Thanks for the suggestion. As most things, there appear to be various grades
of Mobile's DTE oils, and I'll spend some time looking into Light and the
others.

Yep, the balls want to hydroplane, but there's nowhere to go.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Gunner Asch" wrote in message
...
On Sun, 21 Dec 2008 23:38:22 -0500, "Wild_Bill"
wrote:

I know there are some folks here that have considerable experience with
high
speed parts and lubricating oils.
I anyone has recommendations for oils with properties suitable for high
speed bearings, I'd appreciate hearing them.

The spindle speeds in toolpost grinders can range from about 6k to 30k
RPM.

I haven't taken them apart to see exactly what types of bearings are used
in
the spindles, but I would expect them to be high precision ball bearing
assemblies. I've seen parts list prices of over $200 each for bearings
with
ODs of about 1.25".

I presently have two brands, Themac 1/2 HP and Dumore 1/4 HP.


At those speeds, most bearings will be running with air/oil misting and
a very light turbine oil such as DTE Light

Cavitation becomes a real problem at high speeds in oil baths, as does
the fact that oil isnt a compressible and too much tends to make the
balls in the race ride up and over the oil droplets, slamming back down
on the other side.

The same effect that makes potholes on the back side of speed bumps.

Gunner

"They couldn't hit an elephant at this dist..."
Maj. Gen. John Sedgewick, killed by a sniper in 1864 at the battle of
Spotsylvania