Re: Ball screw lubrication question - Follow up question

Jon:

The way they retrofit the Z-axis is by mounting the whole arraingment
externally. They attached the nut to a bracket and the bracket is
attached through the slot in the front of the spindle to the hole in
the spindle (quill?). There is no way to get lubricant from the
spindle to the Z axis. I'll take your advice and put some way oil on
the threads and hope the balls pick it up.

On a related question: There is a sign on my BP that says "This head
has grease packed bearings - Do NOT oil". Does this likely refer to
the spindle or should I still use oil there? What are the
carachteristics of spindle oil which make it different from WAY oil?

Thanks and regards,
Jeff

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
> washcomp wrote:
>
> >A have lube points on everything but the Z axis ball screw on my
BP.
> >I'm using the original retrofit that came with the machine and
can't
> >figure a resonable way to get automatic lube to it. Its also a
> >disassembly job to get to, so I'd like to figure a way to lube it
and
> >forget it for a while (and also know when to relube). What should
I
> >use as a lubricant? The nut seems to be pretty sealed. Where/how
do
> >I lubricate this? How long should the lubrication last?
> >
> >
> Apparently the standard Bridgeport quill is lubed by oil flung off
the
> spindle
> when it is running. It hits the wall of the main housing and
slides down,
> lubing the outside of the quill. I don't know if that would work
with the
> integral ballscrew quill, but is seems like it could work there,
too.
>
> I have not seen any Bridgeports with auto-lube to the head. I
would think
> you could add a port to the auto-lube system, with its own metering
orifice,
> to drip a little oil somewhere into the head that would get on the
quill.
> From there, it would have to run down onto the nut. It seems
unlikely the
> nut is actually "sealed", unless you mean just totally enclosed in
the head
> casting. Yes, that sounds about right, all the Bridgeport heads
are like
> that.
>
> My personal preference for the nut, alone, would be a light
grease. But,
> that may be incompatible with the very tight fit of the quill in
the bore
> of the head. Some people report that greases there will cause
binding,
> or at least stiffness, and that only oil should be used. (Mine has
some
> wear, and was packed with debris when I got it, and I used grease to
> grab the debris and draw it out.)
>
> My guess is that if you use a sticky oil (way oil) or grease, it
should
> last for months, as it really has nowhere to go. A plain, light
oil would
> tend to slide down the quill, and might need to be replenished
weekly
> or so.
>
> Jon