A newbie question

I am considering if a cnc conversion to a 9x20 (emco c8) would make
sense. I am an electronics engineer and should cope with the
electrical part of the project. But I lack any feeling as for what is
practically possible with an affordable low cost cnc conversion, dc
or stepper motor, without any positive position feedback via a linear
scale. I need the experience of those that already tried. Would you
feel it is possible with a simple motor on the cross slide lead
screw, to turn a shaft close to h7 tolerance? Chris