It's funny when I first started sewing no one ever said how often to change the needle - I used to think it was when it broke! When I started quilting someone told me to change it with each project but since I never work on just one project I usually change it once or twice a month depending on how much I am sewing. What a difference! It is probably the cheapest thing we can do in quilting and the one we do least often - with the exception of changing our rotary blades.