I am in the throws of planning the best way to convert my Myford VMC Mill to CNC, specifically the fitting of ballscrews is at the forefront of my deliberations.
Once dismantled, I will have no other milling capability and so I am considering making the ballnut housing and the ballscrew bearing blocks with oversize mounting holes and to tighten and shim everything using a guide rod through bearing and nut housing. Once everything is aligned, I will drill and ream for dowels. My uncertainty is whether I have any chance of obtaining a 900mm length of silver steel or PGMS that will be straight enough for the purpose.
Can anyone comment on what typical stock straightness is like??