My Kondia FV-1 turrett mill developed noise in the upper pulley area.
The back-gear toothed belt was tracking low, shedding debris and showed a small tear.

A tear down revealed suspect pulley support bearings, which were duly replaced.

Re-assembly left the toothed belt on the bench.
This a CNC mill with low usage of the back-gear and a VFD that enables a speed of 115 RPM off the normal low-speed pulley.

On test, the noise is now very good, but I am monitoring closely to see if some of the observed noise indicates main spindle bearings.

The attached drawings are taken form the handbook and show the upper spindle area.
Very similar to a Bridgeport, but different in detail.

Kondia Handbook Spindle compr .JPGKondia Handbook Pulley Bearing compr.JPG

The main lubrication entry is Item 504, a standard hinged cap.
Oil path is on to the back-gear, down past the feed take-off, through the filters, through the top spindle bearing, down the quill, through the bottom spindle bearings and discharge from the quill.

For the pulley support bearings, there is a mystery, shields and lubrication.

The handbook lists as two x 6207-Z.
The SKF data sheet shows this designation as a single shield.
The drawing shows these bearings with a different detail on their two sides.
One could infer the upper bearing has the single shield at the bottom, the bottom bearing with the single shield at the top.
Removed from the mill were double shielded labelled NSK 6207Z.

Item 585 is a listed as a Lubricator RM-6, recessed into the outer bearing nut.
When removed it had a M6 thread, a concave end, an internal sprung-ball and a screw-driver slot.
It is virtually an oil zerk fitting as used on lathes etc.
When used, oil would squirt out of the screwdriver slots, unless Kondia supplied a special oil-can fitting of some sort.
The Handbook advice for oil does show a point in this area, but I had always taken that to be the spindle splines, so no oil was ever applied to this zerk.

Inspection of the drawing shows oil through the zerk is virtually obstructed by the outer ring of the bearing.
Then it has to pass through at least one shield to get to the bottom bearing, another shield, then would pool in the bottom of the pulley.
None of this seemed sensible.
There was only a small quantity of oil/grease/dirt on the pulley where any oil would deposit.

After consideration, I elected to go with double shields, Nachi 6207 ZZE.

Question: Should I apply oil through the zerk ?

Apologies for the long post, but I thought the subject interesting.
Keep well,
John.
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