In principle, these are very similar to lead screws but instead of a nut, there is a race containing ball bearings that moves up and down the screw. The ball bearings lead to less friction.

The screw itself wasn’t too hard to cut ... And if you want a little more detail on lead screws and ball screws, we’ve got just the article for that.

Lead screws usually incorporate proprietary screw and nut geometries and materials ... This design features both left-hand and right-hand threads. With left-hand threads, the ball nut travels away ...

Lead Screw Lead screws drive a nut in linear motion via direct contact with the nut ... Left Hand Thread The direction of the threads on the screw shaft causing the ball nut to travel away from the ...