As quilters we use our senses of vision and touch. You might not think about using your hearing, also. Listen to your machine when it is clean and correctly maintained, with correct tension, a new needle and full bobbin. Listen to it when stitching slowly and when sped up.
Remember the sound. It will help you recognize when attention is needed.
Is your needle dull? If so, it needs to punch its way through fabric layers, making a popping sound. When it is sharp, it doesn’t make that noise. In addition, your machine motor needs to work a little harder with a dull needle, and you may hear the machine laboring.
Experts recommend changing the needle every 8-10 hours of sewing (machine time, not cutting, pressing, and pondering). That may not sound like a lot, but if your machine stitches 1,000 stitches per minute, that’s actually about a HALF MILLION stitches! While you’re stitching, you may sew through several layers of fabric and batting, and occasionally hit pins. (I do!) Your needle takes a lot of abuse.
Take a look at some great photos by Schmetz Needles USA of a needle that looks sharp. Once magnified with increasing power, you can see the burr on the tip. A dull needle doesn’t do your machine or your project any good.
As for me, I don’t pay much attention to how long I sew between needles. Instead I try to pay attention to two things. I change the needle when it sounds dull, or when I’m beginning a new project (or phase of projects, if ya know what I mean.)
And please dispose of your needles carefully. I use an empty yogurt cup with a hole poked through the lid. When I get rid of needles, bent pins, and dead rotary cutter blades, they go in there. And the cup is always safely out of reach of children!
Does your machine need maintenance? That might seem scary or expensive, but basic maintenance begins with you and is easy to do. (Consult your machine’s manual. If you don’t have a copy, you may be able to find it online.) As with a dull needle, a dirty machine, clogged with lint, makes the motor work harder. The extra work sounds different. You may not be able to describe the difference, but you can probably hear it.
Maintenance you can and should do includes cleaning the lint out of the works. A soft brush may have come with the machine. If not, small, soft make-up brushes work well. Cotton swabs and tweezers may come in handy, too.
Remove the foot, needle, and face plate. Take out the bobbin. You may want to remove the bobbin case, too. Again, consult your manual. Use the brush to loosen and grab lint around the bobbin case, in the feed dogs, and around other surfaces. The cotton swab and tweezers may help, depending on where and how your mess is lodged. Some manufacturers recommend using compressed air to remove built-up lint gunk. Others warn against it. Please check first.
How often should you clean? That will depend partly on what thread you use (some is lintier than others) and on your fabrics and/or battings. As a quilter, I rarely care what color of bobbin thread I use while piecing, and I sew until it runs out. I clean every 3-5 times I change my bobbin. If I’m changing the bobbin and the mess is evident, I clean.
You may wonder if and how to oil your machine. Many modern machines have self-lubricating parts and don’t need oiling. Others have simple routines recommended for oiling regularly.
Your machine’s manufacturer probably has a recommended cycle for shop maintenance. Consult your manual or dealer for advice.
Is the bobbin full and wound correctly? Of course, you don’t have a full bobbin most of the time! Fancier bells-and-whistles machines may give you a warning just before the bobbin runs out. Mine does not. But on my machine, it sounds just a little bit different when full than when nearly empty.