Lathe CNC retrofit

Hi All -

I've been thinking about CNC'ing my Sharp 13x30, and I'm wondering
what the max loads are that the leadscrews see during typical
cutting? By the nature of the lathe design, it seems the majority
of the cutting forces are directed downward against the ways. I
don't remember feeling the same resistance at the handwheels while
"lathing" as I do on my mill. I'd like to see about using
spring-loaded anti-backlash nuts instead of trying to mount
ballscrews, but I need some sort of load rating to go by. OTOH,
could I adjust the half-nuts to eliminate the backlash? Has
anyone done this?

TIA,

Carlos Guillermo
VERVE Engineering & Design