The South Bend SB1001 8×18 (8k) lathe is a quality bench top lathe. It would seem a great lathe as a base for a CNC lathe conversion. Reasons include minimal parts to discard following the conversion, a nice camlock spindle, and a variable speed DC motor. The conversion is difficult because the small crossfeed channel makes installing a ballscrew difficult.
First a 3D model of the lathe was made in SolidWorks by taking lots of measurements and hours of modeling. A CNC conversion is made using 3D printed parts, an Arduino, and closed-loop stepper motors. A video describes the process and demonstrates the results.
Make your own. The lathe model (and 3D printed parts) files are available for download!