Sandy told us her sink stopper wasn’t stopping any water from going down the drain and we discovered it was the ball rod — it was rusted ...

Making the nut softer than the rod (for example, brass or Delrin) is another common optimization. However, when lead screws aren’t good enough, mechanical designers turn to ball screws.

The bearings actually squeeze the rod a little bit, making a temporary indentation in the surface that works just like a screw thread would. As the bearings roll on, the rod bounces back to its ...