[Wade C]

95 Fadal 4020HT

Im guessing that means thrust bearings, but thought I better check in here in case I should be looking at other things while Im in there digging around.

Feeding at 20 IPM it was about every second and a half or two seconds that it would grumble. Just sounded like a bearing that got water in it (in this case DowFrost likely) and pitted and rusted at the bottom where it collected.

But Im not finding any leaks around yet... but havent busted out the inspection mirror, flash light, and such yet... so I could just be missing it.

Backlash on the Y axis isnt horrible at .0009 - .0011 depending on where on the screw it is.
What is odd to me, is its only making noise when going Y-. When it feeds in Y+ is has the cyclical grumble and you can feel it vibrate the machine.

Expected more backlash if the thrust bearings were bad, but maybe I caught it just in time. And not really noticeable at rapid speed. But definitely tied to screw speed. Faster feed = faster grumble cycle.

Ill have to do some more digging when I get time. Hoping Im on the right path, have a spare set of bearings and seals on hand.

Will also have to chase a oil drip (grease packed spindle) at the head. Dripping off of the droop of the chiller tube out of the nose of the spindle and the little line above it (not sure what that carries - anyone know? maybe air? its on the mounting flange above the chiller line on the exposed portion of the spindle cartidge). Very light oil, Im guessing from the range shift cylinders, but need to pull the cover to confirm. If I have to get in there for the cylinders, may just do the bellevilles and belts as I have them on hand as well.

Open to thoughts. I posted this on PM, and got a reference to possible carbon tracking or a card interface issue. Not sure what to do about the carbon tracking, but still researching that... and will reseat cards in the next day or so. At least I have some time and dont have to have the machine right away, so I have some time to research instead of just throwing money at it.

Wade

[Drassk]

Take this advice as worth what you paid for it, but when I had a cyclical noise on my machine it was the tachometer causing it. I pulled off the end cap and cleaned off the tach with a swab dipped in ethanol while it was moving slowly and the noise mostly went away.

[CNC Viking]

I had also a very noisy Y-axis last year. It turned out to be a faulty servo driver (amp). It has worked perfect since I changed the driver.

You will find my thread about it here.
http://www.cnczone.com/forums/mazak_...oud_noice.html