Ball screws

Hi,

     I am a newbie to the world of CNCs so i apologise for any impertinent questions and mistakes.

I read online that a ball screw is a must if you want to build a CNC machine.The reasons being that the backlash or 'Play' that is always present in other screws is not tolerated.I also read that requirements are a little bit flexible for homemade CNC lathes.

My first question is,How are ball screws made?

I have not been able to to find much about their manufacturing process despite using a variety of methods.By profession I have a small workshop where I have a thread whirling attachment (Locally made,not sandvik) and can resonably grind a tool well enough to make threads of any profile.So please guide me about their making process

My second question is,Can I bypass ball screws and use simple lead screw and nuts to retrofit a steel turning lathe into CNC?

I am asking this question because i do not have the funds to make a small prototype CNC lathe and then implement to a larger lathe.And ball screws cost a bomb to acquire.So what are other options to having a ball screw for lathes.I am also assuming that funds are little bit tight always when you want to go on such projects.Please forgive me if I'm wrong.

All ideas are welcome and any help will be gratefully appreciated.