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

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zakruvalcaba

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#1
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....

 

markba633csi

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#2
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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RandyM

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#3
I would first stop the rattle of the lever on the upper left hand side of the machine and then stop any others.
 

zakruvalcaba

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#4
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.
 

zakruvalcaba

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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.
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.
 

zakruvalcaba

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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.
 

zakruvalcaba

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#7
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.


 

RandyM

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#8
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.
 

Briney Eye

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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....

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.
 

Briney Eye

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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.
 

benmychree

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#11
Also, you have that end mill hanging way to far out of the collet; it may be better to use end mill holders that fit directly in the spindle.
 

markba633csi

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#12
Agree with John, whatever else may be wrong, that endmill/toolholding arrangement is hanging too far out
 

Briney Eye

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#13
You're missing a retaining clip. Do you have the exploded diagram of the head assembly? Go to vintagemachinery and download the manual.
I thought of something else. Have you adjusted the play in the quill? I still think it's the brake ring rattling against the inside of the pulley, but if things are loosey-goosey in the top of the head that will amplify the problem. Make sure that the pulley sleeve is tightened down to the top of the head, the bearing retaining clips are properly installed, and that the spline follower plate is tight on the top of the pulley. There are also a couple of spring-loaded "plugs" (557-007) in the plate (556-020) that grip the splined spindle shaft, keep it from rattling, and also keep the quill where you put it when they're properly adjusted. Check for play in all of the bearings, too. I was fortunate and the quill bearings in mine were still good, but I replaced all of the other bearings anyway. They're cheap, and I figured that since I already had it apart I might as well install new ones.
 

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#14
Post 7 the end mill looks crooked when zoomed in, is the collet snapped into the nut before installing onto the chuck ,
Just looks funny.
Edit are you sure it’s turning cw looks ccw when stoping. Sounds like a train whistle,May be a optical thing
 
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zakruvalcaba

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#15
Agree with John, whatever else may be wrong, that endmill/toolholding arrangement is hanging too far out
Thanks for the tip. My work piece (which is not shown in the video) requires a depth of cut of 1.500" which is why my end mill sticks out so far. There's an additional .500 of clearance required for a jig so the end mill length needs to total 2.000". Not making excuses, it's just I need the length.
 

zakruvalcaba

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#16
Post 7 the end mill looks crooked when zoomed in, is the collet snapped into the nut before installing onto the chuck ,
Just looks funny.
Edit are you sure it’s turning cw looks ccw when stoping. Sounds like a train whistle,May be a optical thing
Yes, it's snapped in and yes, I'm 100% positive that it's turning cw.
 

zakruvalcaba

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#17
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.
I'm pretty sure it's not the brake. I held it firmly with my left hand and manipulated the X with my right hand and the noise was still there.
 

zakruvalcaba

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#18
I reduced my speed from 1900 to 600 and the noise has SIGNIFICANTLY reduced....almost non-existent. At this point, I'm guessing it's the pulley rattling at higher speeds since it's not secured correctly?
 

zakruvalcaba

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#19
I thought of something else. Have you adjusted the play in the quill? I still think it's the brake ring rattling against the inside of the pulley, but if things are loosey-goosey in the top of the head that will amplify the problem. Make sure that the pulley sleeve is tightened down to the top of the head, the bearing retaining clips are properly installed, and that the spline follower plate is tight on the top of the pulley. There are also a couple of spring-loaded "plugs" (557-007) in the plate (556-020) that grip the splined spindle shaft, keep it from rattling, and also keep the quill where you put it when they're properly adjusted. Check for play in all of the bearings, too. I was fortunate and the quill bearings in mine were still good, but I replaced all of the other bearings anyway. They're cheap, and I figured that since I already had it apart I might as well install new ones.
I'll take this thing apart when I have some free time. This is the worst part of the year for me with kids being home, vacations, work, etc. but I'll get to it. Thanks for the reply. These retaining clips are standard I take it...
 

Briney Eye

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#20
I'll take this thing apart when I have some free time. This is the worst part of the year for me with kids being home, vacations, work, etc. but I'll get to it. Thanks for the reply. These retaining clips are standard I take it...
My kids are long gone and I still don't seem to have enough time :).

