Fadal spindle belt noise??

Hey guys!
I'm in the process of rebuilding a Fadal VMC15. Running the spindle for the first time after replacing the spindle drive and having the spindle motor rebuilt I hear a very high pitch whistling kind of noise coming from the area around where the belt is running. At 7500RPM it is absolutely unbearable and you'd have to wear hearing protection to be near it for any length of time...

I tested the motor by itself all the way up to 7500RPM and it is practically silent, buttery smooth. To test whether it was the spindle itself I threw in a spare spindle that I had on hand, and would you believe the noise is still there??

Next I tried varying the belt tension. With very little tension the noise is practically gone, with really high tension the noise is awful... In my mind that leaves 2 possibilities:

1) The motor shop didn't replace the bottom bearings of the motor (they say they did though).
2) The belt itself is making this noise?

The belt/pulleys are gates timing belt style with big teeth. I can see how the belt pushing the air out from in between the teeth could be quite noisy, but are they actually this loud??

Bear in mind I am running this machine without the head covers on, just for testing. I have heard another VMC15 make similar sounds without the head guarding installed but I thought that machine might have a bad spindle.

Here is a short video of the noise: [video]https://www.instagram.com/p/B2XXf0enTmx[/video]

Here's a photo of the belt/pulley (this is the spindle pulley):


Any thoughts? Is this noise normal belt noise or is it something else? Will it be contained by the head guarding when the machine is fully back together?

My other Fadal has the older 'multi-vee' style of belt and that is definitely much quieter...

Thanks guys!
-Aaron

The 7500 rpm spindles are noisy because of the Gilmore style belt. Get that sticky back sound deadener that the stero guys use in the car doors get it at blowes line the inside of the cover does yours have the extra 2 pieces of tin to cover the top side. It splits and goes around the spindle motor if so line it also


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D Nelson said:

The 7500 rpm spindles are noisy because of the Gilmore style belt. Get that sticky back sound deadener that the stero guys use in the car doors get it at blowes line the inside of the cover does yours have the extra 2 pieces of tin to cover the top side. It splits and goes around the spindle motor if so line it also


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Yeah mine has the split top cover, the other VMC15 that I've heard which was noisy did not have that installed, and I'm definitely wondering if that's why it was noisy... Thanks for the feedback mate! I will have to look up Gilmore style belts as I haven't heard of those before. I will look into the sound deadening sheets as well, good idea!

those cog style belts trap air and get pretty darn noisy if you tighten them to tight. the Haas are the same way. I find I adjust them til the belt running from the spindle to the motor looking down on the edge isnt straight, but has a slight curve to them. they seem to work great and aren't to noisy.

Get a new belt my vmc was at 95db I thought it was spindle bearings got a new belt 70db No mater how good the belt looks
replace it wit a new one.

aarongough said:

Yeah mine has the split top cover, the other VMC15 that I've heard which was noisy did not have that installed, and I'm definitely wondering if that's why it was noisy... Thanks for the feedback mate! I will have to look up Gilmore style belts as I haven't heard of those before. I will look into the sound deadening sheets as well, good idea!

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The cogged style belt on the 7500 rpm spindles like what are on a supercharger is what we always called Gilmore style. The 10k spindles use a serpentine style belts 2 of them instead of 1 the grooves go around the belt instead of crossways. But the 7500 rpms are always noisier then the 10k


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I have experience with 2 Fadals with the 15k spindle,which also use this type of belt,
and they were all extremely noisy,even brand new.

In 2002 the head covers did not come with the noise damping material yet.The Fadal techs added the foam after we complained.That helped a little bit.


I built an aluminum enclosure out of 1/2 aluminum plate that mounts to the subplate that holds the motor and sits on the head casting.
There are only a couple square inches of vents for some airflow.

It is quite a bit better but still noisy.
I also get belt vibrations at some rpms above 7000,depending on how tight the belt is.

Kallam said:

Get a new belt my vmc was at 95db I thought it was spindle bearings got a new belt 70db No mater how good the belt looks
replace it wit a new one.

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Unfortunately this is with a brand new belt already, and a high quality one too... Gates CarbonGT belt. I tried the old one to see if it was quieter but they're both about the same...

