Do stepper motors wear out ?


Just asking the question, I've read that stepper motors don't wear out.

But after fitting a Masso control last year to my self built cnc Plasma ( built 19 years ago ), it produced the smoothest cuts ever done. This was with my developed THC stand alone control.

Just recently noticed I was getting a jagged shark tooth cut situation.

Over the weekend I have replaced both X and Y axis stepper motors, bingo, clean and neat cut again.

Gained superior traversing speed, stronger holding torque, more accuracy.

What's your thoughts ?

This machine was built 19 years ago, first one.