Re: [CAD_CAM_EDM_DRO] Re: bridgeport ballscrew question

John Delaney wrote:

>I recently fitted my BP with a retro kit from Rockford Ball Screws.
>The screws and the nuts are great. Class A stuff. I have not put the
>motors on it yet. Now, I may have done something wrong too, not sure.
>I'm new at ALL of this. But when I run the Y all the way back or lock
>the saddle down, I can feel some spring in it with the manual crank.
>It reads about .002 - .004 on the dial. X is fine but there's no
>lever arm to flex there. The C/L of the screw is almost lined up with
>the table.
>
>

This is normal. With the Acme screw, you just don't get the sensitivity to
feel these things. It is likely that what you are actually feeling is
the saddle
tipping up off the ways, under the force from the screw. But, maybe not, as
you say you get it even with the saddle locked. I'd check for axial play in
the screw. If you didn't get the double ball bearing set put together
right,
it may allow a little end play in the screw. There are spacers on the
inner races,
and the clamp plate pushes the outermost outer race to preload the bearings.
It is also possible the bearings need to be replaced.

>
>

Jon