There has been alot of talk by sewers/quilters recently about when to change your sewing/quilting machine needles.
Many people say that the best practice is to change the needle every time you begin a new project. Although this may work best for some, others say this is not the best economical solution, especially in this day and age. My dilemma with this practice is that I often have several projects going at one time and don't neccessarily begin one and work on it exclusively until it is finished.
I've even heard of some people trying to straighten bent needles to reuse in their machines. I do not recommend this practice. I am not willing to chance that I might do damage to my machine in an attempt to save a needle.
I change my needles when they break (obviously), get bent, or start to dull and make that little popping sound as they enter and leave the fabric.
I will however, share a little tip with you that can lengthen the life of a needle for a little while. When a needle (hand or machine) starts to dull, stick it in and out of the little strawberry attached to your tomatoe pincushion a few times. It will glide through your fabric again!!!