size is it, post a video of the spindle running

[bl775]

If it's a "REEEEEEE" in C major, its normal. If it's a more of a B flat minor 7th "REEEEEEE" there might be a problem.

Hope this helps.


Sent from my iPhone using Tapatalk

Ah geez! It's B flat minor.

[bl775]

Well I will be back at the shop next Saturday , so I will make sure to take a video then.

[bl775]

Back in the shop! Took a video of the spindle ramping up to 13k rpm. 2 issues arose:

1. Spindle speed is not correlated with VFD readings. While the mach3 setting was at 13,000 rpm, the VFD exceeded the frequency (217) by around 60 Hz to ~283 Hz, which would result in around 16000 rpm. This doesn't fully explain the sound, but it might be a factor. Unfortunately, we do not have a tachometer and are pretty much relying on the VFD measurement in regards to spindle speed.

2. Obviously, the noise. This starts at around 283 rpm and is VERY loud. Sounds like it's in C major, but I'm fairly certain this sound isn't normal. It can also be heard in the second attached video where the mach3 setting was at 8000 rpm. I've double checked the VFD settings and am fairly certain this shouldn't be the issue. Could it be acceleration? The VFD (I know some of these are prone to come damaged)? Bearings?

Any help would be great.

Video 1 (13k rpm)
https://www.youtube.com/watch?v=bUzzLeXmGp8
Video 2 (8k rpm)
https://www.youtube.com/watch?v=eCk3mWmDKsg

[extent]

calibration on your 10v spindle output for the vfd is off. trust what the vfd says it's doing. You can probably adjust some vfd parameters to compensate for the values it reads, but it may be easier to just have a quick chart for what actual rpm you get for the rpm you set in mach and compensate for it manually.

the noise in your videos sounds like not the spindle at all. sounds like you're hitting harmonic points on the gantry and it's body work that's making all the noise. I would bet on that x axis cover vibrating. run your spindle up a gain and press down on that cover and I'll bet it will go away.

[mactec54]

Back in the shop! Took a video of the spindle ramping up to 13k rpm. 2 issues arose:

1. Spindle speed is not correlated with VFD readings. While the mach3 setting was at 13,000 rpm, the VFD exceeded the frequency (217) by around 60 Hz to ~283 Hz, which would result in around 16000 rpm. This doesn't fully explain the sound, but it might be a factor. Unfortunately, we do not have a tachometer and are pretty much relying on the VFD measurement in regards to spindle speed.

2. Obviously, the noise. This starts at around 283 rpm and is VERY loud. Sounds like it's in C major, but I'm fairly certain this sound isn't normal. It can also be heard in the second attached video where the mach3 setting was at 8000 rpm. I've double checked the VFD settings and am fairly certain this shouldn't be the issue. Could it be acceleration? The VFD (I know some of these are prone to come damaged)? Bearings?

That is a Bearing noise, the Bearing cage is skidding which is not a good sign, when you said the noise started at around 283 RPM, If you have your spindle running at those low RPM it will over heat, and the grease in the bearings will run out, hence the noise you hear is from the Bearing having very little lube left in them

The minimum RPM for these spindles is 6,000 RPM, so in your VFD the minimum RPM Parameter Setting would be set at 100, so let hope you have not been running the spindle below the minimum RPM

For the RPM problem that takes a bit of playing with in Mach 3 mostly, that is not an unusual problem and is no real concern, and has nothing to do with your spindle noise

[bl775]

That is a Bearing noise, the Bearing cage is skidding which is not a good sign, when you said the noise started at around 283 RPM, If you have your spindle running at those low RPM it will over heat, and the grease in the bearings will run out, hence the noise you hear is from the Bearing having very little lube left in them

The minimum RPM for these spindles is 6,000 RPM, so in your VFD the minimum RPM Parameter Setting would be set at 100, so let hope you have not been running the spindle below the minimum RPM

For the RPM problem that takes a bit of playing with in Mach 3 mostly, that is not an unusual problem and is no real concern, and has nothing to do with your spindle noise

Sorry, I misspoke, it isn't spinning at 283 rpm, rather the inverter is supplying current at 283 hertz (equal to 16,980 rpm). You could be right about the bearing lubrication, though this CNC is less than 2 weeks old and I assume they ship it lubricated.

[mactec54]

Sorry, I misspoke, it isn't spinning at 283 rpm, rather the inverter is supplying current at 283 hertz (equal to 16,980 rpm). You could be right about the bearing lubrication, though this CNC is less than 2 weeks old and I assume they ship it lubricated.

You have a Spindle with Bad Bearings then, if it has not been over heated, by incorrect VFD Parameter Settings, then speak to the Seller about a replacement Spindle

They the seller builder have no control on the Spindle Bearing Lubrication, that part is from the Bearing Manufacture as the Bearings are Sealed, they are then used and installed by the Spindle Manufacture, not the machine manufacture, they only put the parts together and sell it to you

[dharmic]

That's nasty.

Take the spindle out of the machine, hold it somehow and run it up. If it doesn't make the sound anymore then time to go back and double check the rest of the machine, if it does then the spindle is toast. It's a quick check just to ensure you're not going to be fighting for a replacement only to find out it was a loose screw on the gantry.

[bl775]

Well, we fixed the sound. It turned out to be a lose plate, and now we can comfortably run at 300hz. Thanks for the help.

[mactec54]

Well, we fixed the sound. It turned out to be a lose plate, and now we can comfortably run at 300hz. Thanks for the help.

That's good you found the problem, and the spindle is ok, you also know what the spindle will sound like when a Bearings are getting near replacment

[extent]

Would a bearing going that bad be able to be felt at all just by hand under no load?

[mactec54]

Would a bearing going that bad be able to be felt at all just by hand under no load?

Sometimes no you would not be able to feel it, by hand, this is not a loaded problem, when the Bearing is lacking Lube, or sometimes has to much lube the cage will stop spinning, and the balls are just skidding in the bearing race, most times if the Bearing lube is ok the cage will catch up with the rotor speed and the motor will run fine