Re: [CAD_CAM_EDM_DRO] Re: CNC bridgeport

Rebel307 wrote:

>so I need to look for a bridgy with a good head and not much else. I dont
>mind the worne out lead screws cause they will be changed to ball screws.
>What about the ways being worn a little, can that be adjusted out?
>
>

No. The wear is generally near the center of the ways, causing the table
to be loose at that point, and also to move in an arc-like motion as the
concave curved bottom of the table passes over the convex top of the
saddle. If you find a machine with chromed ways, it is much more
likely to be in good shape. The frosting marks on the bottom of the
table will tell the story pretty well. If you move the table to one end,
and the frosting marks in the center are still nearly as sharp as at the
ends,
that is a very good sign. If the marks are almost gone in the center, that
means a few thousandth of an inch of metal are gone in the middle.

On some machines the vertical ways for the knee are also worn out,
as the knee slide is under huge force. This allows the knee to rock,
causing the table to move in and out a few thousandths of an inch
when the knee is cranked up and down. This pretty much prohibits
using the vertical slide when machining.

Jon