can anyone help me out with the "average" ballscrew diameter for benchtop mills such as the grizzly's, IH's, and rong fu's? or better yet if im going to buy a mill and then retrofit it by piecing together parts myself, what diameter ballscrews should i be looking at. im planning on buying an IH mill and retrofitting it for cnc in a couple of months when i get the money...and ive been looking around on ebay at some ballscrews but dont know how big/little is too big/little (diameter).

also anyone with an IH mill what length ballscrews should i use?

thanks for any help or answers,
-rene

i'm going to use a 5/8 ballscrew on my first conversion. its the cheapest one available. on my IH conversion i haven't decided what i'm going to use yet but i think it will be bigger.

yeah im seeing some nice 3/4" that im thinking of using....im just wondering about clearance issues...grinding is not a problem to gain some extra clearance if posisble- i just wouldnt want to grind so much that it might make it significantly weaker structurally....