All lathes unless equipped with ball screws have backlash in the crossslide
& compound screws. While turning there is continous pressure against the
tool so backlash really doesn't matter, assuming your tool is above or at
center. If you let your tool below center it can get dragged into the work,
for instance when parting off.

I wouldn't worry about it unless the backlash is more than 3/4 of a turn, &
then only because it becomes difficult to remember where the correct reading
is when approaching the surface of the work.

Rigidity comes more from the snuggness of your gibs.

Tony

"Grant Erwin" wrote in message
...
I have a venerable 1949 South Bend 9" lathe. Sadly, its cross-slide nut
(or
screw, or both) have a fair amount of wear, as I can grab the cross-slide
table
and move it nearly 1/16" with my hands. I'm whittling down a block of 303
stainless and it seems like it's taking forever. The machine is cutting
the 303,
but I can only advance the cutter about .010" between passes, and reducing
the
diameter .020" at a time is going to mean a lot of lathe work. I don't
really
have to do it, of course, but it has led me to wonder if the slop in my
cross-slide screw actually contributes to lack of rigidity while turning.
I have
always figured as long as the slack in the screw was taken up, it wouldn't
make
any difference whether there were .004" of backlash or .040". Yet I don't
have a
complete understanding so I thought I'd post this to the group. There is
an
advertiser in HSM that offers new cross-slide nuts and screws for my lathe
at
what seems like a reasonable price.

GWE