Ballscrew or leave alone?

[Jonathan]

You can get 12mm (RM1204) ballscrews from linearmotionbearings2008 on eBay. The steel the ballnuts is made from is just about soft enough to mill, so if you need to make them a bit smaller that's a cheap option. It's probably easier to grind it and glean the nut thoroughly afterwards. Clearly the stiffness and critical speed of the screw are both reduced if it's smaller, however in this instance neither is significant since it's a small machine.

[Ross77]

Have you got any space between the base and end plate on the bottom axis (Y- I think on a mill)? I'm just looking to put ballscrews on my mill and want the biggest diameter possible as it is only supported on one end. The channel between the ways is too small for 20mm dia. ball nut but I have space to move it forward and mount the nut flange on the face of the base.

Any way just a thought.