I had a lot of backlash in the cross slide feed screw, which made it inconvenient to use and difficult to turn accurately. I have had the notion to change it to a ball screw running around in my mind for quite some time and recently I bit the bullet.
Here is a video link:
The original lead screw was 15 mm in diameter, the ball screws came in 16 and 14 mm. I choose the 16 mm which was a mistake, you can see in the video how much I had to cut off the ball nut to get it to fit. The 14 mm size would have made that easier and still been perfectly adequate. We live and learn.
I am over the moon with the results of the conversion and have no hesitation in recommending it to anyone. There were some tricky setups needed to machine things accurately but they are fully explained in the video. Here are a few stills.
Click thumbnails for full size.