First cut from my 8520...what is this god awful noise coming from...

zakruvalcaba

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My 8520 came home this weekend. Couldn't be more excited. There's some minor work to do on it still but it's in great shape. Just started my first cut and I'm getting this terrible noise. It's so loud...to the point where I may need hearing protection. I'm using a 1/4" HSS endmill cutting about 1/8" down onto aluminum. Speed is at 1900 RPM. It seems that the faster I move on the X the noise lessens but this can't be normal....

 
Are you sure the spindle is turning in the correct direction?
Have you tried slower speeds?
Are you only getting the noise when cutting (nothing near the motor pulleys rubbing against the covers)?
Mark
ps Looks like you are using a collet chuck to hold the endmill- is it firmly held in the spindle- no looseness
 
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I would first stop the rattle of the lever on the upper left hand side of the machine and then stop any others.
 
Thanks for the quick reply Mark. I have the lever in the "Forward" position and have verified that the cutter is moving clockwise.
I have not tried slower speeds yet. I was cutting aluminum just fine with no ridiculous noises like this on my Rong Fu at 2000 RPM.
As you can hear in the video, there is no noise at first and only comes when I actually touch the work piece.
 
I would first stop the rattle of the lever on the upper left hand side of the machine and then stop any others.

This noise is REALLY loud. Very unpleasant. The brake has nothing to do with this noise...but yeah I noticed it flopping around after I looked at the video a few times. Need to figure out how to tighten it.
 
ps Looks like you are using a collet chuck to hold the endmill- is it firmly held in the spindle- no looseness

I mean I'm no expert by any means but if I hold a crescent wrench at the top and attempt to tighten the chuck...it doesn't move at all.
 
A couple more videos of the mill on before touching work piece and after touching work piece. Also, check out second video...just discovered this. I would imagine that the pulley should be secured and not be able to move up and down like that? Haha.


 
The work piece and vice are not vibrating? The Quill and table locks are locked? You have a vibration and you'll just have to keep checking them all out. And, it may be a combination of several. Good luck.
 
My 8520 came home this weekend. Couldn't be more excited. There's some minor work to do on it still but it's in great shape. Just started my first cut and I'm getting this terrible noise. It's so loud...to the point where I may need hearing protection. I'm using a 1/4" HSS endmill cutting about 1/8" down onto aluminum. Speed is at 1900 RPM. It seems that the faster I move on the X the noise lessens but this can't be normal....


You see the brake handle shaking in sync with the noise? The brake ring is bouncing against the inside of the pulley. It's probably broken, like mine was. I silver brazed the ductile iron ring back together, shimmed it to fit closely around the head, bored and sleeved the worn pulley back into close tolerance, and mine only occasionally rubs now. Not the best design, though. If the ring breaks again (and it probably will) I figure I'll make a new one that fits better.
 
A couple more videos of the mill on before touching work piece and after touching work piece. Also, check out second video...just discovered this. I would imagine that the pulley should be secured and not be able to move up and down like that? Haha.



You're missing a retaining clip. Do you have the exploded diagram of the head assembly? Go to vintagemachinery and download the manual.
 
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