Like I said, download the manual from Vintage Machinery and check out the head assembly diagram. There might not be any screws in the 990-061 Pulley Sleeve Assembly, in which case you will need three #10-24 x 1/2 socket head cap screws. If they are (heaven forbid!) broken, your life just got a lot more interesting all of a sudden. If the pulley sleeve is loose it would explain the racket. Since there is a little radial slop in the assembly I shimmed the gap around the spline shaft to make sure it was centered before tightening the screws (and used Loc-Tite).
 

markba633csi

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#21
Someone had a procedure on rebuilding the head- if I can find the link I'll post it here
Mark
ps here you go:
 

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zakruvalcaba

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#22
Someone had a procedure on rebuilding the head- if I can find the link I'll post it here
Mark
ps here you go:
Thanks Mark. I'm not interested in rebuilding the head at this point but it gives me a good idea of how the pulley assembly is removed. In this PDF he had to remove the pulley with a puller. Clearly mine is moveable up and down by hand....so somethings a miss and so I'll start there and assume, for now, that that is the source of the noise....
 

markba633csi

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#23
OK understood, good little mill even if it needs a little fixing, I don't own one but I like to stockpile information just in case
Hello my name is MARK and I'm an information hoarder :cool 2:
 

wlburton

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OK understood, good little mill even if it needs a little fixing, I don't own one but I like to stockpile information just in case
Hello my name is MARK and I'm an information hoarder :cool 2:
I'm with you, Mark, about "hoarding" information, at least about machines that I own or expect to own one day (and I do own an 8520). Not being one to want to reinvent the wheel when I can help it, I have created 3-ring binders for most of my machines where I put whatever manuals, brochures, parts lists, write-ups of procedures, etc. I come across in the cornucopia of information available to us on the internet (most of which couldn't have been found anywhere pre-internet). I can sleep a little better knowing that if and when I need to rebuild the head of my 8520 I will have an excellent step-by-step guide to doing it. Also, the next owners of these machines will probably be ecstatic to have access to these "books" after the big estate sale!

I'm reading this thread almost like a mystery serial and I can't wait to find out what the issue turns out to be. The answer may well end up immortalized (printed out and lodged in a page protector) in my 8520 book!

Bill
 

zakruvalcaba

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I'm with you, Mark, about "hoarding" information, at least about machines that I own or expect to own one day (and I do own an 8520). Not being one to want to reinvent the wheel when I can help it, I have created 3-ring binders for most of my machines where I put whatever manuals, brochures, parts lists, write-ups of procedures, etc. I come across in the cornucopia of information available to us on the internet (most of which couldn't have been found anywhere pre-internet). I can sleep a little better knowing that if and when I need to rebuild the head of my 8520 I will have an excellent step-by-step guide to doing it. Also, the next owners of these machines will probably be ecstatic to have access to these "books" after the big estate sale!

I'm reading this thread almost like a mystery serial and I can't wait to find out what the issue turns out to be. The answer may well end up immortalized (printed out and lodged in a page protector) in my 8520 book!

Bill
I'm hoping it's simply a broken retainer clip that's causing the pulley to vibrate up and down and slap against the head. Like I mentioned in an earlier post, I reduced the speed to 600 RPM from the 1900 RPM that I had before and the machine sounds way better. Of course I'd like it to sounds exactly the same regardless of the speed I have it at. Perhaps I'll have some down time to work on it tonight.
 

markba633csi

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#26
Isn't the internet great!?
 

zakruvalcaba

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#27
So I'm 90% sure my noise is coming from my pulley being loose. I can't seem to pinpoint any other problem. I completely removed the cover and the noise is still there. So it's not the brake handle. I then attempted to remove the pulley. I started by attempting to remove the drive plate. I removed the two hex screws and the side spring loaded set screws but the drive plate seems to be fused to the pulley pretty good. The document for rebuilding the 8520 head makes it seem like this drive plate should just come right off....it doesn't. I also found the two set screws to be excessively loose. More on this in a bit. The video below shows me trying to slide the pulley up and off of the shaft but' it's binding on something. Again, I don't know WTF. So I gave up, slid the pulley back down and tightened the set screws. The pulley tightened up ok until I went to cut something. The pulley slid back up a tiny bit and the noise continued. Took the thing apart again and the pulley moves up and down. Granted it requires some effort to move up and down but it's moving nonetheless. I'm not sure what's going on with this thing and I just want it to work. I sold my Rong-Fu to buy this mill in part because of it's cult following and right now I just feel pretty annoyed... :(

