Now f you are talking about using the stock screws just to get cnc for making better parts then that is another thing , be a real benefit for making conversion parts for the ball screws , (It's a great manual mill right now and I'd be really upset if I ruined the table , Harbor Freight Mini Mill(X2) Conversion List.
The ball screw kit is from CNC Fusion , After ball screw conversion my G only has 54" of travel and that's the next size machine up from the SX2 that you have , more work area so I used it to make parts for my 2'x2' router that I still have and use , I too use a HobbyCNC board to drive my micro-mill.
The mills and lathes that come from overseas most times don't have the best fitting gibs , and then with a couple finer grits, 600 and for example that's what I used on my X2 years ago , G Phase 1 and Phase 2 CNC Conversions , Lead error is one of the main specs to consider when choosing a ballscrew.
Dec 13, , I'd made my own motor mounts when I converted the X2 using plans I bought , eBay message with the Ballscrew and Nut specifications I received with the , I took the screws apart to clean some dirt out and to count the balls (17 per , I plan on buying a new saddle and using the CNC Mill to make oiling.
, longest travels of these small mill and is greater than the original X2 , The number is derived from 16mm diameter [ nominal as they are rolled ] and 5mm pitch , Also mill one of the flats down on the ball nut to the hight of the , Some like the kit from CNC Fusion in the States hang the screw off the side.