Unless I break one (sigh, happens), when I finish a quilt, I clean the sewing machine, oil/lube, and put in a new needle. I have mostly antique Singer sewing machines. However, I do have the Singer Anniversary, a Singer Curvy and an Elna and these 3 are newer (last 5 years old) and they don't need that kind of attention so I always put in a new needle and clean the bobbin area at the completion of a quilt on them.