 

Briney Eye

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#28
So I'm 90% sure my noise is coming from my pulley being loose. I can't seem to pinpoint any other problem. I completely removed the cover and the noise is still there. So it's not the brake handle. I then attempted to remove the pulley. I started by attempting to remove the drive plate. I removed the two hex screws and the side spring loaded set screws but the drive plate seems to be fused to the pulley pretty good. The document for rebuilding the 8520 head makes it seem like this drive plate should just come right off....it doesn't. I also found the two set screws to be excessively loose. More on this in a bit. The video below shows me trying to slide the pulley up and off of the shaft but' it's binding on something. Again, I don't know WTF. So I gave up, slid the pulley back down and tightened the set screws. The pulley tightened up ok until I went to cut something. The pulley slid back up a tiny bit and the noise continued. Took the thing apart again and the pulley moves up and down. Granted it requires some effort to move up and down but it's moving nonetheless. I'm not sure what's going on with this thing and I just want it to work. I sold my Rong-Fu to buy this mill in part because of it's cult following and right now I just feel pretty annoyed... :(

You'll get it figured out. Two socket head screws and two ground dowel pins hold and locate the plate on the top of the pulley. It's probably just old hardened oil glueing it together. Sharpen up a cold chisel and tap it into the seam between the plate and pulley, working all the way around the circumference. It should separate.

That's an interesting draw bar and threaded spindle you have there. I assume that you have the cap nut that screws onto the top of the spindle. I've heard of the mod, but not seen it. The flange on the draw bar is bigger than the depth of the splines, so the draw bar has to come all the way out. Your pulley sleeve has a much thicker flange than mine, and I hate to say it, but is that a break around the inside edge that I see? I'm afraid that the "sleeve" part has broken off from the flange, which would explain your whole issue. You will need to braze it back together or make a new one. Someone here can help you with that (maybe even me).

Don't give up. I had to deal with several issues on mine, including silver brazing the broken brake plate, but I've made it into a really nice machine.

-Jon
 

zakruvalcaba

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#29
Thanks for the guidance Jon, I got it apart (mostly). Not sure why I didn't think to remove the draw bar first. I can see that the pulley sleeve assembly is broken. Looking at the pictures up close, it looks pretty clear that someone had it break on them before and they attempted a fix that didn't hold. If that's the case, I may just make a new one. So with that said, two questions.

1) What's the best way to remove the broken portion of the pulley sleeve from the pulley without damaging the pulley? Press it out? Will the bearings just slide off or will they have to be pressed out as well? In the diagram, I see that there are 2 retainer clips in between the bearings so I'm not sure what the best way to get these off would be.

2) Is the pulley sleeve pressed into the flange or is it all one piece? If it's pressed in, what's the best way to remove the broken off piece that remains in the flange?

Thanks in advance for any help!

pulley1.jpg pulley2.jpg pulley3.jpg pulley4.jpg
 

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#30
Now that you have the top clip off, press the sleeve out through the pulley from the top. It should push the bottom bearing out with it. Impossible to say how much trouble the bearings will give you. Sometimes the bearings just fall out/off (a good or bad thing depending on your point of view). The top bearing in the rear cone pulley on mine was wallowed out several thousandths, and had to be sleeved and re-bored. I also sleeved and re-bored the brake ring contact surface in the front cone pulley. The end result was a very quiet machine and a brake that locks things up with just a little pressure on the lever.

I recommend replacing all of the bearings while you have it apart. They're standard sizes, and inexpensive. The only ones that I re-used were the thrust bearing on the knee screw and the quill bearings (but I have spares anyway).

-Jon
 
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