Highfeed said:

I have experience with 2 Fadals with the 15k spindle,which also use this type of belt,
and they were all extremely noisy,even brand new.

In 2002 the head covers did not come with the noise damping material yet.The Fadal techs added the foam after we complained.That helped a little bit.


I built an aluminum enclosure out of 1/2 aluminum plate that mounts to the subplate that holds the motor and sits on the head casting.
There are only a couple square inches of vents for some airflow.

It is quite a bit better but still noisy.
I also get belt vibrations at some rpms above 7000,depending on how tight the belt is.

Click to expand...

Damn! Maybe I'll have to look at converting this to the 'muti-vee' style of belt as that is waaaay quieter and I've never had issues with one slipping. None of my machines have rigid tap anyway so that shouldn't be an issue.

I have heard of supercharger guys drilling small holes in the Vee between the teeth to quieten the belt whine.
Apparenty gives the air somewhere else to go.

Thanks for the feedback guys! I was able to find a pair of the older-style 'pozidrive' pulleys on eBay that will fit this machine. I have that style of pulleys on one of my other machines and the drive belt itself is basically silent. I will likely shell out the couple of hundred dollars to make the change over, I think the quality of life improvement is worth it given that I often run at the max RPMs on these machines (7500rpm) and at that speed the spindle is very noisy!

I will report back once everything is installed! I expect it should be fairly straight forward, just heat the old pulleys off and shrink the new ones on!

I think part of it is that you're so spoiled in your neat, clean, quiet, organized shop, you're not used to machines making noise

You mean making money


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TeachMePlease said:

I think part of it is that you're so spoiled in your neat, clean, quiet, organized shop, you're not used to machines making noise

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Yeah guilty as charged most likely I've actually been trying to quiet the shop down even more, part of the reason I was unimpressed by the noise level of this machine! Bought a second hand screw compressor a little while ago that I'm looking forward to getting setup!

D Nelson said:

You mean making money

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I insist my machines make money I just also insist they're quiet while doing it!

There is a sticker requiring hearing protection after all....
it's air noise. It's obnoxious. I think I'll try to run mine looser as suggested and see what changes. Mine does not have foam so I may try that also.

As a follow up to this thread:

I looked everywhere for the older style 'pozidrive' pulleys for this machine. Turns out Fadal only used those pulleys for a very brief period of time and my VMC10 is a very rare bird indeed to have them! None of the Fadal parts suppliers have them in stock. One place said they might be able to get them, but lead time would be 6-8 weeks and cost would be $500 per pulley!!

I decided to follow one of the suggestions posted previously instead, using automotive sound-deadening sheets inside the head enclosure to quiet things down. This ended up being quite simple and cheap to do. The butyl sheets were $45 for 25 sq ft of 80 mil sheet, and they went on fairly easily. The difference between the un-insulated panels and the insulated panels (in terms of resonance) is crazy, really impressed by that: Aaron Gough on Instagram: “Adding sound insulation to the inside of the head enclosure for Vicky, using 80 mil butyl sheet that is normally used to sound deaden car…”

Results:
Without the head enclosure on: 93db @ 6 feet
With the insulated head enclosure: 81db @ 6 feet

Overall the sound is much more reasonable. It's still a bit higher pitched than I'd like, and my VMC10 is *still* quieter at only 78db @ 6 feet even without a sealed head enclosure!!

Video: Aaron Gough on Instagram: “12db noise reduction! Yes!! It was about 93db from this distance with the enclosure off. With the new sound insulating enclosure it's only…”

Thanks for all the suggestions guys!
-Aaron

I like that noise meter, whered you get it?

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Cole2534 said:

I like that noise meter, whered you get it?

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Just off Amazon, 'Tacklife' brand. I think it was like $25. Probably not the greatest quality, but it has worked well for me for a couple of years now.

Mine was being very noisy and not tracking well even when perfectly setup. What I ended up doing was setting the tension relatively light and then using a soap bar to put a little dry soap on the belt teeth. That made the belt track and in my opinion quieter. I don’t have any sound meter though.

Also talk to fadal cnc they sell a non gates belt that is a different brand I forget the brand at the moment but I heard that it can help it run more quietly.

I believe it’s a German brand belt might start with an O I’m drawing a blank at the moment.