Re: What Grease

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
> wanliker@a... wrote:
>
> >For those that are using high speed spindles in there conversions,

what

> >grease are you using in the bearings?
> >
> >
> If you are going much over 5000 RPM, you probably don't want any
> grease at all. For higher speed, a small amount of oil is a lot better,
> as it produces less heat.
>
> Jon
>

Check the bearing manufacturer.

the oil used at low speed is thicker than for high speed as the
bearings get hotter, they expand and the viscosity plays rolls both in
heat and lubrication.

Reading about synthetic oils and it appears that in WWII, the reason
synthetic was needed (besides it being able to work in temperatures
that would burn off petrolium oils) was that it was so much more
cosistant.

refined oils at that time were full of junk. today, the standard oils
are so much higher quality, they are said to surpass the synthetics of
those early years.

True synthetics may have additives that nind with the metals created
an even more slipper surface.

My lathe spindle (old south bend) does not have ball bearings, but is
just metal seperated by a thin sheet of oil. Evidently, South Bend
recomends one viscosity for low speed and a different viscosty for
high speed.

But, I have been using a CAstro Synth-blend as way oil and it looks a
lot wetter than anything else, and it just holds the surface. I am
impressed.

Dave