Stretch Sewing Machine
1. A bent or dull needle
Sewing machine needle tips can only maintain their sharpness for about 6-8 hours of sewing time, so be sure to change your needle frequently. Even if you are not able to see obvious damage or dullness, if you have sewn a garment or two, it is definitely time to change your needle.
2. The wrong needle for your fabric
With the variety of fibers and weaves we have available to us in today's fabric stores, there is an accompanying variety of needles required to sew them correctly. In general, knit fabrics require a jersey or ballpoint tip. Most wovens do well with a universal tip, and specialty fibers, like leather or metallic, usually require specific needles. For more information on the right needle for the job, be sure to check out the Craftsy blog post, "How to Choose Sewing Machine Needles."
3. Incorrect machine threading
It is a good rule of thumb that if your stitching looks wacky for any reason, re-thread both the needle and bobbin to make sure you are following the manufacturer's directions correctly. Also be sure you are using good quality thread, not a spool that your great-grandmother bequeathed to you. Of all the components in your project, thread is the usually the cheapest, so buy the best you can find. Your sewing machine will thank you!
4. Unbalanced needle thread tension
I hesitate to suggest this remedy, because many people rush to use it first. It really is only a last resort, and often doesn't help much. The tension dials on sewing machines are generally set at the factory at the mid-point. Start by making relatively small changes and run a test stitch to evaluate the impact. If you need to adjust the tension dial using woven cotton fabric with good quality all-purpose thread and a new needle, it is time for a tune-up.
If none of the above remedies help, take your machine to a qualified sewing machine mechanic for a thorough tune-up.
Don't let common issues, like skipped stitches, keep you from using your sewing machine! In the FREE Craftsy class, Amy Alan shares tips for troubleshooting common sewing machine problems, including skipped stitches, crooked seams, needle and thread breakage, and more.