Re: [CAD_CAM_EDM_DRO] Re: Ball screw lubrication question - Follow up question

washcomp wrote:

>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.
>
>

Oh, OK, this isn't the old BOSS head with the coaxial ballscrew. This
is the Anilam-style, which Bridgeport now sells on their Ez-trak machines,
too. It is also the way I did it on my retrofit. No doubt, if you lube
the screw the balls will roll through the oil and carry the lube all through
the insides of the nut. Don't be too surprised if a bunch of ugly black
crud comes out on the screw right after you lube it and run it back and
forth
a couple of times. In fact, i've cleaned dirty nuts by greasing the screw
and running the screw through the nut a few times. the grease pulls all
the crud out of the innards of the nut.

>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?
>
>

Spindle oil is real light, SAE 5 or so. It is designed not to cause bearing
heating, which some heavier oils do cause. The oil is also a self-cleaning
mechanism, as it is continuously dripping out of the spindle.

Does this sign look like a factory-installed one? At least, the 1J and 2J
heads are not made that way. Some 3J and 4J heads are made with sealed
bearings, and can do so because they run at lower speeds.

The Bridgeport 1J and 2J heads, at least, have a lot of other stuff that
needs
some lube. The power feed worm (which may not even be there on a
CNC head) has a worm wheel on the spindle that needs lube when you use it.
The back gears need lube, too. And, the quill, itself, is supposed to be
lubed and may get a kind of washing action to keep chips from packing
into the fine clearance there, by the downward flow of oil. The spindle
splines also need some lube every once in a while.

Jon